4101:1-23-01 Wood.

[Comment: When a reference is made within this rule to a federal statutory provision, an industry consensus standard, or any other technical publication, the specific date and title of the publication as well as the name and address of the promulgating agency are listed in rule 4101:1-35-01 of the Administrative Code. The application of the referenced standards shall be limited and as prescribed in section 102.5 of rule 4101:1-1-01 of the Administrative Code.]

SECTION 2301

GENERAL

2301.1 Scope. The provisions of this chapter shall govern the materials, design, construction and quality of wood members and their fasteners.

2301.2 General design requirements. The design of structural elements or systems, constructed partially or wholly of wood or wood-based products, shall be in accordance with one of the following methods:

1. Allowable stress design in accordance with Sections 2304, 2305 and 2306.

2. Load and resistance factor design in accordance with Sections 2304, 2305 and 2307.

3. Conventional light-frame construction in accordance with Sections 2304 and 2308.

4. The design and construction of log structures shall be in accordance with the provisions of ICC 400.

2301.3 Nominal sizes. For the purposes of this chapter, where dimensions of lumber are specified, they shall be deemed to be nominal dimensions unless specifically designated as actual dimensions (see Section 2304.2 ).

SECTION 2302

DEFINITIONS

2302.1 Definitions. The following words and terms shall, for the purposes of this chapter, have the meanings shown herein.

ACCREDITATION BODY. An approved, third-party organization that is independent of the grading and inspection agencies, and the lumber mills, and that initially accredits and subsequently monitors, on a continuing basis, the competency and performance of a grading or inspection agency related to carrying out specific tasks.

BRACED WALL LINE. A series of braced wall panels in a single story that meets the requirements of Section 2308.3 or 2308.12.4.

BRACED WALL PANEL. A section of wall braced in accordance with Section 2308.9.3 or 2308.12.4.

COLLECTOR. A horizontal diaphragm element parallel and in line with the applied force that collects and transfers diaphragm shear forces to the vertical elements of the lateral-force-resisting system and/or distributes forces within the diaphragm.

CONVENTIONAL LIGHT-FRAME CONSTRUCTION. A type of construction whose primary structural elements are formed by a system of repetitive wood-framing members. See Section 2308 for conventional light-frame construction provisions.

CRIPPLE WALL. A framed stud wall extending from the top of the foundation to the underside of floor framing for the lowest occupied floor level.

DIAPHRAGM, UNBLOCKED. A diaphragm that has edge nailing at supporting members only. Blocking between supporting structural members at panel edges is not included. Diaphragm panels are field nailed to supporting members.

DRAG STRUT. See "Collector."

FIBERBOARD. A fibrous, homogeneous panel made from lignocellulosic fibers (usually wood or cane) and having a density of less than 31 pounds per cubic foot (pcf) (497 kg/m3)but more than 10 pcf (160 kg/m3).

GLUED BUILT-UP MEMBER. A structural element, the section of which is composed of built-up lumber, wood structural panels or wood structural panels in combination with lumber, all parts bonded together with structural adhesives.

GRADE (LUMBER). The classification of lumber in regard to strength and utility in accordance with American Softwood Lumber Standard DOC PS 20 and the grading rules of an approved lumber rules-writing agency.

HARDBOARD. A fibrous-felted, homogeneous panel made from lignocellulosic fibers consolidated under heat and pressure in a hot press to a density not less than 31 pcf (497 kg/m3).

NAILING, BOUNDARY. A special nailing pattern required by design at the boundaries of diaphragms.

NAILING, EDGE. A special nailing pattern required by design at the edges of each panel within the assembly of a diaphragm or shear wall.

NAILING, FIELD. Nailing required between the sheathing panels and framing members at locations other than boundary nailing and edge nailing.

NATURALLY DURABLE WOOD. The heartwood of the following species with the exception that an occasional piece with corner sapwood is permitted if 90 percent or more of the width of each side on which it occurs is heartwood.

Decay resistant. Redwood, cedar, black locust and black walnut.

Termite resistant. Redwood, Alaska yellow-cedar, Eastern redcedar and both heartwood and all sapwood of Western redcedar.

NOMINAL SIZE (LUMBER). The commercial size designation of width and depth, in standard sawn lumber and glued-laminated lumber grades; somewhat larger than the standard net size of dressed lumber, in accordance with DOC PS 20 for sawn lumber and with the AF&PA NDS for glued-laminated lumber.

PARTICLEBOARD. A generic term for a panel primarily composed of cellulosic materials (usually wood), generally in the form of discrete pieces or particles, as distinguished from fibers. The cellulosic material is combined with synthetic resin or other suitable bonding system by a process in which the interparticle bond is created by the bonding system under heat and pressure.

PREFABRICATED WOOD I-JOIST. Structural member manufactured using sawn or structural composite lumber flanges and wood structural panel webs bonded together with exterior exposure adhesives, which forms an "I" cross-sectional shape.

SHEAR WALL. A wall designed to resist lateral forces parallel to the plane of a wall.

Shear wall, perforated. A wood structural panel sheathed wall with openings, that has not been specifically designed and detailed for force transfer around openings.

Shear wall segment, perforated. A section of shear wall with full-height sheathing that meets the height-to-width ratio limits of Section 4.3.4 of AF&PA SDPWS.

STRUCTURAL COMPOSITE LUMBER. Structural member manufactured using wood elements bonded together with exterior adhesives. Examples of structural composite lumber are:

Laminated veneer lumber (LVL). A composite of wood veneer sheet elements with wood fibers primarily oriented along the length of the member.

Parallel strand lumber (PSL). A composite of wood strand elements with wood fibers primarily oriented along the length of the member.

STRUCTURAL GLUED-LAMINATED TIMBER. An engineered, stress-rated product of a timber laminating plant, comprised of assemblies of specially selected and prepared wood laminations in which the grain of all laminations is approximately parallel longitudinally and the laminations are bonded with adhesives.

SUBDIAPHRAGM. A portion of a larger wood diaphragm designed to anchor and transfer local forces to primary diaphragm struts and the main diaphragm.

TIE-DOWN (HOLD-DOWN). A device used to resist uplift of the chords of shear walls.

TREATED WOOD. Wood and wood-based materials that use vacuum-pressure impregnation processes to enhance fire retardant or preservative properties.

Fire-retardant-treated wood. Pressure-treated lumber and plywood that exhibit reduced surface-burning characteristics and resist propagation of fire.

Preservative-treated wood. Pressure-treated wood products that exhibit reduced susceptibility to damage by fungi, insects or marine borers.

WOOD SHEAR PANEL. A wood floor, roof or wall component sheathed to act as a shear wall or diaphragm.

WOOD STRUCTURAL PANEL. A panel manufactured from veneers, wood strands or wafers or a combination of veneer and wood strands or wafers bonded together with waterproof synthetic resins or other suitable bonding systems. Examples of wood structural panels are:

Composite panels. A wood structural panel that is comprised of wood veneer and reconstituted wood-based material and bonded together with waterproof adhesive;

Oriented strand board (OSB). A mat-formed wood structural panel comprised of thin rectangular wood strands arranged in cross-aligned layers with surface layers normally arranged in the long panel direction and bonded with waterproof adhesive; or

Plywood. A wood structural panel comprised of plies of wood veneer arranged in cross-aligned layers. The plies are bonded with waterproof adhesive that cures on application of heat and pressure.

SECTION 2303

MINIMUM STANDARDS AND QUALITY

2303.1 General. Structural sawn lumber; end-jointed lumber; prefabricated wood I-joists; structural glued-laminated timber; wood structural panels, fiberboard sheathing (when used structurally); hardboard siding (when used structurally); particleboard; preservative-treated wood; structural log members; structural composite lumber; round timber poles and piles; fire-retardant-treated wood; hardwood plywood; wood trusses; joist hangers; nails; and staples shall conform to the applicable provisions of this section.

2303.1.1 Sawn lumber. Sawn lumber used for load-supporting purposes, including end-jointed or edge-glued lumber, machine stress-rated or machine-evaluated lumber, shall be identified by the grade mark of a lumber grading or inspection agency that has been approved by an accreditation body that complies with DOC PS 20 or equivalent. Grading practices and identification shall comply with rules published by an agency approved in accordance with the procedures of DOC PS 20 or equivalent procedures. In lieu of a grade mark on the material, a certificate of inspection as to species and grade issued by a lumber grading or inspection agency meeting the requirements of this section is permitted to be accepted for precut, remanufactured or rough-sawn lumber and for sizes larger than 3 inches (76 mm) nominal thickness. Approved end-jointed lumber is permitted to be used interchangeably with solid-sawn members of the same species and grade.

2303.1.2 Prefabricated wood I-joists. Structural capacities and design provisions for prefabricated wood I-joists shall be established and monitored in accordance with ASTM D 5055.

2303.1.3 Structural glued-laminated timber. Glued-laminated timbers shall be manufactured and identified as required in ANSI/AITC A 190.1 and ASTM D 3737.

2303.1.4 Wood structural panels. Wood structural panels, when used structurally (including those used for siding, roof and wall sheathing, subflooring, diaphragms and built-up members), shall conform to the requirements for their type in DOC PS 1 or PS 2. Each panel or member shall be identified for grade and glue type by the trademarks of an approved testing and grading agency. Wood structural panel components shall be designed and fabricated in accordance with the applicable standards listed in Section 2306.1 and identified by the trademarks of an approved testing and inspection agency indicating conformance with the applicable standard. In addition, wood structural panels when permanently exposed in outdoor applications shall be of exterior type, except that wood structural panel roof sheathing exposed to the outdoors on the underside is permitted to be interior type bonded with exterior glue, Exposure 1.

2303.1.5 Fiberboard. Fiberboard for its various uses shall conform to ASTM C 208. Fiberboard sheathing, when used structurally, shall be identified by an approved agency as conforming to ASTM C 208.

2303.1. 5.1 Jointing. To ensure tight-fitting assemblies, edges shall be manufactured with square, shiplapped, beveled, tongue-and-groove or U-shaped joints.

2303.1. 5.2 Roof insulation. Where used as roof insulation in all types of construction, fiberboard shall be protected with an approved roof covering.

2303.1. 5.3 Wall insulation. Where installed and fireblocked to comply with Chapter 7, fiberboards are permitted as wall insulation in all types of construction. In fire walls and fire barriers, unless treated to comply with Section 803.1 for Class A materials, the boards shall be cemented directly to the concrete, masonry or other noncombustible base and shall be protected with an approved noncombustible veneer anchored to the base without intervening airspaces.

2303.1. 5.3.1 Protection. Fiberboard wall insulation applied on the exterior of foundation walls shall be protected below ground level with a bituminous coating.

2303.1.6 Hardboard. Hardboard siding used structurally shall be identified by an approved agency conforming to CPA/ANSI A 135.6. Hardboardunderlayment shall meet the strength requirements of 7/32-inch ( 5.6 mm) or 1/4 -inch ( 6.4 mm) service class hardboard planed or sanded on one side to a uniform thickness of not less than 0.200 inch ( 5.1 mm). Prefinished hardboard paneling shall meet the requirements of CPA/ANSI A 135.5. Other basic hardboard products shall meet the requirements of CPA/ANSI A 135.4. Hardboard products shall be installed in accordance with manufacturer's recommendations.

2303.1.7 Particleboard. Particleboard shall conform to ANSI A 208.1. Particleboard shall be identified by the grade mark or certificate of inspection issued by an approved agency. Particleboard shall not be utilized for applications other than indicated in this section unless the particleboard complies with the provisions of Section 2306.5.

2303.1. 7.1 Floor underlayment. Particleboard floor underlayment shall conform to Type PBU of ANSI A 208.1. Type PBU underlayment shall not be less than1/4-inch ( 6.4 mm) thick and shall be installed in accordance with the instructions of the Composite Panel Association.

2303.1.8 Preservative-treated wood. Lumber, timber, plywood, piles and poles supporting permanent structures required by Section 2304.11 to be preservative treated shall conform to the requirements of the applicable AWPA Standard U1 and M4 for the species, product, preservative and end use. Preservatives shall be listed in Section 4 of AWPA U1. Lumber and plywood used in wood foundation systems shall conform to Chapter 18.

2303.1. 8.1 Identification. Wood required by Section 2304.11 to be preservative treated shall bear the quality mark of an inspection agency that maintains continuing supervision, testing and inspection over the quality of the preservative-treated wood. Inspection agencies for preservative-treated wood shall be listed by an accreditation body that complies with the requirements of the American Lumber Standards Treated Wood Program, or equivalent. The quality mark shall be on a stamp or label affixedtothe preservative-treated wood,and shall include the following information:

1. Identification of treating manufacturer.

2. Type of preservative used.

3. Minimum preservative retention (pcf).

4. End use for which the product is treated.

5. AWPA standard to which the product was treated.

6. Identity of the accredited inspection agency.

2303.1. 8.2 Moisture content. Where preservative-treated wood is used in enclosed locations where drying in service cannot readily occur, such wood shall be at a moisture content of 19 percent or less before being covered with insulation, interior wall finish, floor covering or other materials.

2303.1.9 Structural composite lumber. Structural capacities for structural composite lumber shall be established and monitored in accordance with ASTM D 5456.

2303.1.10 Structural log members. Stress grading of structural log members of nonrectangular shape, as typically used in log buildings, shall be in accordance with ASTM D 3957. Such structural log members shall be identified by the grade mark of an approved lumber grading or inspection agency. In lieu of a grade mark on the material, a certificate of inspection as to species and grade issued by a lumber grading or inspection agency meeting the requirements of this section shall be permitted.

2303.1.11 Round timber poles and piles. Round timber poles and piles shall comply with ASTM D 3200 and ASTM D 25, respectively.

2303.2 Fire-retardant-treated wood. Fire-retardant-treated wood is any wood product which, when impregnated with chemicals by a pressure process or other means during manufacture, shall have, when tested in accordance with ASTM E 84 or UL 723, a listed flame spread index of 25 or less and show no evidence of significant progressive combustion when the test is continued for an additional 20-minute period. Additionally, the flame front shall not progress more than 10½ feet (3200 mm) beyond the centerline of the burners at any time during the test.

2303.2.1 Pressure process. For wood products impregnated with chemicals by a pressure process, the process shall be performed in closed vessels under pressures not less than 50 pounds per square inch gauge (psig) (345 kPa).

2303.2.2 Other means during manufacture. For wood products produced by other means during manufacture, the treatment shall be an integral part of the manufacturing process of the wood product. The treatment shall provide permanent protection to all surfaces of the wood product.

2303.2.3 Testing. For wood products produced by other means during manufacture, other than a pressure process, all sides of the wood product shall be tested in accordance with and produce the results required in Section 2303.2. Wood structural panels shall be permitted to test only the front and back faces.

2303.2.4 Labeling. Fire-retardant-treated lumber and wood structural panels shall be labeled. The label shall contain the following items:

1. The identification mark of an approved agency in accordance with Section 1703.5.

2. Identification of the treating manufacturer.

3. The name of the fire-retardant treatment.

4. The species of wood treated.

5. Flame spread and smoke-developed index.

6. Method of drying after treatment.

7. Conformance with appropriate standards in accordance with Sections 2303.2.2 through 2303.2.5.

8. For fire-retardant-treated wood exposed to weather, damp or wet locations, include the words "No increase in the listed classification when subjected to the Standard Rain Test" (ASTM D 2898).

2303.2.5 Strength adjustments. Design values for untreated lumber and wood structural panels, as specified in Section 2303.1, shall be adjusted for fire-retardant-treated wood. Adjustments to design values shall be basedonan approved method of investigation that takes into consideration the effects of the anticipated temperature and humidity to which the fire-retardant-treated wood will be subjected, the type of treatment and redrying procedures.

2303.2. 5.1 Wood structural panels. The effect of treatment and the method of redrying after treatment, and exposure to high temperatures and high humidities on the flexure properties of fire-retardant-treated softwood plywood shall be determined in accordance with ASTM D 5516. The test data developed by ASTM D 5516 shall be used to develop adjustment factors, maximum loads and spans, or both, for untreated plywood design values in accordance with ASTM D 6305. Each manufacturer shall publish the allowable maximum loads and spans for service as floor and roof sheathing for its treatment.

2303.2. 5.2 Lumber. For each species of wood that is treated, the effects of the treatment, the method of redrying after treatment and exposure to high temperatures and high humidities on the allowable design properties of fire-retardant-treated lumber shall be determined in accordance with ASTM D 5664. The test data developed by ASTM D 5664 shall be used to develop modification factors for use at or near room temperature and at elevated temperatures and humidity in accordance with ASTM D 6841. Each manufacturer shall publish the modification factors for service at temperatures of not less than 80°F (27°C) and for roof framing. The roof framing modification factors shall take into consideration the climatological location.

2303.2.6 Exposure to weather, damp or wet locations.

Where fire-retardant-treated wood is exposed to weather, or damp or wet locations, it shall be identified as "Exterior" to indicate there is no increase in the listed flame spread index as defined in Section 2303.2 when subjected to ASTM D 2898.

2303.2.7 Interior applications. Interior fire-retardant-treated wood shall have moisture content of not over 28 percent when tested in accordance with ASTM D 3201 procedures at 92-percent relative humidity. Interior fire-retardant-treated wood shall be tested in accordance with Section 2303.2. 5.1 or 2303.2. 5.2. Interior fire-retardant-treated wood designated as Type A shall be tested in accordance with the provisions of this section.

2303.2.8 Moisture content. Fire-retardant-treated wood shall be dried to a moisture content of 19 percent or less for lumber and 15 percent or less for wood structural panels before use. For wood kiln dried after treatment (KDAT), the kiln temperatures shall not exceed those used in kiln drying the lumber and plywood submitted for the tests described in Section 2303.2. 5.1 for plywood and 2303.2. 5.2 for lumber.

2303.2.9 Type I and II construction applications. See Section 603.1 for limitations on the use of fire-retardant-treated wood in buildings of Type I or II construction.

2303.3 Hardwood and plywood. Hardwood and decorative plywood shall be manufactured and identified as required in HPVA HP-1.

2303.4 Trusses.

2303.4.1 Design. Wood trusses shall be designed in accordance with the provisions of this code and accepted engineering practice. Members are permitted to be joined by nails, glue, bolts, timber connectors, metal connector plates or other approved framing devices.

2303.4. 1.1 Truss design drawings. The written, graphic and pictorial depiction of each individual truss shall be provided to the building official for approval prior to installation. Truss design drawings shall also be provided with the shipment of trusses delivered to the job site. Truss design drawings shall include, at a minimum, the information specified below:

1. Slope or depth, span and spacing;

2. Location of all joints and support locations;

3. Number of plies if greater than one;

4. Required bearing widths;

5. Design loads as applicable, including;

5.1. Top chord live load;

5.2Top chord dead load;

5.3Bottom chord live load;

5.4Bottom chord dead load;

5.5Additional loads and locations; and

5.6Environmental design criteria and loads (wind, rain, snow, seismic, etc.).

6. Other lateral loads, including drag strut loads;

7. Adjustments to wood member and metal connector plate design value for conditions of use;

8. Maximum reaction force and direction, including maximum uplift reaction forces where applicable;

9. Metal-connector-plate type, size and thickness or gage, and the dimensioned location of each metal connector plate except where symmetrically located relative to the joint interface;

10. Size, species and grade for each wood member;

11. Truss-to-truss connections and truss field assembly requirements;

12. Calculated span-to-deflection ratio and maximum vertical and horizontal deflection for live and total load as applicable;

13. Maximum axial tension and compression forces in the truss members; and

14. Required permanent individual truss member restraint location and the method and details of restraint/bracing to be used in accordance with Section 2303.4. 1.2.

2303.4. 1.2 Permanent individual truss member restraint. Where permanent restraint of truss members is required on the truss design drawings, it shall be accomplished by one of the following methods:

1. Permanent individual truss member restraint/bracing shall be installed using standard industry lateral restraint/bracing details in accordance with generally accepted engineering practice. Locations for lateral restraint shall be identified on the truss design drawing.

2. The trusses shall be designed so that the buckling of any individual truss member is resisted internally by the individual truss through suitable means (i.e., buckling reinforcement by T-reinforcement or L-reinforcement, proprietary reinforcement, etc.). The buckling reinforcement of individual members of the trusses shall be installed as shown on the truss design drawing or on supple-mental truss member buckling reinforcement details provided by the truss designer.

3. A project-specific permanent individual truss member restraint/bracing design shall be permitted to be specified by any registered design professional.

2303.4. 1.3 Trusses spanning 60 feet or greater. The owner shall contract with any qualified registered design professional for the design of the temporary installation restraint/bracing and the permanent individual truss member restraint/bracing for all trusses with clear spans 60 feet (18 288 mm) or greater.

2303.4. 1.4 Truss designer. The individual or organization responsible for the design of trusses.

2303.4. 1.4.1 Truss design drawings. Each individual truss design drawing shall bear the seal and signature of a registered design professional.

Exceptions: Deleted.

2303.4.2 Truss placement diagram. The truss manufacturer shall provide a truss placement diagram that identifies the proposed location for each individually designated truss and references the corresponding truss design drawing. The truss placement diagram shall be provided as part of the truss submittal package, and with the shipment of trusses delivered to the job site. Truss placement diagrams that serve only as a guide for installation and do not deviate from the permit submittal drawings shall not be required to bear the seal or signature of the truss designer.

2303.4.3 Truss submittal package. The truss submittal package provided by the truss manufacturer shall consist of each individual truss design drawing, the truss placement diagram, the permanent individual truss member restraint/bracing method and details and any other structural details germane to the trusses; and, as applicable, the cover/truss index sheet.

2303.4.4 Anchorage. The design for the transfer of loads and anchorage of each truss to the supporting structure is the responsibility of the registered design professional.

2303.4.5 Alterations to trusses. Truss members and components shall not be cut, notched, drilled, spliced or otherwise altered in any way without written concurrence and approval of a registered design professional. Alterations resulting in the addition of loads to any member (e.g., HVAC equipment, piping, additional roofing or insulation, etc.) shall not be permitted without verification that the truss is capable of supporting such additional loading.

2303.4.6 TPI 1 specifications. In addition to Sections 2303.4.1 through 2303.4.5, the design, manufacture and quality assurance of metal-plate-connected wood trusses shall be in accordance with TPI 1. Job-site inspections shall be in compliance with Section 110.4, as applicable.

2303.4.7 Truss quality assurance. Trusses not part of a manufacturing process in accordance with either Section 2303.4.6 or a standard listed in Chapter 35, which provides requirements for quality control done under the supervision of a third-party quality control agency, shall be manufactured in compliance with Sections 1704.2 and 1704.6, as applicable.

2303.5 Test standard for joist hangers and connectors. For the required test standards for joist hangers and connectors, see Section 1716.1.

2303.6 Nails and staples. Nails and staples shall conform to requirements of ASTM F 1667. Nails used for framing and sheathing connections shall have minimum average bending yield strengths as follows: 80 kips per square inch (ksi) (551 MPa) for shank diameters larger than 0.177 inch ( 4.50 mm) but not larger than 0.254 inch ( 6.45 mm), 90 ksi (620 MPa) for shank diameters larger than 0.142 inch ( 3.61 mm) but not larger than 0.177 inch ( 4.50 mm) and 100 ksi (689 MPa) for shank diameters of at least 0.099 inch ( 2.51 mm) but not larger than 0.142 inch ( 3.61 mm).

2303.7 Shrinkage. Consideration shall be given in design to the possible effect of cross-grain dimensional changes considered vertically which may occur in lumber fabricated in a green condition.

SECTION 2304

GENERAL CONSTRUCTION REQUIREMENTS

2304.1 General. The provisions of this section apply to design methods specified in Section 2301.2.

2304.2 Size of structural members. Computations to determine the required sizes of members shall be based on the net dimensions (actual sizes) and not nominal sizes.

2304.3 Wall framing. The framing of exterior and interior walls shall be in accordance with the provisions specified in Section 2308 unless a specific design is furnished.

2304.3.1 Bottom plates. Studs shall have full bearing on a 2-inch-thick(actual 1½-inch, 38 mm) or larger plate or sill having a width at least equal to the width of the studs.

2304.3.2 Framing over openings. Headers, double joists, trusses or other approved assemblies that are of adequate size to transfer loads to the vertical members shall be provided over window and door openings in load-bearing walls and partitions.

2304.3.3 Shrinkage. Wood walls and bearing partitions shall not support more than two floors and a roof unless an analysis shows that shrinkage of the wood framing will not have adverse effects on the structure or any plumbing, electrical or mechanical systems, or other equipment installed therein due to excessive shrinkage or differential movements caused by shrinkage. The analysis shall also show that the roof drainage system and the foregoing systems or equipment will not be adversely affected or, as an alternate, such systems shall be designed to accommodate the differential shrinkage or movements.

2304.4 Floor and roof framing. The framing of wood-joisted floors and wood framed roofs shall be in accordance with the provisions specified in Section 2308 unless a specific design is furnished.

2304.5 Framing around flues and chimneys. Combustible framing shall be a minimum of 2 inches (51 mm), but shall not be less than the distance specified in Sections 2111 and 2113 and the mechanical code, from flues, chimneys and fireplaces, and 6 inches (152 mm) away from flue openings.

2304.6 Wall sheathing. Except as provided for in Section 1405 for weatherboarding or where stucco construction that complies with Section 2510 is installed, enclosed buildings shall be sheathed with one of the materials of the nominal thickness specified in Table 2304.6 or any other approved material of equivalent strength or durability.

TABLE 2304.6

MINIMUM THICKNESS OF WALL SHEATHING

SHEATHING TYPE MINIMUM THICKNESS MAXIMUM WALL STUD SPACING
Wood boards 5/8 inch 24 inches on center
Fiberboard ½ inch 16 inches on center
Wood structural panel In accordance with Tables 2308.9.3(2) and 2308.9.3(3) -
M-S "Exterior Glue" and M-2 "Exterior Glue" Particleboard In accordance with Tables 2306.5 and 2308.9.3(4) -
Gypsum sheathing ½ inch 16 inches on center
Gypsum wallboard ½ inch 24 inches on center
Reinforced cement mortar 1 inch 24 inches on center

For SI: 1 inch = 25.4 mm.

2304.6.1 Wood structural panel sheathing. Where wood structural panel sheathing is used as the exposed finish on the exterior of outside walls, it shall have an exterior exposure durability classification. Where wood structural panel sheathing is used elsewhere, but not as the exposed finish, it shall be of a type manufactured with exterior glue (Exposure 1 or Exterior). Wood structural panel wall sheathing or siding used as structural sheathing shall be capable of resisting wind pressures in accordance with Section 1609. Maximum wind speeds for wood structural panel sheathing used to resist wind pressures shall be in accordance with Table 2304.6.1 for enclosed buildings with a mean roof height not greater than 30 feet (9144 mm), an importance factor (I) of 1.0 and a topographic factor (Kzt) of 1.0.

2304.6.2 Interior paneling. Softwood wood structural panels used for interior paneling shall conform to the provisions of Chapter 8 and shall be installed in accordance with Table 2304.9.1. Panels shall comply with DOC PS 1 or PS 2. Prefinished hardboard paneling shall meet the requirements of CPA/ANSI A 135.5. Hardwood plywood shall conform to HPVA HP-1.

2304.7 Floor and roof sheathing.

2304.7.1 Structural floor sheathing. Structural floor sheathing shall be designed in accordance with the general provisions of this code and the special provisions in this section.

Floor sheathing conforming to the provisions of Table 2304.7(1), 2304.7(2), 2304.7(3) or 2304.7(4) shall be deemed to meet the requirements of this section.

2304.7.2 Structural roof sheathing. Structural roof sheathing shall be designed in accordance with the general provisions of this code and the special provisions in this section.

Roof sheathing conforming to the provisions of Table 2304.7(1), 2304.7(2), 2304.7(3) or 2304.7(5) shall be deemed to meet the requirements of this section. Wood structural panel roof sheathing shall be bonded by exterior glue.

TABLE 2304.6.1

MAXIMUM BASIC WIND SPEED (mph) (3-SECOND GUST) PERMITTED FOR WOOD STRUCTURAL PANEL WALL SHEATHING USED TO RESIST WIND PRESSURESa, b, c

MINIMUM NAIL MINIMUMWOODSTRUCTURALPANEL SPANRATING MINIMUM NOMINALPANEL THICKNESS(inches) MAXIMUMWALLSTUDSPACING(inches) PANEL NAIL SPACING MAXIMUM WIND SPEED (MPH)
Size Penetration (inches) Edges(incheso.c.) Field(incheso.c.) Wind exposure category
B C D
6d common( 2.0 " * 0.113 " ) 1.5 24/0 3/8 16 6 12 110 90 85
24/16 7/16 16 6 12 110 100 90
6 150 125 110
8d common( 2.5 " * 0.131 ") 1.75 24/16 7/16 16 6 12 130 110 105
6 150 125 110
24 6 12 110 90 85
6 110 90 85

For SI: 1 inch = 25.4 mm, 1 mile per hour = 0.447 m/s.

a. Panel strength axis shall be parallel or perpendicular to supports. Three-ply plywood sheathing with studs spaced more than 16 inches on center shall be applied with panel strength axis perpendicular to supports.

b. The table is based on wind pressures acting toward and away from building surfaces in accordance with Section 6.4. 2.2 of ASCE 7. Lateral requirements shall be in accordance with Section 2305 or 2308.

c. Wood structural panels with span ratings of wall-16 or wall-24 shall be permitted as an alternative to panels with a 24/0 span rating. Plywood siding rated 16 o.c. or 24 o.c. shall be permitted as an alternative to panels with a 24/16 span rating. Wall-16 and plywood siding 16 o.c. shall be used with studs spaced a maximum of 16 inches o.c.

TABLE 2304.7(1)

ALLOWABLE SPANS FOR LUMBER FLOOR AND ROOF SHEATHINGa, b

SPAN (inches) MINIMUM NET THICKNESS (inches) OF LUMBER PLACED
  Perpendicular to supports Diagonally to supports
Surfaced dryc Surfaced unseasoned Surfaced dryc Surfaced unseasoned
Floors
24 3/4 25/32 3/4 25/32
16 5/8 11/16 5/8 11/16
Roofs
24 5/8 11/16 3/4 25/32

For SI: 1 inch = 25.4 mm.

a. Installation details shall conform to Sections 2304.7.1 and 2304.7.2 for floor and roof sheathing, respectively.

b. Floor or roof sheathing conforming with this table shall be deemed to meet the design criteria of Section 2304.7.

c. Maximum 19-percent moisture content.

TABLE 2304.7(2)

SHEATHING LUMBER, MINIMUM GRADE REQUIREMENTS: BOARD GRADE

SOLID FLOOR OR ROOF SHEATHING SPACED ROOF SHEATHING GRADING RULES
Utility Standard NLGA, WCLIB, WWPA
4 common or utility 3 common or standard NLGA, WCLIB, WWPA, NSLB or NELMA
No. 3 No. 2 SPIB
Merchantable Construction common RIS

TABLE 2304.7(3)

ALLOWABLE SPANS AND LOADS FOR WOOD STRUCTURAL PANEL

SHEATHING AND

SINGLE-FLOOR GRADES CONTINUOUS OVER TWO OR MORE

SPANS WITH

STRENGTH AXIS PERPENDICULAR TO SUPPORTSa, b

SHEATHING GRADES ROOFc FLOORd
Panel span ratingroof/floor span Panel thickness (inches) Maximum span (inches) Loade (psf) Maximum span (inches)
With edgesupportf Without edge support Total load Live load
16/0 3/8 16 16 40 30 0
20/0 3/8 20 20 40 30 0
24/0 3/8, 7/16, 1/2 24 20g 40 30 0
24/16 7/16, 1/2 24 24 50 40 16
32/16 15/32, 1/2, 5/8 32 28 40 30 16h
40/20 19/32, 5/8, 3/4, 7/8 40 32 40 30 20h,i
48/24 23/32, 3/4, 7/8 48 36 45 35 24
54/32 7/8, 1 54 40 45 35 32
60/32 7/8, 11/8 60 48 45 35 32
SINGLE FLOOR GRADES ROOFc FLOORd
Panel span rating Panel thickness (inches) Maximum span (inches) Loade(psf) Maximum span (inches)
With edgesupportf Withoutedge support Total load Live load
16 o.c. 1/2, 19/32, 5/8 24 24 50 40 16h
20 o.c. 19/32, 5/8, 3/4 32 32 40 30 20h,i
24 o.c. 23/32, 3/4 48 36 35 25 24
32 o.c. 7/8, 1 48 40 50 40 32
48 o.c. 13/32, 11/8 60 48 50 40 48

For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kN/m2 .

a. Applies to panels 24 inches or wider.

b. Floor and roof sheathing conforming with this table shall be deemed to meet the design criteria ofSection 2304.7.

c. Uniform load deflection limitations 1/180 of span under live load plus dead load, 1/240 under live load only.

d. Panel edges shall have approved tongue-and-groove joints or shall be supported with blocking unless 1/4 -inch minimum thickness underlayment or 1½ inches of approved cellular or lightweight concrete is placed over the subfloor, or finish floor is 3/4 -inch wood strip. Allowable uniform load based on deflection of 1/360 of span is 100 pounds per square foot except the span rating of 48 inches on center is based on a total load of 65 pounds per square foot.

e. Allowable load at maximum span.

f. Tongue-and-groove edges, panel edge clips (one midway between each support, except two equally spaced between supports 48 inches on center), lumber blocking or other. Only lumber blocking shall satisfy blocked diaphragm requirements.

g. For ½ -inch panel, maximum span shall be 24 inches.

h. Span is permitted to be 24 inches on center where 3/4 -inch wood strip flooring is installed at right angles to joist.

i. Span is permitted to be 24 inches on center for floors where 1 ½ inches of cellular or lightweight concrete is applied over the panels.

TABLE 2304.7(4)

ALLOWABLE SPAN FOR WOOD STRUCTURAL PANEL

COMBINATION SUBFLOOR-UNDERLAYMENT (SINGLE FLOOR)a, b

(Panels Continuous Over Two or More Spans and Strength Axis

Perpendicular to Supports)

IDENTIFICATION MAXIMUM SPACING OF JOISTS (inches)
16 20 24 32 48
Species groupc Thickness (inches)
1 1/2 5/8 3/4 - -
2, 3 5/8 3/4 7/8 - -
4 3/4 7/8 1 - -
Single floor span ratingd 16 o.c. 20 o.c. 24 o.c. 32 o.c. 48 o.c.

For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kN/m2 .

a. Spans limited to value shown because of possible effects of concentrated loads. Allowable uniform loads based on deflection of 1/360 of span is 100 pounds per square foot except allowable total uniform load for 11/8 -inch wood structural panels over joists spaced 48 inches on center is 65 pounds per square foot. Panel edges shall have approved tongue-and-groove joints or shall be supported with blocking, unless 1/4 -inch minimum thickness underlayment or 1½ inches of approved cellular or lightweight concrete is placed over the subfloor, or finish floor is 3/4 -inch wood strip.

b. Floor panels conforming with this table shall be deemed to meet the design criteria of Section 2304.7.

c. Applicable to all grades of sanded exterior-type plywood. See DOC PS 1 for plywood species groups.

d. Applicable to Underlayment grade, C-C (Plugged) plywood, and Single Floor grade wood structural panels.

TABLE 2304.7(5)

ALLOWABLE LOAD (PSF) FOR WOOD STRUCTURAL PANEL ROOF

SHEATHING CONTINUOUS OVER TWO OR MORE SPANS AND

STRENGTH AXIS PARALLEL TO SUPPORTS

(Plywood Structural Panels Are Five-Ply, Five-Layer Unless Otherwise

Noted)a, b

PANEL GRADE THICKNESS (inch) MAXIMUM SPAN (inches) LOAD AT MAXIMUM SPAN (psf)
Live Total
Structural I sheathing 7/16 24 20 30
15/32 24 35c 45c
1/2 24 40c 50c
19/32, 5/8 24 70 80
23/32, 3/4 24 90 100
Sheathing, other gradescovered in DOC PS 1 orDOC PS 2 7/16 16 40 50
15/32 24 20 25
1/2 24 25 30
19/32 24 40c 50c
5/8 24 45c 55c
23/32, 3/4 24 60c 65c

For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kN/m2 .

a. Roof sheathing conforming with this table shall be deemed to meet the design criteria ofSection 2304.7.

b. Uniform load deflection limitations 1/180 of span under live load plus dead load, 1/240 under live load only. Edges shall be blocked with lumber or other approved type of edge supports.

c. For composite and four-ply plywood structural panel, load shall be reduced by 15 pounds per square foot.

2304.8 Lumber decking.

2304.8.1 General. Lumber decking shall be designed and installed in accordance with the general provisions of this code and Section 2304.8. Each piece shall be square end trimmed. When random lengths are furnished, each piece shall be square end trimmed across the face so that at least 90 percent of the pieces are within 0.5 degrees ( 0.00873 rad) of square. The ends of the pieces shall be permitted to be beveled up to 2 degrees ( 0.0349 rad) from the vertical with the exposed face of the piece slightly longer than the opposite face of the piece. Tongue-and-groove decking shall be installed with the tongues up on sloped or pitched roofs with pattern faces down.

2304.8.2 Layup patterns. Lumber decking is permitted to be laid up following one of five standard patterns as defined in Sections 2304.8. 2.1 through 2304.8. 2.5. Other patterns are permitted to be used provided they are substantiated through engineering analysis.

2304.8. 2.1 Simple span pattern. All pieces shall be supported on their ends (i.e., by two supports).

2304.8. 2.2 Two-span continuous pattern. All pieces shall be supported by three supports, and all end joints shall occur in line on alternating supports. Supporting members shall be designed to accommodate the load redistribution caused by this pattern.

2304.8. 2.3 Combination simple and two-span continuous pattern.

Courses in end spans shall be alternating simple-span pattern and two-span continuous pattern. End joints shall be staggered in adjacent courses and shall bear on supports.

2304.8. 2.4 Cantilevered pieces intermixed pattern. The decking shall extend across a minimum of three spans. Pieces in each starter course and every third course shall be simple span pattern. Pieces in other courses shall be cantilevered over the supports with end joints at alternating quarter or third points of the spans. Each piece shall bear on at least one support.

2304.8. 2.5 Controlled random pattern. The decking shall extend across a minimum of three spans. End joints of pieces within 6 inches (152 mm) of the end joints of the adjacent pieces in either direction shall be separated by at least two intervening courses. In the end bays, each piece shall bear on at least one support. Where an end joint occurs in an end bay, the next piece in the same course shall continue over the first inner support for at least 24 inches (610 mm). The details of the controlled random pattern shall be as specified for each decking material in Section 2304.8. 3.3, 2304.8. 4.3 or 2304.8. 5.3.

Decking that cantilevers beyond a support for a horizontal distance greater than 18 inches (457 mm), 24 inches (610 mm) or 36 inches (914 mm) for 2-inch (51 mm), 3-inch (76 mm) and 4-inch (102 mm) nominal thickness decking, respectively, shall comply with the following:

1. The maximum cantilevered length shall be 30 percent of the length of the first adjacent interior span.

2. A structural fascia shall be fastened to each decking piece to maintain a continuous, straight line.

3. There shall be no end joints in the decking between the cantilevered end of the decking and the center-line of the first adjacent interior span.

2304.8.3 Mechanically laminated decking.

2304.8. 3.1 General. Mechanically laminated decking consists of square-edged dimension lumber laminations set on edge and nailed to the adjacent pieces and to the supports.

2304.8. 3.2 Nailing. The length of nails connecting laminations shall not be less than two and one-half times the net thickness of each lamination. Where decking supports are 48 inches (1219 mm) on center (o.c.) or less, side nails shall be installed not more than 30 inches (762 mm) o.c. alternating between top and bottom edges, and staggered one-third of the spacing in adjacent laminations. Where supports are spaced more than 48 inches (1219 mm) o.c., side nails shall be installed not more than 18 inches (457 mm) o.c. alternating between top and bottom edges and staggered one-third of the spacing in adjacent laminations. Two side nails shall be installed at each end of butt-jointed pieces.

Laminations shall be toenailed to supports with 20d or larger common nails. Where the supports are 48 inches (1219 mm) o.c. or less, alternate laminations shall be toenailed to alternate supports; where supports are spaced more than 48 inches (1219 mm) o.c., alternate laminations shall be toenailed to every support.

2304.8. 3.3 Controlled random pattern. There shall be a minimum distance of 24 inches (610 mm) between end joints in adjacent courses. The pieces in the first and second courses shall bear on at least two supports with end joints in these two courses occurring on alternate supports. A maximum of seven intervening courses shall be permitted before this pattern is repeated.

2304.8.4 Two-inch sawn tongue-and-groove decking.

2304.8. 4.1 General. Two-inch (51 mm) decking shall have a maximum moisture content of 15 percent. Decking shall be machined with a single tongue-and-groove pattern. Each decking piece shall be nailed to each support.

2304.8. 4.2 Nailing. Each piece of decking shall be toenailed at each support with one 16d common nail through the tongue and face-nailed with one 16d common nail.

2304.8. 4.3 Controlled random pattern. There shall be a minimum distance of 24 inches (610 mm) between end joints in adjacent courses. The pieces in the first and second courses shall bear on at least two supports with end joints in these two courses occurring on alternate supports. A maximum of seven intervening courses shall be permitted before this pattern is repeated.

2304.8.5 Three-and 4-inch sawn tongue-and-groove decking.

2304.8. 5.1 General. Three-inch (76 mm) and 4-inch (102 mm) decking shall have a maximum moisture content of 19 percent. Decking shall be machined with a double tongue-and-groove pattern. Decking pieces shall be interconnected and nailed to the supports.

2304.8. 5.2 Nailing. Each piece shall be toenailed at each support with one 40d common nail and face-nailed with one 60d common nail. Courses shall be spiked to each other with 8-inch (203 mm) spikes at maximum intervals of 30 inches (762 mm) through predrilled edge holes penetrating to a depth of approximately 4 inches (102 mm). One spike shall be installed at a distance not exceeding 10 inches (254 mm) from the end of each piece.

2304.8. 5.3 Controlled random pattern. There shall be a minimum distance of 48 inches (1219 mm) between end joints in adjacent courses. Pieces not bearing on a support are permitted to be located in interior bays provided the adjacent pieces in the same course continue over the support for at least 24 inches (610 mm). This condition shall not occur more than once in every six courses in each interior bay.

2304.9 Connections and fasteners.

2304.9.1 Fastener requirements. Connections for wood members shall be designed in accordance with the appropriate methodology in Section 2301.2. The number and size of fasteners connecting wood members shall not be less than that set forth in Table 2304.9.1.

2304.9.2 Sheathing fasteners. Sheathing nails or other approved sheathing connectors shall be driven so that their head or crown is flush with the surface of the sheathing.

2304.9.3 Joist hangers and framing anchors. Connections depending on joist hangers or framing anchors, ties and other mechanical fastenings not otherwise covered are permitted where approved. The vertical load-bearing capacity, torsional moment capacity and deflection characteristics of joist hangers shall be determined in accordance with Section 1716.1.

2304.9.4 Other fasteners. Clips, staples, glues and other approved methods of fastening are permitted where approved.

2304.9.5 Fasteners and connectors in contact with preservative-treated and fire-retardant-treated wood. Fasteners and connectors in contact with preservative-treated and fire-retardant-treated wood shall be in accordance with Sections 2304.9. 5.1 through 2304.9. 5.4. The coating weights for zinc-coated fasteners shall be in accordance with ASTM A 153.

2304.9. 5.1 Fasteners and connectors for preservative-treated wood.

Fasteners in contact with preservative-treated wood shall be of hot-dipped zinc-coated galvanized steel, stainless steel, silicon bronze or copper. Fasteners other than nails, timber rivets, wood screws and lag screws shall be permitted to be of mechanically deposited zinc-coated steel with coating weights in accordance with ASTM B 695, Class 55 minimum. Connectors that are used in exterior applications and in contact with preservative-treated wood shall have coating types and weights in accordance with the treated wood or connector manufacturer's recommendations. In the absence of manufacturer's recommendations, a minimum of ASTM A 653, type G185 zinc-coated galvanized steel, or equivalent, shall be used.

Exception: Plain carbon steel fasteners in SBX/DOT and zinc borate preservative-treated wood in an interior, dry environment shall be permitted.

2304.9. 5.2 Fastenings for wood foundations. Fastenings for wood foundations shall be as required in AF&PA PWF.

2304.9. 5.3 Fasteners for fire-retardant-treated wood used in exterior applications or wet or damp locations. Fasteners for fire-retardant-treated wood used in exterior applications or wet or damp locations shall be of hot-dipped zinc-coated galvanized steel, stainless steel, silicon bronze or copper. Fasteners other than nails, timber rivets, wood screws and lag screws shall be permitted to be of mechanically deposited zinc-coated steel with coating weights in accordance with ASTM B 695, Class 55 minimum.

2304.9. 5.4 Fasteners for fire-retardant-treated wood used in interior applications. Fasteners for fire-retardant-treated wood used in interior locations shall be in accordance with the manufacturer's recommendations. In the absence of manufacturer's recommendations, Section 2304.9. 5.3 shall apply.

2304.9.6 Load path. Where wall framing members are not continuous from foundation sill to roof, the members shall be secured to ensure a continuous load path. Where required, sheet metal clamps, ties or clips shall be formed of galvanized steel or other approved corrosion-resistant material not less than 0.040 inch ( 1.01 mm) nominal thickness.

2304.9.7 Framing requirements. Wood columns and posts shall be framed to provide full end bearing. Alternatively, column-and-post end connections shall be designed to resist the full compressive loads, neglecting end-bearing capacity. Column-and-post end connections shall be fastened to resist lateral and net induced uplift forces.

2304.10 Heavy timber construction.

2304.10.1 Columns. Columns shall be continuous or superimposed throughout all stories by means of reinforced concrete or metal caps with brackets, or shall be connected by properly designed steel or iron caps, with pintles and base plates, or by timber splice plates affixed to the columns by metal connectors housed within the contact faces, or by other approved methods.

2304.10. 1.1 Column connections. Girders and beams shall be closely fitted around columns and adjoining ends shall be cross tied to each other, or intertied by caps or ties, to transfer horizontal loads across joints. Wood bolsters shall not be placed on tops of columns unless the columns support roof loads only.

TABLE 2304.9.1

FASTENING SCHEDULE

CONNECTION FASTENINGa, m LOCATION
1. Joist to sill or girder 3 - 8d common (2 ½" x 0.131 ") toenail
3 - 3" x 0.131 " nails
3 - 3" 14 gage staples
2. Bridging to joist 2 - 8d common (2 ½" x 0.131 ") toenail each end
2 - 3" x 0.131 " nails
2 - 3" 14 gage staples
3. 1" x 6" subfloor or less to each joist 2 - 8d common (2 ½" x 0.131 ") face nail
4. Wider than 1" x 6" subfloor to each joist 3 - 8d common (2 ½" x 0.131 ") face nail
5. 2" subfloor to joist or girder 2 - 16d common (3 ½" x 0.162 ") blind and face nail
6. Sole plate to joist or blocking Sole plate to joist or blocking at braced wall panel 16d (3 ½" * 0.135 ") at 16"o.c. typical face nail braced wall panels
3" * 0.131 " nails at 8"o.c.
3" 14 gage staples at 12" o.c.
3 - 16d (3 ½" * 0.135 ") at 16" o.c.
4 - 3" * 0.131 " nails at 16"o.c.
4 - 3" 14 gage staples at 16"o.c.
7. Top plate to stud 2 - 16d common (3 ½" * 0.162 " ) end nail
3 - 3" * 0.131 " nails
3 - 3" 14 gage staples
8. Stud to sole plate 4 - 8d common (2 ½" * 0.131 ") toenail end nail
4 - 3" * 0.131 " nails
3 - 3" 14 gage staples
2 - 16d common (3 ½" * 0.162 ")
3 - 3" * 0.131 " nails
3 - 3" 14 gage staples
9. Double studs 16d (3 ½" * 0.135 ") at 24"o.c. face nail
3" * 0.131 " nail at 8" o.c.
3" 14 gage staple at 8" o.c.
10. Double top plates Double top plates 16d (3 ½" * 0.135 ") at 16"o.c. typical face nail lap splice
3" * 0.131 " nail at 12" o.c.
3" 14 gage staple at 12"o.c.
8 - 16d common (3 ½" * 0.162 " )
12 - 3" * 0.131 " nails
12 - 3" 14 gage staples
11. Blocking between joists or rafters to top plate 3 - 8d common (2 ½" * 0.131 ") toenail
3 - 3" * 0.131 " nails
3 - 3" 14 gage staples
12. Rim joist to top plate 8d (2 ½" * 0.131 ") at at 16" o.c. toenail
3" * 0.131 " nail at 6" o.c.
3" 14 gage staple at 6" o.c.
13. Top plates, laps and intersections 2 - 16d common (3 ½" * 0.162 ") face nail
3 - 3" * 0.131 " nails
3 - 3" 14 gage staples
14. Continuous header, two pieces 16d common (3 ½" * 0.162 ") 16 o.c. along edge
15. Ceiling joists to plate 3 - 8d common (2 ½" * 0.131 ") toenail
5 - 3" * 0.131 " nails
5 - 3"14 gage staples
16. Continuous header to stud 4 - 8d common (2 ½" x 0.131 ") toenail
17. Ceiling joists, laps over partitions (see Section 2308.10. 4.1, Table 2308.10. 4.1 ) 3 - 16d common (3 ½" x 0.162 " ) minimum, Table 2308.10. 4.1 face nail
4 - 3" x 0.131 " nails
4 - 3" 14 gage staples
18. Ceiling joists to parallel rafters (see Section 2308.10. 4.1, Table 2308.10. 4.1 ) 3 - 16d common (3 ½" x 0.162 ") minimum, Table 2308.10. 4.1 face nail
4 - 3" x 0.131 " nails
4 - 3" 14 gage staples
19. Rafter to plate (see Section 2308.10.1, Table 2308.10.1) 3 - 8d common (2 ½" x 0.131 ") toenail
3 - 3" x 0.131 " nails
3 - 3" 14 gage staples
20.1 " diagonal brace to each stud and plate 2 - 8d common (2 ½" 0.131 ") toenail
2 - 3" * 0.131 " nails
3 - 3" 14 gage staples
21. 1" * 8" sheathing to each bearing 3 - 8d common (2 ½" * 0.131 ") face nail
22. Wider than 1" * 8" sheathing to each bearing 3 - 8d common (2 ½" * 0.131 ") face nail
23. Built-up corner studs 16d common (3 ½" * 0.162 ") 24" o.c.
3" * 0.131 " nails 16" o.c.
3" 14 gage staples 16" o.c.
24. Built-up girder and beams 20d common (4" * 0.192 " ) 32" o.c. face nail at top and bottom staggered on opposite sides face nail at ends and at each splice
3" * 0.131 " nail at 24"o.c.
3" 14 gage staple at 24" o.c.
2 - 20d common (4" * 0.192 ")
3 - 3" * 0.131 " nails
3 - 3" 14 gage staples
25. 2" planks 16d common (3 ½" * 0.162 ") at each bearing
26. Collar tie to rafter 3 - 10d common (3" * 0.148 ") face nail
4 - 3" * 0.131 " nails
4 - 3" 14 gage staples
27. Jack rafter to hip 3 - 10d common (3" * 0.148 ") toenail face nail
4 - 3" * 0.131 " nails
4 - 3" 14 gage staples
2 - 16d common (3 ½" * 0.162 ")
3 - 3" * 0.131 " nails
3 - 3" 14 gage staples
28. Roof rafter to 2-by ridge beam 2 - 16d common (3 ½" * 0.162 ") toenail face nail
3 - 3" * 0.131 " nails
3 - 3" 14 gage staples
2 -16d common (3 ½" * 0.162 ")
3 - 3" * 0.131 " nails
3 - 3" 14 gage staples
29. Joist to band joist 3 - 16d common (3 ½" * 0.162 ") face nail
4 - 3" * 0.131 " nails
4 - 3" 14 gage staples
30. Ledger strip 3 - 16d common (3 ½" * 0.162 ") face nail at each joist
4 - 3" * 0.131 " nails
4 - 3" 14 gage staples
31. Wood structural panels andparticleboardb Subfloor, roof and wall sheathing (to framing)Single floor (combination subfloor-underlayment to framing) ½" and less 6dc, 1  
2 3/8" * 0.113 " nailn
1 3/4" 16 gageo
19/32" to 3/4" 8ddor 6de
2 3/8" * 0.113 " nailp
2" 16 gagep
7/8 " to 1" 8dc
1 1/8" to 1 1/4" 10dd or 8de
3/4" and less 6de
7/8 " to 1" 8de
11/8" to 1 1/4" 10dd or 8de
32. Panel siding (to framing) ½" or less 6df  
5/8" 8df
33. Fiberboard sheathingg ½" No. 11 gage roofing nailh  
6d common nail (2" * 0.113 ")
No. 16 gage staplei
25/32 " No. 11 gage roofing nailh
8d common nail (2 ½" * 0.131 ")
No. 16 gage staplei
34. Interior paneling 1/4" 4dj  
3/8" 6dk

For SI: 1 inch = 25.4 mm.

a. Common or box nails are permitted to be used except where otherwise stated.

b. Nails spaced at 6 inches on center at edges, 12 inches at intermediate supports except 6 inches at supports where spans are 48 inches or more. For nailing of wood structural panel and particleboard diaphragms and shear walls, refer to Section 2305. Nails for wall sheathing are permitted to be common, box or casing.

c. Common or deformed shank (6d - 2" * 0.113 "; 8d - 2 ½" * 0.131 "; 10d - 3" * 0.148 ").

d. Common (6d - 2" * 0.113 "; 8d - 2 ½" * 0.131 "; 10d - 3" * 0.148 ").

e. Deformed shank (6d - 2" * 0.113 "; 8d - 2 ½" * 0.131 "; 10d - 3" * 0.148 ").

f. Corrosion-resistant siding (6d - 1 7/8" * 0.106 "; 8d - 2 3 /8"*0.128 ") or casing (6d - 2" * 0.099 "; 8d - 2 ½" * 0.113 ") nail.

g. Fasteners spaced 3 inches on center at exterior edges and 6 inches on center at intermediate supports, when used as structural sheathing. Spacing shall be 6 inches on center on the edges and 12 inches on center at intermediate supports for nonstructural applications.

h. Corrosion-resistant roofing nails with 7/16-inch-diameter head and 1½ -inch length for ½ -inch sheathing and 13/4 -inch length for 25 /32-inch sheathing.

i. Corrosion-resistant staples with nominal 7/16-inch crown or 1-inch crown and 11/4 -inch length for ½ -inch sheathing and 1½ -inch length for 25/32-inch sheathing. Panel supports at 16 inches (20 inches if strength axis in the long direction of the panel, unless otherwise marked).

j. Casing (1 ½" * 0.080 ") or finish (1 ½" * 0.072 ") nails spaced 6 inches on panel edges, 12 inches at intermediate supports.

k. Panel supports at 24 inches. Casing or finish nails spaced 6 inches on panel edges, 12 inches at intermediate supports.

l. For roof sheathing applications, 8d nails (2 ½" * 0.113 ") are the minimum required for wood structural panels.

m. Staples shall have a minimum crown width of 7/16 inch.

n. For roof sheathing applications, fasteners spaced 4 inches on center at edges, 8 inches at intermediate supports.

o. Fasteners spaced 4 inches on center at edges, 8 inches at intermediate supports for subfloor and wall sheathing and 3 inches on center at edges, 6 inches at intermediate supports for roof sheathing.

p. Fasteners spaced 4 inches on center at edges, 8 inches at intermediate supports.

2304.10.2 Floor framing. Approved wall plate boxes or hangers shall be provided where wood beams, girders or trusses rest on masonry or concrete walls. Where intermediate beams are used to support a floor, they shall rest on top of girders, or shall be supported by ledgers or blocks securely fastened to the sides of the girders, or they shall be supported by an approved metal hanger into which the ends of the beams shall be closely fitted.

2304.10.3 Roof framing. Every roof girder and at least every alternate roof beam shall be anchored to its supporting member; and every monitor and every sawtooth construction shall be anchored to the main roof construction. Such anchors shall consist of steel or iron bolts of sufficient strength to resist vertical uplift of the roof.

2304.10.4 Floor decks. Floor decks and covering shall not extend closer than ½ inch ( 12.7 mm) to walls. Such ½ -inch ( 12.7 mm) spaces shall be covered by a molding fastened to the wall either above or below the floor and arranged such that the molding will not obstruct the expansion or contraction movements of the floor. Corbeling of masonry walls under floors is permitted in place of such molding.

2304.10.5 Roof decks. Where supported by a wall, roof decks shall be anchored to walls to resist uplift forces determined in accordance with Chapter 16. Such anchors shall consist of steel or iron bolts of sufficient strength to resist vertical uplift of the roof.

2304.11 Protection against decay and termites.

2304.11.1 General. Where required by this section, protection from decay and termites shall be provided by the use of naturally durable or preservative-treated wood.

2304.11.2 Wood used above ground. Wood used above ground in the locations specified in Sections 2304.11. 2.1 through 2304.11. 2.7, 2304.11.3 and 2304.11.5 shall be naturally durable wood or preservative-treated wood using water-borne preservatives, in accordance with AWPA U1 (Commodity Specifications A or F) for above-ground use.

2304.11. 2.1 Joists, girders and subfloor. Where wood joists or the bottom of a wood structural floor without joists are closer than 18 inches (457 mm), or wood girders are closer than 12 inches (305 mm) to the exposed ground in crawl spaces or unexcavated areas located within the perimeter of the building foundation, the floor construction (including posts, girders, joists and subfloor) shall be of naturally durable or preservative-treated wood.

2304.11. 2.2 Wood supported by exterior foundation walls. Wood framing members, including wood sheathing, that rest on exterior foundation walls and are less than 8 inches (203 mm) from exposed earth shall be of naturally durable or preservative-treated wood.

2304.11. 2.3 Exterior walls below grade. Wood framing members and furring strips attached directly to the interior of exterior masonry or concrete walls below grade shall be of approved naturally durable or preservative-treated wood.

2304.11. 2.4 Sleepers and sills. Sleepers and sills on a concrete or masonry slab that is in direct contact with earth shall be of naturally durable or preservative-treated wood.

2304.11. 2.5 Girder ends. The ends of wood girders entering exterior masonry or concrete walls shall be provided with a ½ -inch ( 12.7 mm) air space on top, sides and end, unless naturally durable or preservative-treated wood is used.

2304.11. 2.6 Wood siding. Clearance between wood siding and earth on the exterior of a building shall not be less than 6 inches (152 mm) or less than 2 inches (51 mm) vertical from concrete steps, porch slabs, patio slabs and similar horizontal surfaces exposed to the weather except where siding, sheathing and wall framing are of naturally durable or preservative-treated wood.

2304.11. 2.7 Posts or columns. Posts or columns supporting permanent structures and supported by a concrete or masonry slab or footing that is in direct contact with the earth shall be of naturally durable or preservative-treated wood.

Exceptions:

1. Posts or columns that are either exposed to the weather or located in basements or cellars, supported by concrete piers or metal pedestals projected at least 1 inch (25 mm) above the slab or deck and 6 inches (152 mm) above exposed earth, and are separated therefrom by an impervious moisture barrier.

2. Posts or columns in enclosed crawl spaces or unexcavated areas located within the periphery of the building, supported by a concrete pier or metal pedestal at a height greater than 8 inches (203 mm) from exposed ground, and are separated therefrom by an impervious moisture barrier.

2304.11.3 Laminated timbers. The portions of glued-laminated timbers that form the structural supports of a building or other structure and are exposed to weather and not fully protected from moisture by a roof, eave or similar covering shall be pressure treated with preservative or be manufactured from naturally durable or preservative-treated wood.

2304.11.4 Wood in contact with the ground or fresh water.

Wood used in contact with the ground (exposed earth) in the locations specified in Sections 2304.11. 4.1 and 2304.11. 4.2 shall be naturally durable (species for both decay and termite resistance) or preservative treated using water-borne preservatives in accordance with AWPA U1 (Commodity Specifications A or F) for soil or fresh water use.

Exception: Untreated wood is permitted where such wood is continuously and entirely below the groundwater level or submerged in fresh water.

2304.11. 4.1 Posts or columns. Posts and columns supporting permanent structures that are embedded in concrete that is in direct contact with the earth, embedded in concrete that is exposed to the weather or in direct contact with the earth shall be of preservative-treated wood.

2304.11. 4.2 Wood structural members. Wood structural members that support moisture-permeable floors or roofs that are exposed to the weather, such as concrete or masonry slabs, shall be of naturally durable or preservative-treated wood unless separated from such floors or roofs by an impervious moisture barrier.

2304.11.5 Supporting member for permanent appurtenances. Naturally durable or preservative-treated wood shall be utilized for those portions of wood members that form the structural supports of buildings, balconies, porches or similar permanent building appurtenances where such members are exposed to the weather without adequate protection from a roof, eave, overhang or other covering to prevent moisture or water accumulation on the surface or at joints between members.

Exception: When a building is located in a geographical region where experience has demonstrated that climatic conditions preclude the need to use durable materials where the structure is exposed to the weather.

2304.11.6 Termite protection. In geographical areas where hazard of termite damage is known to be very heavy, wood floor framing shall be of naturally durable species (termite resistant) or preservative treated in accordance with AWPA U1 for the species, product preservative and end use or provided with approved methods of termite protection.

2304.11.7 Wood used in retaining walls and cribs. Wood installed in retaining or crib walls shall be preservative treated in accordance with AWPA U1 (Commodity Specifications A or F) for soil and fresh water use.

2304.11.8 Attic ventilation. For attic ventilation, see Section 1203.2.

2304.11.9 Under-floor ventilation (crawl space). For under-floor ventilation (crawl space), see Section 1203.3.

2304.12 Long-term loading. Wood members supporting concrete, masonry or similar materials shall be checked for the effects of long-term loading using the provisions of the AF&PA NDS. The total deflection, including the effects of long-term loading, shall be limited in accordance with Section 1604.3.1 for these supported materials.

Exception: Horizontal wood members supporting masonry or concrete nonstructural floor or roof surfacing not more than 4 inches (102 mm) thick need not be checked for long-term loading.

SECTION 2305

GENERAL DESIGN REQUIREMENTS FOR LATERAL-FORCE-

RESISTING SYSTEMS

2305.1 General. Structures using wood shear walls and diaphragms to resist wind, seismic and other lateral loads shall be designed and constructed in accordance with AF&PA SDPWS and the provisions of Sections 2305, 2306 and 2307.

2305.1.1 Openings in shear panels. Openings in shear panels that materially affect their strength shall be detailed on the plans, and shall have their edges adequately reinforced to transfer all shearing stresses.

2305.2 Diaphragm deflection. The deflection ( [DELTA] ) of a blocked wood structural panel diaphragm uniformly fastened throughout with staples is permitted to be calculated by using the following equation. If not uniformly fastened, the constant 0.188 (For SI: 1/1627) in the third term shall be modified accordingly.

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-1.png

where:

A = Area of chord cross section, in square inches (mm2).

b = Diaphragm width, in feet (mm).

E = Elastic modulus of chords, in pounds per square inch (N/mm2).

en= Staple deformation, in inches (mm) [see Table 2305.2(1) ].

Gt = Panel rigidity through the thickness, in pounds per inch (N/mm) of panel width or depth [see Table 2305.2(2) ].

L = Diaphragm length, in feet (mm).

v = Maximum shear due to design loads in the direction under consideration, in pounds per linear foot (plf) (N/mm).

[DELTA]= The calculated deflection, in inches (mm).

[SIGMA]([DELTA]cX)= Sum of individual chord-splice slip values on both sides of the diaphragm, each multiplied by its distance to the nearest support.

TABLE 2305.2(1)

en VALUES (inches) FOR USE IN CALCULATING DIAPHRAGM AND

SHEAR WALL DEFLECTION DUE TO FASTENER SLIP (Structural I)a, c

LOAD PERFASTENERb(pounds) FASTENER DESIGNATIONS
14-Ga staple x 2 inches long
60 0.011
80 0.018
100 0.028
120 0.04
140 0.053
160 0.068

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 4.448 N.

a. Increase en values 20 percent for plywood grades other than Structural I.

b. Load per fastener = maximum shear per foot divided by the number of fasteners per foot at interior panel edges.

c. Decrease en values 50 percent for seasoned lumber (moisture content <19 percent).

2305.3 Shear wall deflection. The deflection ([DELTA] ) of a blocked wood structural panel shear wall uniformly fastened throughout with staples is permitted to be calculated by the use of the following equation:

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-2.png

where:

A = Area of boundary element cross section in square inches (mm2) (vertical member at shear wall boundary).

b = Wall width, in feet (mm).

da = Vertical elongation of overturning anchorage (including fastener slip, device elongation, anchor rod elongation, etc.) at the design shear load (v).

E = Elastic modulus of boundary element (vertical member at shear wall boundary), in pounds per square inch (N/mm2).

en= Staple deformation, in inches (mm) [see Table 2305.2(1) ].

Gt= Panel rigidity through the thickness, in pounds per inch (N/mm) of panel width or depth [see Table 2305.2(2) ] .

h = Wall height, in feet (mm).

v = Maximum shear due to design loads at the top of the wall, in pounds per linear foot (N/mm).

[DELTA] = The calculated deflection, in inches (mm).

TABLE 2305.2(2)

VALUES OF Gt FOR USE IN CALCULATING DEFLECTION OF WOOD

STRUCTURAL PANEL SHEAR WALLS AND DIAPHRAGMS

PANEL TYPE SPAN RATING VALUES OF Gt (lb/in. panel depth or width)
OTHER STRUCTURAL I
3-ply Plywood 4-ply Plywood 5-plyPlywooda OSB 3-ply Plywood 4-ply Plywood 5-plyPlywooda OSB
Sheathing 24/0 25,000 32,500 37,500 77,500 32,500 42,500 41,500 77,500
24/16 27,000 35,000 40,500 83,500 35,000 45,500 44,500 83,500
32/16 27,000 35,000 40,500 83,500 35,000 45,500 44,500 83,500
40/20 28,500 37,000 43,000 88,500 37,000 48,000 47,500 88,500
48/24 31,000 40,500 46,500 96,000 40,500 52,500 51,000 96,000
Single Floor 16 o.c. 27,000 35,000 40,500 83,500 35,000 45,500 44,500 83,500
20 o.c. 28,000 36,500 42,000 87,000 36,500 47,500 46,000 87,000
24 o.c. 30,000 39,000 45,000 93,000 39,000 50,500 49,500 93,000
32 o.c. 36,000 47,000 54,000 110,000 47,000 61,000 59,500 110,000
48 o.c. 50,500 65,500 76,000 155,000 65,500 85,000 83,500 155,000

     OTHER STRUCTURAL I
Thickness (in.) A-A, A-C Marine All Other Grades A-A, A-C Marine All Other Grades
Sanded Plywood 1/4 24,000 31,000 24,000 31,000 31,000 31,000
11/32 25,500 33,000 25,500 33,000 33,000 33,000
3/8 26,000 34,000 26,000 34,000 34,000 34,000
15/32 38,000 49,500 38,000 49,500 49,500 49,500
1/2 38,500 50,000 38,500 50,000 50,000 50,000
19/32 49,000 63,500 49,000 63,500 63,500 63,500
5/8 49,500 64,500 49,500 64,500 64,500 64,500
  23/32 50,500 65,500 50,500 65,500 65,500 65,500
3/4 51,000 66,500 51,000 66,500 66,500 66,500
7/8 52,500 68,500 52,500 68,500 68,500 68,500
1 73,500 95,500 73,500 95,500 95,500 95,500
1 1/8 75,000 97,500 75,000 97,500 97,500 97,500

For SI: 1 inch = 25.4 mm, 1 pound/inch = 0.1751 N/mm.

a. Applies to plywood with five or more layers; for five-ply/three-layer plywood, use values for four ply.

SECTION 2306

ALLOWABLE STRESS DESIGN

2306.1 Allowable stress design. The structural analysis and construction of wood elements in structures using allowable stress design shall be in accordance with the following applicable standards:

American Forest & Paper Association.

NDS National Design Specification for Wood Construction

SDPWS Special Design Provisions for Wind and Seismic

American Institute of Timber Construction.

AITC 104 Typical Construction Details

AITC 110 Standard Appearance Grades for Structural Glued Laminated Timber

AITC 113 Standard for Dimensions of Structural Glued Laminated Timber

AITC 117 Standard Specifications for Structural Glued Laminated Timber of Softwood Species

AITC 119 Standard Specifications for Structural Glued Laminated Timber of Hardwood Species

ANSI/AITC A 190.1 Structural Glued Laminated Timber

AITC 200 Inspection Manual

American Society of Agricultural Engineers.

ASAE EP 484.2 Diaphragm Design of Metal-clad, Post-Frame Rectangular Buildings

ASAE EP 486.1 Shallow Post Foundation Design

ASAE 559 Design Requirements and Bending Properties for Mechanically Laminated Columns

APA-The Engineered Wood Association.

Panel Design Specification

Plywood Design Specification Supplement 1 - Design & Fabrication of Plywood Curved Panel

Plywood Design Specification Supplement 2 - Design & Fabrication of Glued

Plywood-lumber Beams Plywood Design Specification Supplement 3 - Design & Fabrication of Plywood Stressed-skin Panels

Plywood Design Specification Supplement 4 - Design & Fabrication of Plywood Sandwich Panels

Plywood Design Specification Supplement 5 - Design & Fabrication of All-plywood Beams

EWS T300 Glulam Connection Details

EWS S560 Field Notching and Drilling of Glued Laminated Timber Beams

EWS S475 Glued Laminated Beam Design Tables

EWS X450 Glulam in Residential Construction

EWS X440 Product and Application Guide: Glulam

EWS R540 Builders Tips: Proper Storage and Handling of Glulam Beams

Truss Plate Institute, Inc.

TPI 1 National Design Standard for Metal Plate Connected Wood Truss Construction

2306.1.1 Joists and rafters. The design of rafter spans is permitted to be in accordance with the AF&PA Span Tables for Joists and Rafters.

2306.1.2 Plank and beam flooring. The design of plank and beam flooring is permitted to be in accordance with the AF&PA Wood Construction Data No. 4.

2306.1.3 Treated wood stress adjustments. The allowable unit stresses for preservative-treated wood need no adjustment for treatment, but are subject to other adjustments.

The allowable unit stresses for fire-retardant-treated wood, including fastener values, shall be developed from an approved method of investigation that considers the effects of anticipated temperature and humidity to which the fire-retardant-treated wood will be subjected, the type of treatment and the redrying process. Other adjustments are applicable except that the impact load duration shall not apply.

2306.1.4 Lumber decking. The capacity of lumber decking arranged according to the patterns described in Section 2304.8.2 shall be the lesser of the capacities determined for flexure and deflection according to the formulas in Table 2306.1.4.

TABLE 2306.1.4

ALLOWABLE LOADS FOR LUMBER DECKING

Click to view

Click to view

2306.2 Wood diaphragms.

2306.2.1 Wood structural panel diaphragms. Wood structural panel diaphragms shall be designed and constructed in accordance with AF&PA SDPWS. Wood structural panel diaphragms are permitted to resist horizontal forces using the allowable shear capacities set forth in Table 2306.2.1(1) or 2306.2.1(2). The allowable shear capacities in Tables 2306.2.1(1) and 2306.2.1(2) are permitted to be increased 40 percent for wind design.

2306.2.2 Single diagonally sheathed lumber diaphragms. Single diagonally sheathed lumber diaphragms shall be designed and constructed in accordance with AF&PA SDPWS.

2306.2.3 Double diagonally sheathed lumber diaphragms. Double diagonally sheathed lumber diaphragms shall be designed and constructed in accordance with AF&PA SDPWS.

2306.2.4 Gypsum board diaphragm ceilings. Gypsum board diaphragm ceilings shall be in accordance with Section 2508.5.

2306.3 Wood structural panel shear walls. Wood structural panel shear walls shall be designed and constructed in accordance with AF&PA SDPWS. Wood structural panel shear walls are permitted to resist horizontal forces using the allowable capacities set forth in Table 2306.3. Allowable capacities in Table 2306.3 are permitted to be increased 40 percent for wind design.

2306.4 Lumber sheathed shear walls. Single and double diagonally sheathed lumber shear walls shall be designed and constructed in accordance with AF&PA SDPWS. Single and double diagonally sheathed lumber walls shall not be used to resist seismic forces in structures assigned to Seismic Design Category E or F.

2306.5 Particleboard shear walls. Particleboard shear walls shall be designed and constructed in accordance with AF&PA SDPWS. Particleboard shear walls shall be permitted to resist horizontal forces using the allowable shear capacities set forth in Table 2306.5. Allowable capacities in Table 2306.5 are permitted to be increased 40 percent for wind design. Particleboard shall not be used to resist seismic forces in structures assigned to Seismic Design Category D, E or F.

2306.6 Fiberboard shear walls. Fiberboard shear walls shall be designed and constructed in accordance with AF&PA SDPWS. Fiberboard shear walls are permitted to resist horizontal forces using the allowable shear capacities set forth in Table 2306.6. Allowable capacities in Table 2306.6 are permitted to be increased 40 percent for wind design. Fiberboard shall not be used to resist seismic forces in structures assigned to Seismic Design Category D, E or F.

2306.7 Shear walls sheathed with other materials. Shear walls sheathed with portland cement plaster, gypsum lath, gypsum sheathing or gypsum board shall be designed and constructed in accordance with AF&PA SDPWS. Shear walls sheathed with these materials are permitted to resist horizontal forces using the allowable shear capacities set forth in Table 2306.7. Shear walls sheathed with portland cement plaster, gypsum lath, gypsum sheathing or gypsum board shall not be used to resist seismic forces in structures assigned to Seismic Design Category E or F.

SECTION 2307

LOAD AND RESISTANCE FACTOR DESIGN

2307.1 Load and resistance factor design. The structural analysis and construction of wood elements and structures using load and resistance factor design shall be in accordance with AF&PA NDS and AF&PA SDPWS.

2307.1.1 Wood structural panel shear walls. In Seismic Design Category D, E or F, where shear design values exceed 490 pounds per foot (7154 N/m), all framing members receiving edge nailing from abutting panels shall not be less than a single 3-inch (76 mm) nominal member or two 2-inch (51 mm) nominal members fastened together in accordance with AF&PA NDS to transfer the design shear value between framing members. Wood structural panel joint and sill plate nailing shall be staggered at all panel edges. See Sections 4.3. 6.1 and 4.3. 6.4.3 of AF&PA SDPWS for sill plate size and anchorage requirements.

SECTION 2308

CONVENTIONAL LIGHT-FRAME CONSTRUCTION

2308.1 General. The requirements of this section are intended for conventional light-frame construction. Other methods are permitted to be used, provided a satisfactory design is submitted showing compliance with other provisions of this code. Interior nonload-bearing partitions, ceilings and curtain walls of conventional light-frame construction are not subject to the limitations of this section.

2308.1.1 Portions exceeding limitations of conventional construction.

When portions of a building of otherwise conventional construction exceed the limits of Section 2308.2, these portions and the supporting load path shall be designed in accordance with accepted engineering practice and the provisions of this code. For the purposes of this section, the term "portions" shall mean parts of buildings containing volume and area such as a room or a series of rooms.

TABLE 2306.2.1(1)

ALLOWABLE SHEAR (POUNDS PER FOOT) FOR WOOD

STRUCTURAL PANEL DIAPHRAGMS WITH FRAMING OF DOUGLAS

FIR-LARCH, OR SOUTHERN PINEa FOR WIND OR SEISMIC

LOADINGh

PANEL GRADE COMMON NAIL SIZE ORSTAPLEf LENGTH ANDGAGE MINIMUM FASTENERPENETRATION INFRAMING (inches) MINIMUM NOMINALPANELTHICKNESS (inch) MINIMUM NOMINALWIDTH OF FRAMINGMEMBERS AT ADJOININGPANEL EDGES ANDBOUNDARIESg (inches) BLOCKED DIAPHRAGMS UNBLOCKED DIAPHRAGMS
Fastener spacing (inches) at diaphragmboundaries (all cases)at continuous paneledges parallel to load(Cases 3, 4), and at allpanel edges (Cases 5, 6)b Fasteners spaced 6" max. at supported edgesb
6 4 2 ½c 2c Case 1 (No unblocked edgesor continuousjoints parallel toload) All other configurations (Cases 2, 3, 4,5 and 6)
Fastener spacing (inches) at other panel edges(Cases 1, 2, 3 and 4)b
6 6 4 3
Structural I grades 8d (2 ½" x 0.131 ") 13/8 3 / 8 2 270 360 530 600 240 180
3 300 400 600 675 265 200
1 ½16 Gage 1 2 175 235 350 400 155 115
3 200 265 395 450 175 130
10dd (3" x 0.148 ") 1 ½ 15 / 32 2 320 425 640 730 285 215
          3 360 480 720 820 320 240
1 ½16 Gage 1 2 175 235 350 400 155 120
3 200 265 395 450 175 130
Sheathing, single floor and other grades covered in DOC PS 1 and PS 2 6de (2" x 0.113 ") 1 1/4 3 / 8 2 185 250 375 420 165 125
3 210 280 420 475 185 140
8d (2 ½" x 0.131 ") 1 3/8 2 240 320 480 545 215 160
3 270 360 540 610 240 180
1 ½ 16 Gage 1 2 160 210 315 360 140 105
3 180 235 355 400 160 120
8d (2 ½" x 0.131 ") 1 3/8 7/ 16 2 255 340 505 575 230 170
3 285 380 570 645 255 190
1 1/ 2 16 Gage 1 2 165 225 335 380 150 110
3 190 250 375 425 165 125
8d (2 ½" x 0.131 ") 1 3/8 15 / 32 2 270 360 530 600 240 180
3 300 400 600 675 265 200
10dd (3" x 0.148 ") 1 ½ 2 290 385 575 655 255 190
3 325 430 650 735 290 215
1 ½ 16 Gage 1 2 160 210 315 360 140 105
3 180 235 355 405 160 120
10dd (3" x 0.148 ") 1 ½ 19/32 2 320 425 640 730 285 215
3 360 480 720 820 320 240
1 3/4 16 Gage 1 2 175 235 350 400 155 115
3 200 265 395 450 175 130

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-3.jpg

For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.

a. For framing of other species: (1) Find specific gravity for species of lumber in AF&PA NDS. (2) For staples find shear value from table above for Structural I panels (regardless of actual grade) and multiply value by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species. (3) For nails find shear value from table above for nail size for actual grade and multiply value by the following adjustment factor: Specific Gravity Adjustment Factor = [1-( 0.5 SG)], where SG = Specific Gravity of the framing lumber. This adjustment factor shall not be greater than 1.

b. Space fasteners maximum 12 inches o.c. along intermediate framing members (6 inches o.c. where supports are spaced 48 inches o.c.).

c. Framing at adjoining panel edges shall be 3 inches nominal or wider, and nails at all panel edges shall be staggered where panel edge nailing is specified at 2 ½ inches o.c. or less.

d. Framing at adjoining panel edges shall be 3 inches nominal or wider, and nails at all panel edges shall be staggered where both of the following conditions are met:

(1) 10d nails having penetration into framing of more than 1 ½ inches and

(2) panel edge nailing is specified at 3 inches o.c. or less.

e. 8d is recommended minimum for roofs due to negative pressures of high winds.

f. Staples shall have a minimum crown width of 7 /16 inch and shall be installed with their crowns parallel to the long dimension of the framing members.

g. The minimum nominal width of framing members not located at boundaries or adjoining panel edges shall be 2 inches.

h. For shear loads of normal or permanent load duration as defined by the AF&PA NDS, the values in the table above shall be multiplied by 0.63 or 0.56, respectively.

TABLE 2306.2.1(2)

ALLOWABLE SHEAR (POUNDS PER FOOT) FOR WOOD

STRUCTURAL PANEL BLOCKED DIAPHRAGMS UTILIZING

MULTIPLE ROWS OF FASTENERS (HIGH LOAD DIAPHRAGMS)

WITH FRAMING OF DOUGLAS FIR-LARCH OR SOUTHERN PINEa

FOR WIND OR SEISMIC LOADINGb, g, h

PANEL GRADEc COMMON NAIL SIZE OR STAPLEf GAGE MINIMUM FASTENER PENETRATION IN FRAMING (inches) MINIMUM NOMINAL PANEL THICKNESS (inch) MINIMUM NOMINAL WIDTH OF FRAMING MEMBER AT ADJOINING PANEL EDGES AND BOUNDARIESe LINES OF FASTENERS BLOCKED DIAPHRAGMS
Cases 1 and 2d
Fastener Spacing Per Line at Boundaries (inches)
4 2 ½ 2
Fastener Spacing Per Line at Other Panel Edges (inches)
6 4 4 3 3 2
Structural I grades 10dcommonnails 1 ½ 15/32 3 2 605 815 875 1,150 - -
4 2 700 915 1,005 1,290 - -
4 3 875 1,220 1,285 1,395 - -
19/32 3 2 670 880 965 1,255 - -
4 2 780 990 1,110 1,440 - -
4 3 965 1,320 1,405 1,790 - -
23/32 3 2 730 955 1,050 1,365 - -
4 2 855 1,070 1,210 1,565 - -
4 3 1,050 1,430 1,525 1,800 - -
Sheathingsinglefloor andothergradescovered inDOC PS 1and PS 2 14 gage staples 2 15/32 3 2 600 600 860 960 1,060 1,200
4 3 860 900 1,160 1,295 1,295 1,400
19/32 3 2 600 600 875 960 1,075 1,200
4 3 875 900 1,175 1,440 1,475 1,795
10dcommonnails 1 ½ 15/32 3 2 525 725 765 1,010 - -
4 2 605 815 875 1,105 - -
4 3 765 1,085 1,130 1,195 - -
19/32 3 2 650 860 935 1,225 - -
4 2 755 965 1,080 1,370 - -
4 3 935 1,290 1,365 1,485 - -
23/32 3 2 710 935 1,020 1,335 - -
4 2 825 1,050 1,175 1,445 - -
4 3 1,020 1,400 1,480 1,565 - -
14 gage staples 2 15/32 3 2 540 540 735 865 915 1,080
4 3 735 810 1,005 1,105 1,105 1,195
19/32 3 2 600 600 865 960 1,065 1,200
4 3 865 900 1,130 1,430 1,370 1,485
23/32 4 3 865 900 1,130 1,490 1,430 1,545

For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.

a. For framing of other species: (1) Find specific gravity for species of framing lumber in AF&PA NDS. (2) For staples, find shear value from table above for Structural I panels (regardless of actual grade) and multiply value by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species. (3) For nails, find shear value from table above for nail size of actual grade and multiply value by the following adjustment factor: Specific Gravity Adjustment Factor = [ 1-( 0.5 - SG)], where SG = Specific gravity of the framing lumber. This adjustment factor shall not be greater than 1.

b. Fastening along intermediate framing members: Space fasteners a maximum of 12 inches on center, except 6 inches on center for spans greater than 32 inches.

c. Panels conforming to PS 1 or PS 2.

d. This table gives shear values for Cases 1 and 2 as shown in Table 2306.2.1(1). The values shown are applicable to Cases 3, 4, 5 and 6 as shown in Table 2306.2.1(1), providing fasteners at all continuous panel edges are spaced in accordance with the boundary fastener spacing.

e. The minimum nominal depth of framing members shall be 3 inches nominal. The minimum nominal width of framing members not located at boundaries or adjoining panel edges shall be 2 inches.

f. Staples shall have a minimum crown width of 7/16 inch, and shall be installed with their crowns parallel to the long dimension of the framing members.

g. High load diaphragms shall be subject to special inspection in accordance with Section 1704.6.1.

h. For shear loads of normal or permanent load duration as defined by the AF&PA NDS, the values in the table above shall be multiplied by 0.63 or 0.56, respectively.

TABLE 2306.2.1(2)-continued

ALLOWABLE SHEAR (POUNDS PER FOOT) FOR WOOD

STRUCTURAL PANEL BLOCKED DIAPHRAGMS UTILIZING

MULTIPLE ROWS OF FASTENERS (HIGH LOAD DIAPHRAGMS)

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-4.png

WITH FRAMING OF DOUGLAS FIR-LARCH OR SOUTHERN PINE FOR WIND OR SEISMIC LOADING

TABLE 2306.3

ALLOWABLE SHEAR (POUNDS PER FOOT) FOR WOOD

STRUCTURAL PANEL SHEAR WALLS WITHFRAMING OF DOUGLAS

FIR-LARCH OR SOUTHERN PINEa FORWINDORSEISMIC LOADINGb,

h, i, j, l

PANEL GRADE MINIMUM NOMINAL PANELTHICKNESS (inch) MINIMUM FASTENER PENETRATION INFRAMING (inches) PANELS APPLIED DIRECT TO FRAMING PANELS APPLIED OVER ½" OR 5/8" GYPSUM SHEATHING
NAIL (common or galvanized box) or staplesizek Fastener spacing at panel edges (inches) NAIL (common or galvanized box) or staple sizek Fastener spacing at panel edges (inches)
6 4 3 2e 6 4 3 2e
Structural I sheathing 3/8 1 3/8 8d (2 ½" x 0.131" common,2 ½" x 0.113 " galvanizedbox) 230d 360d 460d 610d 10d (3" x 0.148 " common, 3" x 0.128 " galvanized box) 280 430 550f 730
1 1 ½ 16 Gage 155 235 315 400 2 16 Gage 155 235 310 400
7/16 13/8 8d (2 1/2" x 0.131 "common,2 ½" x 0.113 " galvanizedbox) 255d 395d 505d 670d 10d (3" x 0.148 " common, 3" x 0.128 " galvanized box) 280 430 550f 730
1 1 ½ 16 Gage 170 260 345 440 2 16 Gage 155 235 310 400
15/32 13/8 8d (2 ½" x 0.131 " common,2 ½" x 0.113 " galvanizedbox) 280 430 550 730 10d (3" x 0.148 " common, 3" x 0.1218 " galvanized box) 280 430 550f 730
1 1 ½ 16 Gage 185 280 375 475 2 16 Gage 155 235 300 400
1 ½ 10d (3" x 0.148 " common, 3" x 0.128 " galvanized box) 340 510 665f 870 10d (3" x 0.148 " common, 3" x 0.128 " galvanized box) - - - -
Sheathing, plywoodsidinggexcept Group 5 Species 5/16cor 1/4 c 1 1/4 6d (2" x 0.113 " common, 2" x 0.099 " galvanized box) 180 270 350 450 8d (2 ½" x 0.131 " common, 2 ½" x 0.113 " galvanized box) 180 270 350 450
1 1 ½ 16 Gage 145 220 295 375 2 16 Gage 110 165 220 285
5/16 c 1 1/4 6d (2" x 0.099 ") 140 210 275 360 8d (2 ½" x 0.113 ") 140 210 275 360
3/8c 13/8 8d (2 ½" x 0.113 ") 160 240 310 410 10d (3" x 0.128 ") 160 240 310f 410

For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.

a. For framing of other species: (1) Find specific gravity for species of lumber in AF&PA NDS. (2) For staples find shear value from table above for Structural I panels (regardless of actual grade) and multiply value by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species. (3) For nails find shear value from table above for nail size for actual grade and multiply value by the following adjustment factor: Specific Gravity Adjustment Factor = [1-( 0.5 -SG)], where SG = Specific Gravity of the framing lumber. This adjustment factor shall not be greater than1.

b. Panel edges backed with 2-inch nominal or wider framing. Install panels either horizontally or vertically. Space fasteners maximum 6 inches on center along intermediate framing membersfor 3/8-inch and 7/16-inch panels installed on studs spaced 24 inches on center. For other conditions and panel thickness, space fasteners maximum 12 inches on center on intermediate supports.

c. 3/8-inch panel thickness or siding with a span rating of 16 inches on center is the minimum recommended where applied directly to framing as exterior siding. For grooved panel siding, the nominal panel thickness is the thickness of the panel measured at the point of nailing.

d. Allowable shear values are permitted to be increased to values shown for 15/32-inch sheathing with same nailing provided (a) studs are spaced a maximum of 16 inches on center, or (b) panels are applied with long dimension across studs.

e. Framing at adjoining panel edges shall be 3 inches nominal or wider, and nails at all panel edges shall be staggered where panel edge nailing is specified at 2 inches on center or less.

f. Framing at adjoining panel edges shall be 3 inches nominal or wider, and nails at all panel edges shall be staggered where both of the following conditions are met: (1) 10d (3" x 0.148 ") nails having penetration into framing of more than 1 ½ inches and (2) panel edge nailing is specified at 3 inches on center or less.

g. Values apply to all-veneer plywood. Thickness at point of fastening on panel edges governs shear values.

h. Where panels are applied on both faces of a wall and nail spacing is less than 6 inches o.c. on either side, panel joints shall be offset to fall on different framing members. Or framing shall be 3-inch nominal or thicker at adjoining panel edges and nails at all panel edges shall be staggered.

i. In Seismic Design Category D, E or F, where shear design values exceed 350 pounds per linear foot, all framing members receiving edge nailing from abutting panels shall not be less than a single 3-inch nominal member, or two 2-inch nominal members fastened together in accordance with Section 2306.1 to transfer the design shear value between framing members. Wood structural panel joint and sill plate nailing shall be staggered at all panel edges. See Sections 4.3. 6.1 and 4.3. 6.4.3 of AF&PA SDPWS for sill plate size and anchorage requirements.

j. Galvanized nails shall be hot dipped or tumbled.

k. Staples shall have a minimum crown width of 7/16 inch and shall be installed with their crowns parallel to the long dimension of the framing members.

l. For shear loads of normal or permanent load duration as defined by the AF&PA NDS, the values in the table above shall be multiplied by 0.63 or 0.56, respectively.

TABLE 2306.5

ALLOWABLE SHEAR FOR PARTICLEBOARD SHEAR WALL

SHEATHINGb

PANEL GRADE MINIMUM NOMINALPANELTHICKNESS(inch) MINIMUMNAILPENETRATIONIN FRAMING(inches) PANELS APPLIED DIRECT TO FRAMING
Nail size (common or galvanized box) Allowable shear (pounds per foot) nail spacing at panel edges (inches)a
6 4 3 2
M-S "Exterior Glue" and M-2 "Exterior Glue" 3/8 1 ½ 6d 120 180 230 300
3/8 1 ½ 8d 130 190 240 315
½ 140 210 270 350
  ½ 1 5/8 10d 185 275 360 460
5/8 200 305 395 520

For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.

a. Values are not permitted in Seismic Design Category D, E or F.

b. Galvanized nails shall be hot-dipped or tumbled.

TABLE 2306.6

ALLOWABLE SHEAR VALUES (plf) FOR WIND OR SEISMIC

LOADING ON

SHEAR WALLS OF FIBERBOARD SHEATHING BOARD

CONSTRUCTION FOR TYPE V CONSTRUCTION ONLYa, b, c, d, e

THICKNESS AND GRADE FASTENER SIZE ALLOWABLE SHEAR VALUE(pounds per linear foot)NAIL SPACING AT PANEL EDGES (inches)a
4 3 2
½" or 25/32" Structural No. 11 gage galvanized roofing nail 1 ½" long for 25/32" with 3/8" head 170 230 260
No. 11 gage galvanized staple, 7/16" crownf 150 200 225
No. 11 gage galvanized staple, 1" crownf 220 290 325

For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.

a. Fiberboard sheathing shall not be used to brace concrete or masonry walls.

b. Panel edges shall be backed with 2-inch or wider framing of Douglas fir-larch or Southern pine. For framing of other species: (1) Find specific gravity for species of framing lumber in AF&PA NDS. (2) For staples, multiply the shear value from the table above by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species. (3) For nails, multiply the shear value from the table above by the following adjustment factor: specific gravity adjustment factor = [1-( 0.5 -SG)], where SG = Specific gravity of the framing lumber.

c. Values shown are for fiberboard sheathing on one side only with long panel dimension either parallel or perpendicular to studs.

d. Fastener shall be spaced 6 inches on center along intermediate framing members.

e. Values are not permitted in Seismic Design Category D, E or F.

f. Staple length shall not be less than 1 ½ inches for 25/32-inch sheathing or 1 1/4 inches for ½ -inch sheathing.

TABLE 2306.7

ALLOWABLE SHEAR FOR WIND OR SEISMIC FORCES FOR SHEAR

WALLS OF LATH AND PLASTER OR GYPSUM BOARD WOOD

FRAMED WALL ASSEMBLIES

TYPE OF MATERIAL THICKNESSOF MATERIAL WALL CONSTRUCTION FASTENERSPACINGbMAXIMUM (inches) SHEARVALUEa,e(plf) MINIMUM FASTENER SIZEc,d,j,k
1. Expanded metal orwoven wire lath andportland cement plaster 7/8" Unblocked 6 180 No. 11 gage 1½"long, 7/16" head No. 16 gage galv. staple,7/8" legs
2. Gypsum lath, plain orperforated with verticaljoints staggered 3/8" lath and ½" plaster Unblocked 5 180 No. 13 gage galv. 11/8" long,19/64" head, plasterboard nail
3. Gypsum lath, plain or perforated 3/8" lath and ½" plaster Unblocked 5 100 No. 16 gage galv. staple, 11/8" long, 0.120 " nail, min. 3/8" head, 11/4" long
4. Gypsum board, gypsumveneerbase or water-resistantgypsum backing board 1/2" Unblockedf 7 75 5d cooler (15/8" x 0.086 ") orwallboard 0.120 " nail, min.3/8" head,11/2" long No. 16 gage galv. staple,11/2" long.
UnblockedfUnblocked 4 110
Unblocked 7 100
Unblocked 4 125
Blockedg 7 125
Blockedg 4 150
Unblocked 8/12h 60 No. 6-11/4" screwsi
Blockedg 4/16h 160
Blockedf,g 4/12h 155
Blockedg 8/12h 70
Blockedg 6/12h 90
5/8" Unblockedf 7 115 6d cooler (17/8" x 0.092 ") orwallboard 0.120 "nail, min.3/8" head,13/4"long No. 16 gage galv. staple,11/2"legs, 15/8"long
4 145
Blockedg 7 145
4 175
BlockedgTwo-ply Base ply: 9 Face ply: 7 250 Base ply-6d cooler (17/8" x 0.092 ") orwallboard 13/4" x 0.120 " nail, min.3/8" head 15/8" 16 gage galv. staple 15/8" 16 gage galv. staple Face ply-8dcooler (23/8" x 0.113 ") or wallboard 0.120 " nail, min.3/8"head, 23/8"longNo. 15 gage galv. staple, 21/4"long
Unblocked 8/12h 70 No. 6"1 1/4" screwsi
Blockedg 8/12h 90

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per foot = 14.5939 N/m.

a. These shear walls shall not be used to resist loads imposed by masonry or concrete walls (see Section 4.1.5 of AF & PA SDPWS). Values shown are for short-term loading due to wind or seismic loading. Walls resisting seismic loads shall be subject to the limitations in Section 12.2.1 of ASCE 7. Values shown shall be reduced 25 percent for normal loading.

b. Applies to fastening at studs, top and bottom plates and blocking.

c. Alternate fasteners are permitted to be used if their dimensions are not less than the specified dimensions. Drywall screws are permitted to substitute for the 5d (15/8" x 0.086 "), and 6d (17/8" x 0.092 ")(cooler) nails listed above, and No. 6 11/4 inch Type S or W screws for 6d (17/8" x 0.092 ) (cooler) nails.

d. For properties of cooler nails, see ASTM C 514.

e. Except as noted, shear values are based on a maximum framing spacing of 16 inches on center.

f. Maximum framing spacing of 24 inches on center.

g. All edges are blocked, and edge fastening is provided at all supports and all panel edges.

h. First number denotes fastener spacing at the edges; second number denotes fastener spacing at intermediate framing members.

i. Screws are Type W or S.

j. Staples shall have a minimum crown width of 7 /16 inch, measured outside the legs, and shall be installed with their crowns parallel to the long dimension of the framing members.

k. Staples for the attachment of gypsum lath and woven-wire lath shall have a minimum crownwidth of 3 /4 inch, measured outside the legs.

2308.2 Limitations. Buildings are permitted to be constructed in accordance with the provisions of conventional light-frame construction, subject to the following limitations, and to further limitations of Sections 2308.11 and 2308.12.

1. Buildings shall be limited to a maximum of three stories above grade plane. For the purposes of this section, for buildings in Seismic Design Category D or E as determined in Section 1613, cripple stud walls shall be considered to be a story.

Exception: Solid blocked cripple walls not exceeding 14 inches (356 mm) in height need not be considered a story.

2. Maximum floor-to-floor height shall not exceed 11 feet, 7 inches (3531 mm). Bearing wall height shall not exceed a stud height of 10 feet (3048 mm).

3. Loads as determined in Chapter 16 shall not exceed the following:

1.1Average dead loads shall not exceed 15 psf (718 N/m2) for combined roof and ceiling, exterior walls, floors and partitions.

Exceptions:

1. Subject to the limitations of Sections 2308.11.2 and 2308.12.2, stone or masonry veneer up to the lesser of 5 inches (127 mm) thick or 50 psf (2395 N/m 2) and installed in accordance with Chapter 14 is permitted to a height of 30 feet (9144 mm) above a noncombustible foundation, with an additional 8 feet (2438 mm) permitted for gable ends.

2. Concrete or masonry fireplaces, heaters and chimneys shall be permitted in accordance with the provisions of this code.

1.2Live loads shall not exceed 40 psf (1916 N/m2) for floors.

1.3Ground snow loads shall not exceed 50 psf (2395 N/m2).

4. Wind speeds shall not exceed 100 miles per hour (mph) (44 m/s) (3-second gust).

Exception: Wind speeds shall not exceed 110 mph ( 48.4 m/s) (3-second gust) for buildings in Exposure Category B that are not located in a hurricane-prone region.

5. Roof trusses and rafters shall not span more than 40 feet (12 192 mm) between points of vertical support.

6. The use of the provisions for conventional light-frame construction in this section shall not be permitted for Occupancy Category IV buildings assigned to Seismic Design Category B, C, D, E or F, as determined in Section 1613.

7. Conventional light-frame construction is limited in irregular structures in Seismic Design Category DorE, as specified in Section 2308.12.6.

2308.2.1 Basic wind speed greater than 100 mph (3-second gust). Where the basic wind speed exceeds 100 mph (3-second gust), the provisions of either AF&PA WFCM or ICC 600 are permitted to be used.

2308.2.2 Buildings in Seismic Design Category B, C, D or

E. Buildings of conventional light-frame construction in Seismic Design Category B or C, as determined in Section 1613, shall comply with the additional requirements in Section 2308.11.

Buildings of conventional light-frame construction in Seismic Design Category D or E, as determined in Section 1613, shall comply with the additional requirements in Section 2308.12.

2308.3 Braced wall lines. Buildings shall be provided with exterior and interior braced wall lines as described in Section 2308.9.3 and installed in accordance with Sections 2308.3.1 through 2308.3.4.

2308.3.1 Spacing. Spacing of braced wall lines shall not exceed 35 feet (10 668 mm) o.c. in both the longitudinal and transverse directions in each story.

2308.3.2 Braced wall line connections. Wind and seismic lateral forces shall be transferred from the roofs and floors to braced wall lines and from the braced wall lines in upper stories to the braced wall lines in the story below in accordance with this section.

Braced wall line top plates shall be fastened to joists, rafters or full-depth blocking above in accordance with Table 2304.9.1, Items 11, 12, 15 or 19 as applicable based on the orientation of the joists or rafters to the braced wall line. Braced wall line bottom plates shall be connected to joists or blocking below in accordance with Table 2304.9.1, Item 6, or to foundations in accordance with Section 2308.3.3. At exterior gable end walls, braced wall panel sheathing in the top story shall be extended and fastened to roof framing where the spacing between parallel exterior braced wall lines is greater than 50 feet (15 240 mm).

Exception: Where roof trusses are used and are installed perpendicular to an exterior braced wall line, lateral forces shall be transferred from the roof diaphragm to the braced wall by blocking of the ends of the trusses or by other approved methods providing equivalent lateral force transfer. Blocking shall be a minimum of 2 inches (51 mm) nominal in thickness and equal to the depth of the truss at the wall line and shall be fastened to the braced wall line top plate as specified in Table 2304.9.1, Item 11.

2308.3.3 Sill anchorage. Where foundations are required by Section 2308.3.4, braced wall line sills shall be anchored to concrete or masonry foundations. Such anchorage shall conform to the requirements of Section 2308.6 except that such anchors shall be spaced at not more than 4 feet (1219 mm) o.c. for structures over two stories above grade plane. The anchors shall be distributed along the length of the braced wall line. Other anchorage devices having equivalent capacity are permitted.

2308.3. 3.1 Anchorage to all-wood foundations. Where all-wood foundations are used, the force transfer from the braced wall lines shall be determined based on calculation and shall have a capacity greater than or equal to the connections required by Section 2308.3.3.

2308.3.4 Braced wall line support. Braced wall lines shall be supported by continuous foundations.

Exception: For structures with a maximum plan dimension not over 50 feet (15 240 mm), continuous foundations are required at exterior walls only.

2308.4 Design of elements. Combining of engineered elements or systems and conventionally specified elements or systems is permitted subject to the following limits:

2308.4.1 Elements exceeding limitations of conventional construction.

When a building of otherwise conventional construction contains structural elements exceeding the limits of Section 2308.2, these elements and the supporting load path shall be designed in accordance with accepted engineering practice and the provisions of this code.

2308.4.2 Structural elements or systems not described herein. When a building of otherwise conventional construction contains structural elements or systems not described in Section 2308, these elements or systems shall be designed in accordance with accepted engineering practice and the provisions of this code. The extent of such design need only demonstrate compliance of the nonconventional elements with other applicable provisions of this code and shall be compatible with the performance of the conventionally framed system.

2308.5 Connections and fasteners. Connections and fasteners used in conventional construction shall comply with the requirements of Section 2304.9.

2308.6 Foundation plates or sills. Foundations and footings shall be as specified in Chapter 18. Foundation plates or sills resting on concrete or masonry foundations shall comply with Section 2304.3.1. Foundation plates or sills shall be bolted or anchored to the foundation with not less than ½-inch-diameter ( 12.7 mm) steel bolts or approved anchors spaced to provide equivalent anchorage as the steel bolts. Bolts shall be embedded at least 7 inches (178 mm) into concrete or masonry, and spaced not more than 6 feet (1829 mm) apart. There shall be a minimum of two bolts or anchor straps per piece with one bolt or anchor strap located not more than 12 inches (305 mm) or less than 4 inches (102 mm) from each end of each piece. A properly sized nut and washer shall be tightened on each bolt to the plate.

2308.7 Girders. Girders for single-story construction or girders supporting loads from a single floor shall not be less than 4 inches by 6 inches (102 mm by 152 mm) for spans 6 feet (1829 mm) or less, provided that girders are spaced not more than 8 feet (2438 mm) o.c. Spans for built-up 2-inch (51 mm) girders shall be in accordance with Table 2308.9.5 or 2308.9.6. Other girders shall be designed to support the loads specified in this code. Girder end joints shall occur over supports.

Where a girder is spliced over a support, an adequate tie shall be provided. The ends of beams or girders supported on masonry or concrete shall not have less than 3 inches (76 mm) of bearing.

2308.8 Floor joists. Spans for floor joists shall be in accordance with Table 2308.8(1) or 2308.8(2). For other grades and or species, refer to the AF&PA Span Tables for Joists and Rafters.

2308.8.1 Bearing. Except where supported on a 1-inch by 4-inch ( 25.4 mm by 102 mm) ribbon strip and nailed to the adjoining stud, the ends of each joistshall not have less than 1 1 /2 inches (38 mm) of bearing on wood or metal, or less than 3 inches (76 mm) on masonry.

2308.8.2 Framing details. Joists shall be supported laterally at the ends and at each support by solid blocking except where the ends of the joists are nailed to a header, band or rim joist or to an adjoining stud or by other means. Solid blocking shall not be less than 2 inches (51mm) in thickness and the full depth of the joist. Notches on the ends of joists shall not exceed one-fourth the joist depth. Holes bored in joists shall not be within 2 inches (51 mm) of the top or bottom of the joist, and the diameter of any such hole shall not exceed one-third the depth of the joist. Notches in the top or bottom of joists shall not exceed one-sixth the depth and shall not be located in the middle third of the span.

Joist framing from opposite sides of a beam, girder or partition shall be lapped at least 3 inches (76 mm) or the opposing joists shall be tied together in an approved manner.

Joists framing into the side of a wood girder shall be supported by framing anchors or on ledger strips not less than 2 inches by 2 inches (51 mm by 51 mm).

2308.8. 2.1 Engineered wood products. Cuts, notches and holes bored in trusses, structural composite lumber, structural glue-laminated members or I-joists are not permitted except where permitted by the manufacturer's recommendations or where the effects of such alterations are specifically considered in the design of the member by a registered design professional.

2308.8.3 Framing around openings. Trimmer and header joists shall be doubled, or of lumber of equivalent cross section, where the span of the header exceeds 4 feet (1219 mm). The ends of header joists more than 6 feet (1829 mm) long shall be supported by framing anchors or joist hangers unless bearing on a beam, partition or wall. Tail joists over 12 feet (3658 mm) long shall be supported at the header by framing anchors or on ledger strips not less than 2 inches by 2 inches (51 mm by 51 mm).

2308.8.4 Supporting bearing partitions. Bearing partitions parallel to joists shall be supported on beams, girders, doubled joists, walls or other bearing partitions. Bearing partitions perpendicular to joists shall not be offset from supporting girders, walls or partitions more than the joist depth unless such joists are of sufficient size to carry the additional load.

TABLE 2308.8(1) FLOOR JOIST SPANS FOR COMMON LUMBER SPECIES

(Residential Sleeping Areas, Live Load = 30 psf, L/[DELTA] = 360)

JOISTSPACING(inches) SPECIES AND GRADE DEAD LOAD = 10 psf DEAD LOAD = 20 psf
2x6 2x8 2x10 2x12 2x6 2x8 2x10 2x12
Maximum floor joist spans
(ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.)
12 Douglas Fir-Larch SS 12-6 16-6 21-0 25-7 12-6 16-6 21-0 25-7
Douglas Fir-Larch #1 12-0 15-10 20-3 24-8 12-0 15-7 19-0 22-0
Douglas Fir-Larch #2 11-10 15-7 19-10 23-0 11-6 14-7 17-9 20-7
Douglas Fir-Larch #3 9-8 12-4 15-0 17-5 8-8 11-0 13-5 15-7
Hem-Fir SS 11-10 15-7 19-10 24-2 11-10 15-7 19-10 24-2
Hem-Fir #1 11-7 15-3 19-5 23-7 11-7 15-2 18-6 21-6
Hem-Fir #2 11-0 14-6 18-6 22-6 11-0 14-4 17-6 20-4
Hem-Fir #3 9-8 12-4 15-0 17-5 8-8 11-0 13-5 15-7
Southern Pine SS 12-3 16-2 20-8 25-1 12-3 16-2 20-8 25-1
Southern Pine #1 12-0 15-10 20-3 24-8 12-0 15-10 20-3 24-8
Southern Pine #2 11-10 15-7 19-10 24-2 11-10 15-7 18-7 21-9
Southern Pine #3 10-5 13-3 15-8 18-8 9-4 11-11 14-0 16-8
Spruce-Pine-Fir SS 11-7 15-3 19-5 23-7 11-7 15-3 19-5 23-7
Spruce-Pine-Fir #1 11-3 14-11 19-0 23-0 11-3 14-7 17-9 20-7
Spruce-Pine-Fir #2 11-3 14-11 19-0 23-0 11-3 14-7 17-9 20-7
Spruce-Pine-Fir #3 9-8 12-4 15-0 17-5 8-8 11-0 13-5 15-7
16 Douglas Fir-Larch SS 11-4 15-0 19-1 23-3 11-4 15-0 19-1 23-0
Douglas Fir-Larch #1 10-11 14-5 18-5 21-4 10-8 13-6 16-5 19-1
Douglas Fir-Larch #2 10-9 14-1 17-2 19-11 9-1 12-7 15-5 17-10
Douglas Fir-Larch #3 8-5 10-8 13-0 15-1 17-6 9-6 11-8 13-6
Hem-Fir SS 10-9 14-2 18-0 21-11 10-9 14-2 18-0 21-11
Hem-Fir #1 10-6 13-10 17-8 20-9 10-4 13-1 16-0 18-7
Hem-Fir #2 10-0 13-2 16-10 19-8 9-10 12-5 15-2 17-7
Hem-Fir #3 8-5 10-8 13-0 15-1 7-6 9-6 11-8 13-6
  Southern Pine SS 11-2 14-8 18-9 22-10 11-2 14-8 18-9 22-10
Southern Pine #1 10-11 14-5 18-5 22-5 10-11 14-5 17-11 21-4
Southern Pine #2 10-9 14-2 18-0 21-1 10-5 13-6 16-1 18-10
Southern Pine #3 9-0 11-6 13-7 16-2 8-1 10-3 12-2 14-6
Spruce-Pine-Fir SS 10-6 13-10 17-8 21-6 10-6 13-10 17-8 21-4
Spruce-Pine-Fir #1 10-3 13-6 17-2 19-11 9-1 12-7 15-5 17-10
Spruce-Pine-Fir #2 10-3 13-6 17-2 19-11 19-1 12-7 15-5 17-10
Spruce-Pine-Fir #3 8-5 10-8 13-0 15-1 17-6 9-6 11-8 13-6
19.2 Douglas Fir-Larch SS 10-8 14-1 18-0 21-10 10-8 14-1 18-0 21-0
Douglas Fir-Larch #1 10-4 13-7 16-9 19-6 9-8 12-4 15-0 17-5
Douglas Fir-Larch #2 10-1 12-10 15-8 18-3 9-1 11-6 14-1 16-3
Douglas Fir-Larch #3 7-8 9-9 11-10 13-9 6-10 8-8 10-7 12-4
Hem-Fir SS 10-1 13-4 17-0 20-8 10-1 13-4 17-0 20-7
Hem-Fir #1 9-10 13-0 16-4 19-0 9-6 12-0 14-8 17-0
Hem-Fir #2 9-5 12-5 15-6 17-1 8-11 11-4 13-10 16-1
Hem-Fir #3 7-8 9-9 11-10 13-9 6-10 8-8 10-7 12-4
Southern Pine SS 10-6 13-10 17-8 21-6 10-6 13-10 17-8 21-6
Southern Pine #1 10-4 13-7 17-4 21-1 10-4 13-7 16-4 19-6
Southern Pine #2 10-1 13-4 16-5 19-3 9-6 12-4 14-8 17-2
Southern Pine #3 8-3 10-6 12-5 14-9 7-4 9-5 11-1 13-2
Spruce-Pine-Fir SS 9-10 13-0 16-7 20-2 9-10 13-0 16-7 19-6
Spruce-Pine-Fir #1 9-8 12-9 15-8 18-3 9-1 11-6 14-1 16-3
Spruce-Pine-Fir #2 9-8 12-9 15-8 18-3 9-1 11-6 14-1 16-3
Spruce-Pine-Fir #3 7-8 9-9 11-10 13-9 6-10 8-8 10-7 12-4
24 Douglas Fir-Larch SS 9-11 13-1 16-8 20-3 9-11 13-1 16-2 18-9
Douglas Fir-Larch #1 9-7 12-4 15-0 17-5 8-8 11-0 13-5 15-7
Douglas Fir-Larch #2 9-1 11-6 14-1 16-3 8-1 10-3 12-7 14-7
Douglas Fir-Larch #3 6-10 8-8 10-7 12-4 6-2 7-9 9-6 11-0
Hem-Fir SS 9-4 12-4 15-9 19-2 9-4 12-4 15-9 18-5
Hem-Fir #1 9-2 12-0 14-8 17-0 8-6 10-9 13-1 15-2
Hem-Fir #2 8-9 11-4 13-10 16-1 8-0 10-2 12-5 14-4
Hem-Fir #3 6-10 8-8 10-7 12-4 6-2 7-9 9-6 11-0
Southern Pine SS 9-9 12-10 16-5 19-11 9-9 12-10 16-5 19-11
Southern Pine #1 9-7 12-7 16-1 19-6 9-7 12-4 14-7 17-5
Southern Pine #2 9-4 12-4 14-8 17-2 8-6 11-0 13-1 15-5
Southern Pine #3 7-4 9-5 11-1 13-2 6-7 8-5 9-11 11-10
Spruce-Pine-Fir SS 9-2 12-1 15-5 18-9 9-2 12-1 15-0 17-5
Spruce-Pine-Fir #1 8-1 11-6 14-1 16-3 8-1 10-3 12-7 14-7
Spruce-Pine-Fir #2 18-1 11-6 14-1 16-3 8-1 10-3 12-7 14-7
Spruce-Pine-Fir #3 16-10 8-8 10-7 12-4 6-2 7-9 9-6 11-0

Check sources for availability of lumber in lengths greater than 20 feet.

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 47.8 N/m2 .

TABLE 2308.8(2)

FLOOR JOIST SPANS FOR COMMON LUMBER SPECIES

(Residential Living Areas, Live Load = 40 psf, L/ [DELTA]= 360)

JOIST SPACING (inches) SPECIES AND GRADE DEAD LOAD = 10 psf DEAD LOAD = 20 psf
2x6 2x8 2x10 2x12 2x6 2x8 2x10 2x12
Maximum floor joist spans
(ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.)
12 Douglas Fir-Larch SS 11-4 15-0 19-1 23-3 11-4 15-0 19-1 23-3
Douglas Fir-Larch #1 10-11 14-5 18-5 22-0 10-11 14-2 17-4 20-1
Douglas Fir-Larch #2 10-9 14-2 17-9 20-7 10-6 13-3 16-3 18-10
Douglas Fir-Larch #3 8-8 11-0 13-5 15-7 7-11 10-0 12-3 14-3
Hem-Fir SS 10-9 14-2 18-0 21-11 10-9 14-2 18-0 21-11
Hem-Fir #1 10-6 13-10 17-8 21-6 10-6 13-10 16-11 19-7
Hem-Fir #2 10-0 13-2 16-10 20-4 10-0 13-1 16-0 18-6
Hem-Fir #3 8-8 11-0 13-5 15-7 7-11 10-0 12-3 14-3
Southern Pine SS 11-2 14-8 18-9 22-10 11-2 14-8 18-9 22-10
Southern Pine #1 10-11 14-5 18-5 22-5 10-11 14-5 18-5 22-5
Southern Pine #2 10-9 14-2 18-0 21-9 10-9 14-2 16-11 19-10
Southern Pine #3 9-4 11-11 14-0 16-8 8-6 10-10 12-10 15-3
Spruce-Pine-Fir SS 10-6 13-10 17-8 21-6 10-6 13-10 17-8 21-6
Spruce-Pine-Fir #1 10-3 13-6 17-3 20-7 10-3 13-3 16-3 18-10
Spruce-Pine-Fir #2 10-3 13-6 17-3 20-7 10-3 13-3 16-3 18-10
Spruce-Pine-Fir #3 8-8 11-0 13-5 15-7 7-11 10-0 12-3 14-3
16 Douglas Fir-Larch SS 10-4 13-7 17-4 21-1 10-4 13-7 17-4 21-0
Douglas Fir-Larch #1 9-1 13-1 16-5 19-1 9-8 12-4 15-0 17-5
Douglas Fir-Larch #2 19-9 12-7 15-5 17-10 9-1 11-6 14-1 16-3
Douglas Fir-Larch #3 7-6 9-6 11-8 13-6 6-10 8-8 10-7 12-4
Hem-Fir SS 9-9 12-10 16-5 19-11 9-9 12-10 16-5 19-11
Hem-Fir #1 9-6 12-7 16-0 18-7 9-6 12-0 14-8 17-0
Hem-Fir #2 9-1 12-0 15-2 17-7 8-11 11-4 13-10 16-1
Hem-Fir #3 7-6 9-6 11-8 13-6 6-10 8-8 10-7 12-4
Southern Pine SS 10-2 13-4 17-0 20-9 10-2 13-4 17-0 20-9
Southern Pine #1 9-11 13-1 16-9 20-4 9-11 13-1 16-4 19-6
Southern Pine #2 9-9 12-10 16-1 18-10 9-6 12-4 14-8 17-2
Southern Pine #3 8-1 10-3 12-2 14-6 7-4 9-5 11-1 13-2
Spruce-Pine-Fir SS 9-6 12-7 16-0 19-6 9-6 12-7 16-0 19-6
Spruce-Pine-Fir #1 9-4 12-3 15-5 17-10 9-1 11-6 14-1 16-3
Spruce-Pine-Fir #2 9-4 12-3 15-5 17-10 9-1 11-6 14-1 16-3
Spruce-Pine-Fir #3 7-6 9-6 11-8 13-6 6-10 8-8 10-7 12-4
19.2 Douglas Fir-Larch SS 9-8 12-10 16-4 19-10 9-8 12-10 16-4 19-2
Douglas Fir-Larch #1 9-4 12-4 15-0 17-5 8-10 11-3 13-8 15-11
Douglas Fir-Larch #2 9-1 11-6 14-1 16-3 8-3 10-6 12-10 14-10
Douglas Fir-Larch #3 6-10 8-8 10-7 12-4 6-3 7-11 9-8 11-3
Hem-Fir SS 9-2 12-1 15-5 18-9 9-2 12-1 15-5 18-9
Hem-Fir #1 9-0 11-10 14-8 17-0 8-8 10-11 13-4 15-6
Hem-Fir #2 8-7 11-3 13-10 16-1 8-2 10-4 12-8 14-8
Hem-Fir #3 6-10 8-8 10-7 12-4 6-3 7-11 9-8 11-3
Southern Pine SS 9-6 12-7 16-0 19-6 9-6 12-7 16-0 19-6
Southern Pine #1 9-4 12-4 15-9 19-2 9-4 12-4 14-11 17-9
Southern Pine #2 9-2 12 -1 14-8 17-2 8-8 11-3 13-5 15-8
Southern Pine #3 7-4 9-5 11-1 13-2 6-9 8-7 10-1 12-1
Spruce-Pine-Fir SS 9-0 11-10 15-1 18-4 9-0 11-10 15-1 17-9
Spruce-Pine-Fir #1 8-9 11-6 14-1 16-3 8-3 10-6 12-10 14-10
Spruce-Pine-Fir #2 8-9 11-6 14-1 16-3 8-3 10-6 12-10 14-10
Spruce-Pine-Fir #3 6-10 8-8 10-7 12-4 6-3 7-11 9-8 11-3
24 Douglas Fir-Larch SS 9-0 11-11 15-2 18-5 9-0 11-11 14-9 17-1
Douglas Fir-Larch #1 8-8 11-0 13-5 15-7 7-11 10-0 12-3 14-3
Douglas Fir-Larch #2 8-1 10-3 12-7 14-7 7-5 9-5 11-6 13-4
Douglas Fir-Larch #3 6-2 7-9 9-6 11-0 5-7 7-1 8-8 10-1
  Hem-Fir SS 8-6 11-3 14-4 17-5 8-6 11-3 14-4 16-10a
Hem-Fir #1 8-4 10-9 13-1 15-2 7-9 9-9 11-11 13-10
Hem-Fir #2 7-11 10-2 12-5 14-4 7-4 9-3 11-4 13-1
Hem-Fir #3 6-2 7-9 9-6 11-0 5-7 7-1 8-8 10-1
Southern Pine SS 8-10 11-8 14-11 18-1 8-10 11-8 14-11 18-1
Southern Pine #1 8-8 11-5 14-7 17-5 8-8 11-3 13-4 15-11
Southern Pine #2 8-6 11-0 13-1 15-5 7-9 10-0 12-0 14-0
Southern Pine #3 6-7 8-5 9-11 11-10 6-0 7-8 9-1 10-9
Spruce-Pine-Fir SS 8-4 11-0 14-0 17-0 8-4 11-0 13-8 15-11
Spruce-Pine-Fir #1 8-1 10-3 12-7 14-7 7-5 9-5 11-6 13-4
pruce-Pine-Fir #2 8-1 10-3 12-7 14-7 7-5 9-5 11-6 13-4
Spruce-Pine-Fir #3 6-2 7-9 9-6 11-0 5-7 7-1 8-8 10-1

Check sources for availability of lumber in lengths greater than 20 feet.

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 47.8 N/m2 .

a. End bearing length shall be increased to 2 inches.

2308.8.5 Lateral support. Floor, attic and roof framing with a nominal depth-to-thickness ratio greater than or equal to 5:1 shall have one edge held in line for the entire span. Where the nominal depth-to-thickness ratio of the framing member exceeds 6:1, there shall be one line of bridging for each 8 feet (2438 mm) of span, unless both edges of the member are held in line. The bridging shall consist of not less than 1-inch by 3-inch (25 mm by 76 mm) lumber, double nailed at each end, of equivalent metal bracing of equal rigidity, full-depth solid blocking or other approved means. A line of bridging shall also be required at supports where equivalent lateral support is not otherwise provided.

2308.8.6 Structural floor sheathing. Structural floor sheathing shall comply with the provisions of Section 2304.7.1.

2308.8.7 Under-floor ventilation. For under-floor ventilation, see Section 1203.3.

2308.9 Wall framing.

2308.9.1 Size, height and spacing. The size, height and spacing of studs shall be in accordance with Table 2308.9.1 except that utility-grade studs shall not be spaced more than 16 inches (406 mm) o.c., or support more than a roof and ceiling, or exceed 8 feet (2438 mm) in height for exterior walls and load-bearing walls or 10 feet (3048 mm) for interior nonload-bearing walls. Studs shall be continuous from a support at the sole plate to a support at the top plate to resist loads perpendicular to the wall. The support shall be a foundation or floor, ceiling or roof diaphragm or shall be designed in accordance with accepted engineering practice.

Exception: Jack studs, trimmer studs and cripple studs at openings in walls that comply with Table 2308.9.5.

2308.9.2 Framing details. Studs shall be placed with their wide dimension perpendicular to the wall. Not less than three studs shall be installed at each corner of an exterior wall.

Exception: At corners, two studs are permitted, provided wood spacers orbackup cleats of 3/8-inch-thick ( 9.5 mm) wood structural panel, 3/8-inch ( 9.5 mm) Type M "Exterior Glue" particleboard, 1-inch-thick (25 mm) lumber or other approved devices that will serve as an adequate backing for the attachment of facing materials are used. Where fire-resistance ratings or shear values are involved, wood spacers, backup cleats or other devices shall not be used unless specifically approved for such use.

2308.9. 2.1 Top plates. Bearing and exterior wall studs shall be capped with double top plates installed to provide overlapping at corners and at intersections with other partitions. End joints in double top plates shall be offset at least 48 inches (1219 mm), and shall be nailed with not less than eight 16d face nails on each side of the joint. Plates shall be a nominal 2 inches (51 mm) in depth and have a width at least equal to the width of the studs.

Exception: A single top plate is permitted, provided the plate is adequately tied at joints, corners and intersecting walls by at least the equivalent of 3-inch by 6-inch (76 mm by 152 mm) by 0.036 -inch-thick ( 0.914 mm) galvanized steel that is nailed to each wall or segment of wall by six 8d nails or equivalent, provided the rafters, joists or trusses are centered over the studs with a tolerance of no more than 1 inch (25 mm).

2308.9. 2.2 Top plates for studs spaced at 24 inches (610 mm). Where bearing studs are spaced at 24-inch (610 mm) intervals and top plates are less than two 2-inch by 6-inch (51 mm by 152 mm) or two 3-inch by 4-inch (76 mm by 102 mm) members and where the floor joists, floor trusses or roof trusses that they support are spaced at more than 16-inch (406 mm) intervals, such joists or trusses shall bear within 5 inches (127 mm) of the studs beneath or a third plate shall be installed.

2308.9. 2.3 Nonbearing walls and partitions. In nonbearing walls and partitions, studs shall be spaced not more than 28 inches (711 mm) o.c. and are permitted to be set with the long dimension parallel to the wall. Interior nonbearing partitions shall be capped with no less than a single top plate installed to provide overlapping at corners and at intersections with other walls and partitions. The plate shall be continuously tied at joints by solid blocking at least 16 inches (406 mm) in length and equal in size to the plate or by ½-inch by 1 ½-inch ( 12.7 mm by 38 mm) metal ties with spliced sections fastened with two 16d nails on each side of the joint.

TABLE 2308.9.1 SIZE, HEIGHT AND SPACING OF WOOD STUDS

STUDSIZE(inches) BEARING WALLS NONBEARING WALLS
Laterally unsupported stud heighta (feet) Supporting roof and ceiling only Supporting one floor, roof and ceiling Supporting two floors, Roof and ceiling Laterallyunsupportedstud heighta(feet) Spacing (inches)
Spacing (inches)
2 x 3b - - - - 10 16
2 x 4 10 24 16 - 14 24
3 x 4 10 24 24 16 14 24
2 x 5 10 24 24 - 16 24
2 x 6 10 24 24 16 20 24

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

a. Listed heights are distances between points of lateral support placed perpendicular to the plane of the wall. Increases in unsupported height are permitted where justified by an analysis.

b. Shall not be used in exterior walls.

2308.9. 2.4 Plates or sills. Studs shall have full bearing on a plate or sill not less than 2 inches (51 mm) in thickness having a width not less than that of the wall studs.

2308.9.3 Bracing. Braced wall lines shall consist of braced wall panels that meet the requirements for location, type and amount of bracing as shown in Figure 2308.9.3, specified in Table 2308.9.3(1) and are in line or offset from each other by not more than 4 feet (1219 mm). Braced wall panels shall start not more than 12½ feet (3810 mm) from each end of a braced wall line. Braced wall panels shall be clearly indicated on the plans. Construction of braced wall panels shall be by one of the following methods:

1. Nominal 1-inch by 4-inch (25 mm by 102 mm) continuous diagonal braces let into top and bottom plates and intervening studs, placed at an angle not more than 60 degrees ( 1.0 rad) or less than 45 degrees ( 0.79 rad) from the horizontal and attached to the framing in conformance with Table 2304.9.1.

2. Wood boards of 5/8 inch ( 15.9 mm) net minimum thickness applied diagonally on studs spaced not over 24 inches (610 mm) o.c.

3. Wood structural panel sheathing with a thickness not less than3/8 inch ( 9.5 mm) for 16-inch (406 mm) or 24-inch (610 mm) stud spacing in accordance with Tables 2308.9.3(2) and 2308.9.3(3).

4. Fiberboard sheathing panels not less than ½ inch ( 12.7 mm) thick applied vertically or horizontally on studs spaced not over 16 inches (406 mm) o.c. where installed with fasteners in accordance with Section 2306.6 and Table 2306.6.

5. Gypsum board [sheathing ½-inch-thick ( 12.7 mm) by 4-feet-wide (1219 mm) wallboard or veneer base] on studs spaced not over 24 inches (610 mm) o.c. and nailed at 7 inches (178 mm) o.c. with nails as required by Table 2306.7.

6. Particleboard wall sheathing panels where installed in accordance with Table 2308.9.3(4).

7. Portland cement plaster on studs spaced 16 inches (406 mm) o.c. installed in accordance with Section 2510.

8. Hardboard panel siding where installed in accordance with Section 2303.1.6 and Table 2308.9.3(5).

For cripple wall bracing, see Section 2308.9. 4.1. For Methods 2, 3, 4, 6, 7 and 8, each panel must be at least 48 inches (1219 mm) in length, covering three stud spaces where studs are spaced 16 inches (406 mm) apart and covering two stud spaces where studs are spaced 24 inches (610 mm) apart. For Method 5, each panel must be at least 96 inches (2438 mm) in length where applied to one face of a panel and 48 inches (1219 mm) where applied to both faces. All vertical joints of panel sheathing shall occur over studs and adjacent panel joints shall be nailed to common framing members. Horizontal joints shall occur over blocking or other framing equal in size to the studding except where waived by the installation requirements for the specific sheathing materials. Sole plates shall be nailed to the floor framing and top plates shall be connected to the framing above in accordance with Section 2308.3.2. Where joists are perpendicular to braced wall lines above, blocking shall be provided under and in line with the braced wall panels.

2308.9. 3.1 Alternative bracing. Any bracing required by Section 2308.9.3 is permitted to be replaced by the following:

1. In one-story buildings, each panel shall have a length of not less than 2 feet 8 inches (813 mm) and a height of not more than 10 feet (3048mm). Each panel shall be sheathed on one face with 3 /8-inch-minimum-thickness ( 9.5 mm) wood structural panel sheathing nailed with 8d common or galvanized box nails in accordance with Table 2304.9.1 and blocked at wood structural panel edges. Two anchor bolts installed in accordance with Section 2308.6 shall be provided in each panel. Anchor bolts shall be placed at each panel outside quarter points. Each panel end stud shall have a tie-down device fastened to the foundation, capable of providing an approved uplift capacity of not less than 1,800 pounds (8006 N). The tie-down device shall be installed in accordance with the manufacturer's recommendations. The panels shall be supported directly on a foundation or on floor framing supported directly on a foundation that is continuous across the entire length of the braced wall line. This foundation shall be reinforced with not less than one No. 4 bar top and bottom.

Where the continuous foundation is required to have a depth greater than 12 inches (305 mm), a minimum 12-inch by 12-inch (305 mm by 305 mm) continuous footing or turned down slab edge is permitted at door openings in the braced wall line. This continuous footing or turned down slab edge shall be reinforced with not less than one No. 4 bar top and bottom. This reinforcement shall be lapped 15 inches (381 mm) with the reinforcement required in the continuous foundation located directly under the braced wall line.

2. In the first story of two-story buildings, each wall panel shall be braced in accordance with Section 2308.9. 3.1, Item 1, except that the wood structural panel sheathing shall be provided on both faces, three anchor bolts shall be placed at one-quarter points, and tie-down device uplift capacity shall not be less than 3,000 pounds (13 344 N).

SEISMIC DESIGN CATEGORY MAXIMUM WALL SPACING (feet) REQUIRED BRACING LENGTH, b
A, B and C 35'-0" Table 2308.9.3(1) and Section 2308.9.3
D and E 25'-0" Table 2308.12.4

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-5.jpg

FIGURE 2308.9.3

BASIC COMPONENTS OF THE LATERAL BRACING SYSTEM

TABLE 2308.9.3(1)

BRACED WALL PANELSa

SEISMICDESIGNCATEGORY CONDITION CONSTRUCTIONMETHODSb,c BRACED PANEL LOCATION ANDLENGTHd
1 2 3 4 5 6 7 8
A and B One story, top of two or three story X X X X X X X X Located inaccordance withSection 2308.9.3 andnot more than 25 feeton center.
First story of twostory or second storyof three story X X X X X X X X
First story of three story - X X X Xe X X X
C One story or top of two story - X X X X X X X Located inaccordance withSection 2308.9.3 andnot more than 25 feeton center.
First story of two story - X X X Xe X X X Located inaccordance withSection 2308.9.3 andnot more than 25 feeton center, but totallength shall not beless than 25% ofbuilding lengthf .

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

a. This table specifies minimum requirements for braced panels that form interior or exterior braced wall lines.

b. See Section 2308.9.3 for full description.

c. See Sections 2308.9. 3.1 and 2308.9. 3.2 for alternative braced panel requirements.

d. Building length is the dimension parallel to the braced wall length.

e. Gypsum wallboard applied to framing supports that are spaced at 16 inches on center.

f. The required lengths shall be doubled for gypsum board applied to only one face of a braced wall panel.

TABLE 2308.9.3(2)

EXPOSED PLYWOOD PANEL SIDING

MINIMUM THICKNESSa (inch) MINIMUM NUMBER OF PLIES STUD SPACING(inches)Plywood siding applied directlyto studs or over sheathing
3/8 3 16b
1/2 4 24

For SI: 1 inch = 25.4 mm.

a. Thickness of grooved panels is measured at bottom of grooves.

b. Spans are permitted to be 24 inches if plywood siding applied with face grain perpendicular tostuds or over one of the following: (1) 1-inch board sheathing, (2) 7/16 -inch wood structuralpanel sheathing or (3) 3 /8- inch wood structural panel sheathing with strength axis (which is the long direction of the panel unless otherwise marked) of sheathing perpendicular to studs.

TABLE 2308.9.3(3)

WOOD STRUCTURAL PANEL WALL SHEATHINGb

(Not Exposed to the Weather, Strength Axis Parallel or Perpendicular to Studs Except as Indicated Below)

MINIMUM THICKNESS (inch) PANEL SPAN RATING STUD SPACING (inches)
Siding nailed to studs Nailable sheathing
Sheathing parallel to studs Sheathing perpendicular to studs
3/8, 15/32, 1/2 16/0, 20/0, 24/0, 32/16 Wall-24" o.c. 24 16 24
7/16, 15/32, 1/2 24/0, 24/16, 32/16 Wall-24' o.c. 24 24a 24

For SI: 1 inch = 25.4 mm.

a. Plywood shall consist of four or more plies.

b. Blocking of horizontal joints shall not be required except as specified in Sections 2306.3 and 2308.12.4.

TABLE 2308.9.3(4)

ALLOWABLE SPANS FOR PARTICLEBOARD WALL SHEATHING

(Not Exposed to the Weather, Long Dimension of the Panel Parallel or

Perpendicular to Studs)

GRADE THICKNESS (inch) STUD SPACING (inches)
Siding nailed to studs Sheathing under coverings specified in Section 2308.9.3 parallel or perpendicular to studs
M-S "Exterior Glue" 3/8 16 -
and M-2"Exterior Glue" 1/2 16 16

For SI: 1 inch = 25.4 mm.

TABLE 2308.9.3(5)

HARDBOARD SIDING

SIDING MINIMUMNOMINALTHICKNESS(inch) 2 *4FRAMINGMAXIMUMSPACING NAILSIZEa, b, d NAIL SPACING
General Bracing panelsc
1. Lap siding
Direct to studs 3/8 16" o.c. 8d 16" o.c. Not applicable
Over sheathing 3/8 16" o.c. 10d 16" o.c. Not applicable
2. Square edge panel siding
Direct to studs 3/8 24"o.c. 6d 6"o.c. edges; 12" o.c. at intermediate supports 4" o.c. edges; 8" o.c. at intermediate supports
Over sheathing 3/8 24"o.c. 8d 6" o.c. edges; 12" o.c. at intermediate supports 4" o.c. edges; 8" o.c. at intermediate supports
3. Shiplap edge panel siding
Direct to studs 3/8 16" o.c. 6d 6" o.c. edges; 12" o.c. at intermediate supports 4" o.c. edges; 8" o.c. at intermediate supports
Over sheathing 3/8 16" o.c. 8d 6" o.c. edges; 12" o.c. at intermediate supports 4" o.c. edges; 8" o.c. at intermediate supports

For SI: 1 inch = 25.4 mm.

a. Nails shall be corrosion resistant.

b. Minimum acceptable nail dimensions:

c. Where used to comply with Section 2308.9.3.

d. Nail length must accommodate the sheathing and penetrate framing 1 ½ inches.

   Panel Siding (inch) Lap Siding (inch)
Shank diameter 0.092 0.099
Head diameter 0.225 0.240

2308.9. 3.2 Alternate bracing wall panel adjacent to a door or window opening. Any bracing required by Section 2308.9.3 is permitted to be replaced by the following when used adjacent to a door or window opening with a full-length header:

1. In one-story buildings, each panel shall have a length of not less than 16 inches (406 mm) and a height of not more than 10 feet (3048 mm). Each panel shall be sheathed on one face with a single layer of 3 /8 inch ( 9.5 mm) minimum thickness wood structural panel sheathing nailed with 8d common or galvanized box nails in accordance with Figure 2308.9. 3.2. The wood structural panel sheathing shall extend up over the solid sawn or glued-laminated header and shall be nailed in accordance with Figure 2308.9. 3.2. A built-up header consisting of at least two 2 * 12s and fastened in accordance with Item 24 of Table 2304.9.1 shall be permitted to be used. A spacer, if used, shall be placed on the side of the built-up beam opposite the wood structural panel sheathing. The header shall extend between the inside faces of the first full-length outer studs of each panel. The clear span of the header between the inner studs of each panel shall be not less than 6 feet (1829 mm) and not more than 18 feet (5486 mm) in length. A strap with an uplift capacity of not less than 1,000 pounds (4,400 N) shall fasten the header to the inner studs opposite the sheathing. One anchor bolt not less than 5/8 inch ( 15.9 mm) diameter and installed in accordance with Section 2308.6 shall be provided in the center of each sill plate. The studs at each end of the panel shall have a tie-down device fastened to the foundation with an uplift capacity of not less than 4,200 pounds (18 480 N).

Where a panel is located on one side of the opening, the header shall extend between the inside face of the first full-length stud of the panel and the bearing studs at the other end of the opening. A strap with an uplift capacity of not less than 1,000 pounds (4400 N) shall fasten the header to the bearing studs. The bearing studs shall also have a tie-down device fastened to the foundation with an uplift capacity of not less than 1,000 pounds (4400 N).

The tie-down devices shall be an embedded strap type, installed in accordance with the manufacturer's recommendations. The panels shall be supported directly on a foundation that is continuous across the entire length of the braced wall line. This foundation shall be reinforced with not less than one No. 4 bar top and bottom. Where the continuous foundation is required to have a depth greater than 12 inches (305 mm), a minimum 12-inch by 12-inch (305 mm by 305 mm) continuous footing or turned down slab edge is permitted at door openings in the braced wall line. This continuous footing or turned down slab edge shall be reinforced with not less than one No. 4 bar top and bottom. This reinforcement shall be lapped not less than 15 inches (381 mm) with the reinforcement required in the continuous foundation located directly under the braced wall line.

2. In the first story of two-story buildings, each wall panel shall be braced in accordance with Item 1 above, except that each panel shall have a length of not less than 24 inches (610 mm).

For SI: 1 foot = 304.8 mm; 1 inch = 25.4 mm; 1 pound = 4.448 N.

FIGURE 2308.9. 3.2

ALTERNATE BRACED WALL PANEL ADJACENT TO A DOOR OR

WINDOW OPENING

2308.9.4 Cripple walls. Foundation cripple walls shall be framed of studs not less in size than the studding above with a minimum length of 14 inches (356 mm), or shall be framed of solid blocking. Where exceeding 4 feet (1219 mm) in height, such walls shall be framed of studs having the size required for an additional story.

2308.9. 4.1 Bracing. For the purposes of this section, cripple walls having a stud height exceeding 14 inches (356 mm) shall be considered a story and shall be braced in accordance with Table 2308.9.3(1) for Seismic Design Category A, B or C. See Section 2308.12.4 for Seismic Design Category D or E.

2308.9. 4.2 Nailing of bracing. Spacing of edge nailing for required wall bracing shall not exceed 6 inches (152 mm) o.c. along the foundation plate and the top plate of the cripple wall. Nail size, nail spacing for field nailing and more restrictive boundary nailing requirements shall be as required elsewhere in the code for the specific bracing material used.

2308.9.5 Openings in exterior walls.

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-6.jpg

2308.9. 5.1 Headers. Headers shall be provided over each opening in exterior-bearing walls. Headers shall be designed in accordance with Section 2301.2, Item 1 or 2. Headers shall be of two pieces of nominal 2-inch (51 mm) framing lumber set on edge as permitted by Table 2308.9.5 and nailed together in accordance with Table 2304.9.1 or of solid lumber of equivalent size.

2308.9. 5.2 Header support. Wall studs shall support the ends of the header in accordance with Table 2308.9.5. Each end of a lintel or header shall have a length of bearing of not less than 1½ inches (38 mm) for the full width of the lintel.

2308.9.6 Openings in interior bearing partitions. Headers shall be provided over each opening in interior bearing partitions as required in Section 2308.9.5. The spans in Table 2308.9.6 are permitted to be used. Wall studs shall support the ends of the header in accordance with Table 2308.9.5 or 2308.9.6, as appropriate.

2308.9.7 Openings in interior nonbearing partitions.

Openings in nonbearing partitions are permitted to be framed with single studs and headers. Each end of a lintel or header shall have a length of bearing of not less than 1½ inches (38 mm) for the full width of the lintel.

2308.9.8 Pipes in walls. Stud partitions containing plumbing, heating or other pipes shall be so framed and the joists underneath so spaced as to give proper clearance for the piping. Where a partition containing such piping runs parallel to the floor joists, the joists underneath such partitions shall be doubled and spaced to permit the passage of such pipes and shall be bridged. Where plumbing, heating or other pipes are placed in or partly in a partition, necessitating the cutting of the soles or plates, a metal tie not less than 0.058 inch ( 1.47 mm) (16 galvanized gage) and 1½ inches (38 mm) wide shall be fastened to each plate across and to each side of the opening with not less than six 16d nails.

2308.9.9 Bridging. Unless coveredbyinterioror exterior wall coverings or sheathing meeting the minimum requirements of this code, stud partitions or walls with studs having a height-to-least-thickness ratio exceeding 50 shall have bridging not less than 2 inches (51 mm) in thickness and of the same width as the studs fitted snugly and nailed thereto to provide adequate lateral support. Bridging shall be placed in every stud cavity and at a frequency such that no stud so braced shall have a height-to-least-thickness ratio exceeding 50 with the height of the stud measured between horizontal framing and bridging or between bridging, whichever is greater.

2308.9.10 Cutting and notching. In exterior walls and bearing partitions, any wood stud is permitted to be cut or notched to a depth not exceeding 25 percent of its width. Cutting or notching of studs to a depth not greater than 40 percent of the width of the stud is permitted in nonbearing partitions supporting no loads other than the weight of the partition.

2308.9.11 Bored holes. A hole not greater in diameter than 40 percent of the stud width is permitted to be bored in any wood stud. Bored holes not greater than 60 percent of the width of the stud are permitted in nonbearing partitions or in any wall where each bored stud is doubled, provided not more than two such successive doubled studs are so bored.

In no case shall the edge of the bored hole be nearer than 5/8 inch ( 15.9 mm) to the edge of the stud.

Bored holes shall not be located at the same section of stud as a cut or notch.

2308.10 Roof and ceiling framing. The framing details required in this section apply to roofs having a minimum slope of three units vertical in 12 units horizontal (25-percent slope) or greater. Where the roof slope is less than three units vertical in 12 units horizontal (25-percent slope), members supporting rafters and ceiling joists such as ridge board, hips and valleys shall be designed as beams.

2308.10.1 Wind uplift. The roof construction shall have rafter and truss ties to the wall below. Resultant uplift loads shall be transferred to the foundation using a continuous load path. The rafter or truss to wall connection shall comply with Tables 2304.9.1 and 2308.10.1.

TABLE 2308.9.5

HEADER AND GIRDER SPANSa FOR EXTERIOR BEARING WALLS

(Maximum Spans for Douglas Fir-Larch, Hem-Fir, Southern Pine and

Spruce-Pine-Firb and Required Number of Jack Studs)

HEADERS SUPPORTING SIZE GROUND SNOW LOAD (psf)e
30 50
Building widthc (feet)
20 28 36 20 28 36
Span NJ d Span NJ d Span NJ d Span NJ d Span NJ d Span NJ d
Roof & Ceiling 2-2 x 4 3-6 1 3-2 1 2-10 1 3-2 1 2-9 1 2-6 1
2-2 x 6 5-5 1 4-8 1 4-2 1 4-8 1 4-1 1 3-8 2
2-2 x 8 6-10 1 5-11 2 5-4 2 5-11 2 5-2 2 4-7 2
2-2 x 10 8-5 2 7-3 2 6-6 2 7-3 2 6-3 2 5-7 2
2-2 x 12 9-9 2 8-5 2 7-6 2 8-5 2 7-3 2 6-6 2
3-2 x 8 8-4 1 7-5 1 6-8 1 7-5 1 6-5 2 5-9 2
3-2 x 10 10-6 1 9-1 2 8-2 2 9-1 2 7-10 2 7-0 2
3-2 x 12 12-2 2 10-7 2 9-5 2 10-7 2 9-2 2 8-2 2
4-2 x 8 9-2 1 8-4 1 7-8 1 8-4 1 7-5 1 6-8 1
4-2 x 10 11-8 1 10-6 1 9-5 2 10-6 1 9-1 2 8-2 2
   4-2 x 12 14-1 1 12-2 2 10-11 2 12-2 2 10-7 2 9-5 2
Roof, Ceiling &1Center-BearingFloor 2-2 x 4 3-1 1 2-9 1 2-5 1 2-9 1 2-5 1 2-2 1
2-2 x 6 4-6 1 4-0 1 3-7 2 4-1 1 3-7 2 3-3 2
2-2 x 8 5-9 2 5-0 2 4-6 2 5-2 2 4-6 2 4-1 2
2-2 x 10 7-0 2 6-2 2 5-6 2 6-4 2 5-6 2 5-0 2
2-2 x 12 8-1 2 7-1 2 6-5 2 7-4 2 6-5 2 5-9 3
3-2 x 8 7-2 1 6-3 2 5-8 2 6-5 2 5-8 2 5-1 2
3-2 x 10 8-9 2 7-8 2 6-11 2 7-11 2 6-11 2 6-3 2
3-2 x 12 10-2 2 8-11 2 8-0 2 9-2 2 8-0 2 7-3 2
4-2 x 8 8-1 1 7-3 1 6-7 1 7-5 1 6-6 1 5-11 2
4-2 x 10 10-1 1 8-10 2 8-0 2 9-1 2 8-0 2 7-2 2
4-2 x 12 11-9 2 10-3 2 9-3 2 10-7 2 9-3 2 8-4 2
Roof, Ceiling &1 Clear SpanFloor 2-2 x 4 2-8 1 2-4 1 2-1 1 2-7 1 2-3 1 2-0 1
2-2 x 6 3-11 1 3-5 2 3-0 2 3-10 2 3-4 2 3-0 2
2-2 x 8 5-0 2 4-4 2 3-10 2 4-10 2 4-2 2 3-9 2
2-2 x 10 6-1 2 5-3 2 4-8 2 5-11 2 5-1 2 4-7 3
2-2 x 12 7-1 2 6-1 3 5-5 3 6-10 2 5-11 3 5-4 3
3-2 x 8 6-3 2 5-5 2 4-10 2 6-1 2 5-3 2 4-8 2
3-2 x 10 7-7 2 6-7 2 5-11 2 7-5 2 6-5 2 5-9 2
3-2 x 12 8-10 2 7-8 2 6-10 2 8-7 2 7-5 2 6-8 2
4-2 x 8 7-2 1 6-3 2 5-7 2 7-0 1 6-1 2 5-5 2
4-2 x 10 8-9 2 7-7 2 6-10 2 8-7 2 7-5 2 6-7 2
4-2 x 12 10-2 2 8-10 2 7-11 2 9-11 2 8-7 2 7-8 2
Roof, Ceiling &2Center-BearingFloors 2-2 x 4 2-7 1 2-3 1 2-0 1 2-6 1 2-2 1 1-11 1
2-2 x 6 3-9 2 3-3 2 2-11 2 3-8 2 3-2 2 2-10 2
2-2 x 8 4-9 2 4-2 2 3-9 2 4-7 2 4-0 2 3-8 2
2-2 x 10 5-9 2 5-1 2 4-7 3 5-8 2 4-11 2 4-5 3
2-2 x 12 6-8 2 5-10 3 5-3 3 6-6 2 5-9 3 5-2 3
3-2 x 8 5-11 2 5-2 2 4-8 2 5-9 2 5-1 2 4-7 2
3-2 x 10 7-3 2 6-4 2 5-8 2 7-1 2 6-2 2 5-7 2
3-2 x 12 8-5 2 7-4 2 6-7 2 8-2 2 7-2 2 6-5 3
4-2 x 8 6-10 1 6-0 2 5-5 2 6-8 1 5-10 2 5-3 2
4-2 x 10 8-4 2 7-4 2 6-7 2 8-2 2 7-2 2 6-5 2
4-2 x 12 9-8 2 8-6 2 7-8 2 9-5 2 8-3 2 7-5 2
Roof, Ceiling &2Clear SpanFloors 2-2 x 4 2-1 1 1-8 1 1-6 2 2-0 1 1-8 1 1-5 2
2-2 x 6 3-1 2 2-8 2 2-4 2 3-0 2 2-7 2 2-3 2
  2-2 x 8 3-10 2 3-4 2 3-0 3 3-10 2 3-4 2 2-11 3
2-2 x 10 4-9 2 4-1 3 3-8 3 4-8 2 4-0 3 3-7 3
2-2 x 12 5-6 3 4-9 3 4-3 3 5-5 3 4-8 3 4-2 3
3-2 x 8 4-10 2 4-2 2 3-9 2 4-9 2 4-1 2 3-8 2
3-2 x 10 5-11 2 5-1 2 4-7 3 5-10 2 5-0 2 4-6 3
3-2 x 12 6-10 2 5-11 3 5-4 3 6-9 2 5-10 3 5-3 3
4-2 x 8 5-7 2 4-10 2 4-4 2 5-6 2 4-9 2 4-3 2
4-2 x 10 6-10 2 5-11 2 5-3 2 6-9 2 5-10 2 5-2 2
4-2 x 12 7-11 2 6-10 2 6-2 3 7-9 2 6-9 2 6-0 3

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 47.8 N/m2 .

a. Spans are given in feet and inches (ft-in).

b. Tabulated values are for No. 2 grade lumber.

c. Building width is measured perpendicular to the ridge. For widths between those shown, spans are permitted to be interpolated.

d. NJ -Number of jack studs required to support each end. Where the number of required jack studs equals one, the header is permitted to be supported by an approved framing anchor attached to the full-height wall stud and to the header.

e. Use 30 pounds per square foot ground snow load for cases in which ground snow load is less than 30 pounds per square foot and the roof live load is equal to or less than 20 pounds per square foot.

TABLE 2308.9.6

HEADER AND GIRDER SPANSa FOR INTERIOR BEARING WALLS

(Maximum Spans for Douglas Fir-Larch, Hem-Fir, Southern Pine and Spruce-Pine-

Firb and Required Number of Jack Studs)

HEADERS ANDGIRDERS SUPPORTING SIZE BUILDING WIDTHc (feet)
20 28 36
Span NJd Span NJd Span NJd
One Floor Only 2-2 x 4 3-1 1 2-8 1 2-5 1
2-2 x 6 4-6 1 3-11 1 3-6 1
2-2 x 8 5-9 1 5-0 2 4-5 2
2-2 x10 7-0 2 6-1 2 5-5 2
2-2 x12 8-1 2 7-0 2 6-3 2
3-2 x 8 7-2 1 6-3 1 5-7 2
3-2 x10 8-9 1 7-7 2 6-9 2
3-2 x12 10-2 2 8-10 2 7-10 2
4-2 x 8 9-0 1 7-8 1 6-9 1
  4-2 x10 10-1 1 8-9 1 7-10 2
4-2 x12 11-9 1 10-2 2 9-1 2
Two Floors 2-2 x 4 2-2 1 1-10 1 1-7 1
2-2 x 6 3-2 2 2-9 2 2-5 2
2-2 x 8 4-1 2 3-6 2 3-2 2
2-2 x10 4-11 2 4-3 2 3-10 3
2-2 x12 5-9 2 5-0 3 4-5 3
3-2 x 8 5-1 2 4-5 2 3-11 2
3-2 x10 6-2 2 5-4 2 4-10 2
3-2 x12 7-2 2 6-3 2 5-7 3
4-2 x 8 6-1 1 5-3 2 4-8 2
4-2 x10 7-2 2 6-2 2 5-6 2
4-2 x12 8-4 2 7-2 2 6-5 2

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

a. Spans are given in feet and inches (ft-in).

b. Tabulated values are for No. 2 grade lumber.

c. Building width is measured perpendicular to the ridge. For widths between those shown, spans are permitted to be interpolated.

d. NJ -Number of jack studs required to support each end. Where the number of required jack studs equals one, the headers are permitted to be supported by an approved framing anchor attached to the full-height wall stud and to the header.

TABLE 2308.10.1

REQUIRED RATING OF APPROVED UPLIFT CONNECTORS (pounds)a,

b, c, e, f, g, h

BASIC WINDSPEED (3-second gust) ROOF SPAN (feet) OVERHANGS(pounds/feet)d
12 20 24 28 32 36 40
85 -72 -120 -145 -169 -193 -217 -241 - 38.55
90 -91 -151 -181 -212 -242 -272 -302 - 43.22
100 -131 -281 -262 -305 -349 -393 -436 - 53.36
110 -175 -292 -351 -409 -467 -526 -584 - 64.56

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 1.61 km/hr, 1 pound = 0.454 Kg, 1 pound/foot = 14.5939 N/m.

a. The uplift connection requirements are based on a 30-foot mean roof height located in Exposure B. For Exposure C or D and for other mean roof heights, multiply the above loads by the adjustment coefficients below.

   Mean Roof Height (feet)
EXPOSURE 15 20 25 30 35 40 45 50 55 60
B 1.00 1.00 1.00 1.00 1.05 1.09 1.12 1.16 1.19 1.22
C 1.21 1.29 1.35 1.40 1.45 1.49 1.53 1.56 1.59 1.62
D 1.47 1.55 1.61 1.66 1.70 1.74 1.78 1.81 1.84 1.87

b. The uplift connection requirements are based on the framing being spaced 24 inches on center. Multiply by 0.67 for framing spaced 16 inches on center and multiply by 0.5 for framing spaced 12 inches on center.

c. The uplift connection requirements include an allowance for 10 pounds of dead load.

d. The uplift connection requirements do not account for the effects of overhangs. The magnitude of the above loads shall be increased by adding the overhang loads found in the table. The overhang loads are also based on framing spaced 24 inches on center. The overhang loads given shall be multiplied by the overhang projection and added to the roof uplift value in the table.

e. The uplift connection requirements are based upon wind loading on end zones as defined in Figure 6-2 of ASCE 7. Connection loads for connections located a distance of 20 percent of the least horizontal dimension of the building from the corner of the building are permitted to be reduced by multiplying the table connection value by 0.7 and multiplying the overhang load by 0.8.

f. For wall-to-wall and wall-to-foundation connections, the capacity of the uplift connector is permitted to be reduced by 100 pounds for each full wall above. (For example, if a 500-pound rated connector is used on the roof framing, a 400-pound rated connector is permitted at the next floor level down).

g. Interpolation is permitted for intermediate values of basic wind speeds and roof spans.

h. The rated capacity of approved tie-down devices is permitted to include up to a 60-percent increase for wind effects where allowed by material specifications.

2308.10.2 Ceiling joist spans. Allowable spans for ceiling joists shall be in accordance with Table 2308.10.2(1) or 2308.10.2(2). For other grades and species, refer to the AF&PA Span Tables for Joists and Rafters.

2308.10.3 Rafter spans. Allowable spans for rafters shall be in accordance with Table 2308.10.3(1), 2308.10.3(2), 2308.10.3(3), 2308.10.3(4), 2308.10.3(5) or 2308.10.3(6). For other grades and species, refer to the AF&PA Span Tables for Joists and Rafters.

2308.10.4 Ceiling joist and rafter framing. Rafters shall be framed directly opposite each other at the ridge. There shall be a ridge board at least 1-inch (25 mm) nominal thickness at ridges and not less in depth than the cut end of the rafter. At valleys and hips, there shall be a single valley or hip rafter not less than 2-inch (51 mm) nominal thickness and not less in depth than the cut end of the rafter.

2308.10. 4.1 Ceiling joist and rafter connections. Ceiling joists and rafters shall be nailed to each other and the assembly shall be nailed to the top wall plate in accordance with Tables 2304.9.1 and 2308.10.1. Ceiling joists shall be continuous or securely joined where they meet over interior partitions and fastened to adjacent rafters in accordance with Tables 2308.10. 4.1 and 2304.9.1 to provide a continuous rafter tie across the building where such joists are parallel to the rafters. Ceiling joists shall have a bearing surface of not less than 1½ inches (38 mm) on the top plate at each end.

Where ceiling joists are not parallel to rafters, an equivalent rafter tie shall be installed in a manner to provide a continuous tie across the building, at a spacing of not more than 4 feet (1219 mm) o.c. The connections shall be in accordance with Tables 2308.10. 4.1 and 2304.9.1, or connections of equivalent capacities shall be provided. Where ceiling joists or rafter ties are not provided at the top of the rafter support walls, the ridge formed by these rafters shall also be supported by a girder conforming to Section 2308.4.

Rafter ties shall be spaced not more than 4 feet (1219 mm) o.c. Rafter tie connections shall be based on the equivalent rafter spacing in Table 2308.10. 4.1. Where rafter ties are spaced at 32 inches (813 mm) o.c., the number of 16d common nails shall be two times the number specified for rafters spaced 16 inches (406 mm) o.c., with a minimum of four 16d common nails where no snow loads are indicated. Where rafter ties are spaced at 48 inches (1219 mm) o.c., the number of 16d common nails shall be two times the number specified for rafters spaced 24 inches (610 mm) o.c., with a minimum of six 16d common nails where no snow loads are indicated. Rafter/ceiling joist connections and rafter/tie connections shall be of sufficient size and number to prevent splitting from nailing.

TABLE 2308.10.2(1)

CEILING JOIST SPANS FOR COMMON LUMBER SPECIES

(Uninhabitable Attics Without Storage, Live Load = 10 pounds psf, L/[DELTA] =

240)

CEILING JOISTSPACING(inches) SPECIES AND GRADE DEAD LOAD = 5 pounds per square foot
2*4 2 * 6 2* 8 2*10
Maximum ceiling joist spans
(ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.)
12 Douglas Fir-Larch SS 13-2 20-8 Note a Note a
Douglas Fir-Larch #1 12-8 19-11 Note a Note a
Douglas Fir-Larch #2 12-5 19-6 25-8 Note a
Douglas Fir-Larch #3 10-10 15-10 20-1 24-6
Hem-Fir SS 12-5 19-6 25-8 Note a
Hem-Fir #1 12-2 19-1 25-2 Note a
Hem-Fir #2 11-7 18-2 24-0 Note a
Hem-Fir #3 10-10 15-10 20-1 24-6
Southern Pine SS 12-11 20-3 Note a Note a
Southern Pine #1 12-8 19-11 Note a Note a
Southern Pine #2 12-5 19-6 25-8 Note a
  Southern Pine #3 11-6 17-0 21-8 25-7
Spruce-Pine-Fir SS 12-2 19-1 25-2 Note a
Spruce-Pine-Fir #1 11-10 18-8 24-7 Note a
Spruce-Pine-Fir #2 11-10 18-8 24-7 Note a
Spruce-Pine-Fir #3 10-10 15-10 20-1 24-6
16 Douglas Fir-Larch SS 11-11 18-9 24-8 Note a
Douglas Fir-Larch #1 11-6 18-1 23-10 Note a
Douglas Fir-Larch #2 11-3 17-8 23-0 Note a
Douglas Fir-Larch #3 9-5 13-9 17-5 21-3
Hem-Fir SS 11-3 17-8 23-4 Note a
Hem-Fir #1 11-0 17-4 22-10 Note a
Hem-Fir #2 10-6 16-6 21-9 Note a
Hem-Fir #3 9-5 13-9 17-5 21-3
Southern Pine SS 11-9 18-5 24-3 Note a
Southern Pine #1 11-6 18-1 23-1 Note a
Southern Pine #2 11-3 17-8 23-4 Note a
Southern Pine #3 10-0 14-9 18-9 22-2
Spruce-Pine-Fir SS 11-0 17-4 22-10 Note a
Spruce-Pine-Fir #1 10-9 16-11 22-4 Note a
Spruce-Pine-Fir #2 10-9 16-11 22-4 Note a
Spruce-Pine-Fir #3 9-5 13-9 17-5 21-3
19.2 Douglas Fir-Larch SS 11-3 17-8 23-3 Note a
Douglas Fir-Larch #1 10-10 17-0 22-5 Note a
Douglas Fir-Larch #2 10-7 16-7 21-0 25-8
Douglas Fir-Larch #3 8-7 12-6 15-10 19-5
Hem-Fir SS 10-7 16-8 21-11 Note a
Hem-Fir #1 10-4 16-4 21-6 Note a
Hem-Fir #2 9-11 15-7 20-6 25-3
Hem-Fir #3 8-7 12-6 15-10 19-5
Southern Pine SS 11-0 17-4 22-10 Note a
Southern Pine #1 10-10 17-0 22-5 Note a
Southern Pine #2 10-7 16-8 21-11 Note a
Southern Pine #3 9-1 13-6 17-2 20-3
Spruce-Pine-Fir SS 10-4 16-4 21-6 Note a
Spruce-Pine-Fir #1 10-2 15-11 21-0 25-8
Spruce-Pine-Fir #2 10-2 15-11 21-0 25-8
Spruce-Pine-Fir #3 8-7 12-6 15-10 19-5
24 Douglas Fir-Larch SS 10-5 16-4 21-7 Note a
Douglas Fir-Larch #1 10-0 15-9 20-1 24-6
Douglas Fir-Larch #2 9-10 14-10 18-9 22-11
Douglas Fir-Larch #3 7-8 11-2 14-2 17-4
  Hem-Fir SS 9-10 15-6 20-5 Note a
Hem-Fir #1 9-8 15-2 19-7 23-11
Hem-Fir #2 9-2 14-5 18-6 22-7
Hem-Fir #3 7-8 11-2 14-2 17-4
Southern Pine SS 10-3 16-1 21-2 Note a
Southern Pine #1 10-0 15-9 20-10 Note a
Southern Pine #2 9-10 15-6 20-1 23-11
Southern Pine #3 8-2 12-0 15-4 18-1
Spruce-Pine-Fir SS 9-8 15-2 19-11 25-5
Spruce-Pine-Fir #1 9-5 14-9 18-9 22-11
Spruce-Pine-Fir #2 9-5 14-9 18-9 22-11
Spruce-Pine-Fir #3 7-8 11-2 14-2 17-4

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 47.8 N/m2 .

a. Span exceeds 26 feet in length. Check sources for availability of lumber in lengths greater than 20 feet.

TABLE 2308.10.2(2)

CEILING JOIST SPANS FOR COMMON LUMBER SPECIES

(Uninhabitable Attics With Limited Storage, Live Load = 20 pounds per

square foot, L/ [DELTA] = 240)

CEILING JOIST SPACING(inches) SPECIES AND GRADE DEAD LOAD = 10 pounds per square foot
2 * 4 2 * 6 2 * 8 2 *10
Maximum ceiling joist spans
(ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.)
12 Douglas Fir-Larch SS 10-5 16-4 21-7 Note a
Douglas Fir-Larch #1 10-0 15-9 20-1 24-6
Douglas Fir-Larch #2 9-10 14-10 18-9 22-11
Douglas Fir-Larch #3 7-8 11-2 14-2 17-4
Hem-Fir SS 9-10 15-6 20-5 Note a
Hem-Fir #1 9-8 15-2 19-7 23-11
Hem-Fir #2 9-2 14-5 18-6 22-7
Hem-Fir #3 7-8 11-2 14-2 17-4
Southern Pine SS 10-3 16-1 21-2 Note a
Southern Pine #1 10-0 15-9 20-10 Note a
Southern Pine #2 9-10 15-6 20-1 23-11
Southern Pine #3 8-2 12-0 15-4 18-1
Spruce-Pine-Fir SS 9-8 15-2 19-11 25-5
Spruce-Pine-Fir #1 9-5 14-9 18-9 22-11
Spruce-Pine-Fir #2 9-5 14-9 18-9 22-11
Spruce-Pine-Fir #3 7-8 11-2 14-2 17-4
16 Douglas Fir-Larch SS 9-6 14-11 19-7 25-0
Douglas Fir-Larch #1 9-1 13-9 17-5 21-3
  Douglas Fir-Larch #2 8-9 12-10 16-3 19-10
Douglas Fir-Larch #3 6-8 9-8 12-4 15-0
Hem-Fir SS 8-11 14-1 18-6 23-8
Hem-Fir #1 8-9 13-5 16-10 20-8
Hem-Fir #2 8-4 12-8 16-0 19-7
Hem-Fir #3 6-8 9-8 12-4 15-0
Southern Pine SS 9-4 14-7 19-3 24-7
Southern Pine #1 9-1 14-4 18-11 23-1
Southern Pine #2 8-11 13-6 17-5 20-9
Southern Pine #3 7-1 10-5 13-3 15-8
Spruce-Pine-Fir SS 8-9 13-9 18-1 23-1
Spruce-Pine-Fir #1 8-7 12-10 16-3 19-10
Spruce-Pine-Fir #2 8-7 12-10 16-3 19-10
Spruce-Pine-Fir #3 6-8 9-8 12-4 15-0
19.2 Douglas Fir-Larch SS 8-11 14-0 18-5 23-4
Douglas Fir-Larch #1 8-7 12-6 15-10 19-5
Douglas Fir-Larch #2 8-0 11-9 14-10 18-2
Douglas Fir-Larch #3 6-1 8-10 11-3 13-8
Hem-Fir SS 8-5 13-3 17-5 22-3
Hem-Fir #1 8-3 12-3 15-6 18-11
Hem-Fir #2 7-10 11-7 14-8 17-10
Hem-Fir #3 6-1 8-10 11-3 13-8
Southern Pine SS 8-9 13-9 18-1 23-1
Southern Pine #1 8-7 13-6 17-9 21-1
Southern Pine #2 8-5 12-3 15-10 18-11
Southern Pine #3 6-5 9-6 12-1 14-4
Spruce-Pine-Fir SS 8-3 12-11 17-1 21-8
Spruce-Pine-Fir #1 8-0 11-9 14-10 18-2
Spruce-Pine-Fir #2 8-0 11-9 14-10 18-2
Spruce-Pine-Fir #3 6-1 8-10 11-3 13-8
24 Douglas Fir-Larch SS 8-3 13-0 17-1 20-11
Douglas Fir-Larch #1 7-8 11-2 14-2 17-4
Douglas Fir-Larch #2 7-2 10-6 13-3 16-3
Douglas Fir-Larch #3 5-5 7-11 10-0 12-3
Hem-Fir SS 7-10 12-3 16-2 20-6
Hem-Fir #1 7-6 10-11 13-10 16-11
Hem-Fir #2 7-1 10-4 13-1 16-0
Hem-Fir #3 5-5 7-11 10-0 12-3
Southern Pine SS 8-1 12-9 16-10 21-6
Southern Pine #1 8-0 12-6 15-10 18-10
Southern Pine #2 7-8 11-0 14-2 16-11
Southern Pine #3 5-9 8-6 10-10 12-10
  Spruce-Pine-Fir SS 7-8 12-0 15-10 19-5
Spruce-Pine-Fir #1 7-2 10-6 13-3 16-3
Spruce-Pine-Fir #2 7-2 10-6 13-3 16-3
Spruce-Pine-Fir #3 5-5 7-11 10-0 12-3

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 47.8 N/m2 .

a. Span exceeds 26 feet in length. Check sources for availability of lumber in lengths greater than 20 feet.

TABLE 2308.10.3(1)

RAFTER SPANS FOR COMMON LUMBER SPECIES

(Roof Live Load = 20 pounds per square foot, Ceiling Not Attached to

Rafters, L/ [DELTA] = 180)

RAFTERS PACING (inches) SPECIES AND GRADE DEAD LOAD = 10 pounds per square foot DEAD LOAD = 20 pounds per square foot
2 * 4 2 * 6 2 * 8 2 * 10 2 * 2 2 * 4 2 * 6 2 * 8 2 * 10 2 * 12
Maximum rafter spans
(ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.)
12 Douglas Fir-Larch SS 11-6 18-0 23-9 Note a Note a 11-6 18-0 23-5 Note a Note a
Douglas Fir-Larch #1 11-1 17-4 22-5 Note a Note a 10-6 15-4 19-5 23-9 Note a
Douglas Fir-Larch #2 10-10 16-7 21-0 25-8 Note a 9-10 14-4 18-2 22-3 25-9
Douglas Fir-Larch #3 8-7 12-6 15-10 19-5 22-6 7-5 10-10 13-9 16-9 19-6
Hem-Fir SS 10-10 17-0 22-5 Note a Note a 10-10 17-0 22-5 Note a Note a
Hem-Fir #1 10-7 16-8 21-10 Note a Note a 10-3 14-11 18-11 23-2 Note a
Hem-Fir #2 10-1 15-11 20-8 25-3 Note a 9-8 14-2 17-11 21-11 25-5
Hem-Fir #3 8-7 12-6 15-10 19-5 22-6 7-5 10-10 13-9 16-9 19-6
Southern Pine SS 11-3 17-8 23-4 Note a Note a 11-3 17-8 23-4 Note a Note a
Southern Pine #1 11-1 17-4 22-11 Note a Note a 11-1 17-3 21-9 25-10 Note a
Southern Pine #2 10-10 17-0 22-5 Note a Note a 10-6 15-1 19-5 23-2 Note a
Southern Pine #3 9-1 13-6 17-2 20-3 24-1 7-11 11-8 14-10 17-6 20-11
Spruce-Pine-Fir SS 10-7 16-8 21-11 Note a Note a 10-7 16-8 21-9 Note a Note a
Spruce-Pine-Fir #1 10-4 16-3 21-0 25-8 Note a 9-10 14-4 18-2 22-322-3 25-9
Spruce-Pine-Fir #2 10-4 16-3 21-0 25-8 Note a 9-10 14-4 18-2 22-3 25-9
Spruce-Pine-Fir #3 8-7 12-6 15-10 19-5 22-6 7-5 10-10 13-9 16-9 19-6
16 Douglas Fir-Larch SS 10-5 16-4 21-7 Note a Note a 10-5 16-0 20-3 24-9 Note a
Douglas Fir-Larch #1 10-0 15-4 19-5 23-9 Note a 9-1 13-3 16-10 20-7 23-10
Douglas Fir-Larch #2 9-10 14-4 18-2 22-3 25-9 8-6 12-5 15-9 19-3 22-4
Douglas Fir-Larch #3 7-5 10-10 13-9 16-9 19-6 6-5 9-5 11-11 14-6 16-10
Hem-Fir SS 9-10 15-6 20-5 Note a Note a 9-10 15-6 19-11 24-4 Note a
Hem-Fir #1 9-8 14-11 18-11 23-2 Note a 8-10 12-11 16-5 20-0 23-3
Hem-Fir #2 9-2 14-2 17-11 21-11 25-5 8-5 12-3 15-6 18-11 22-0
Hem-Fir #3 7-5 10-10 13-9 16-9 19-6 6-5 9-5 11-11 14-6 16-10
Southern Pine SS 10-3 16-1 21-2 Note a Note a 10-3 16-1 21-2 Note a Note a
Southern Pine #1 10-0 15-9 20-10 25-10 Note a 10-0 15-0 18-10 22-4 Note a
  Southern Pine #2 9-10 15-1 19-5 23-2 Note a 9-1 13-0 16-10 20-1 23-7
Southern Pine #3 7-11 11-8 14-10 17-6 20-11 6-10 10-1 12-10 15-2 18-1
Spruce-Pine-Fir SS 9-8 15-2 19-11 25-5 Note a 9-8 14-10 18-10 23-0 Note a
Spruce-Pine-Fir #1 9-5 14-4 18-2 22-3 25-9 8-6 12-5 15-9 19-3 22-4
Spruce-Pine-Fir #2 9-5 14-4 18-2 22-3 25-9 8-6 12-5 15-9 19-3 22-4
Spruce-Pine-Fir #3 7-5 10-10 13-9 16-9 19-6 6-5 9-5 11-11 14-6 16-10
19.2 Douglas Fir-Larch SS 9-10 15-5 20-4 25-11 Note a 9-10 14-7 18-6 22-7 Note a
Douglas Fir-Larch #1 9-5 14-0 17-9 21-8 25-2 8-4 12-2 15-4 18-9 21-9
Douglas Fir-Larch #2 8-11 13-1 16-7 20-3 23-6 7-9 11-4 14-4 17-7 20-4
Douglas Fir-Larch #3 6-9 9-11 12-7 15-4 17-9 5-10 8-7 10-10 13-3 15-5
Hem-Fir SS 9-3 14-7 19-2 24-6 Note a 9-3 14-4 18-2 22-3 25-9
Hem-Fir #1 9-1 13-8 17-4 21-1 24-6 8-1 11-10 15-0 18-4 21-3
Hem-Fir #2 8-8 12-11 16-4 20-0 23-2 7-8 11-2 14-2 17-4 20-1
Hem-Fir #3 6-9 9-11 12-7 15-4 17-9 5-10 8-7 10-10 13-3 15-5
Southern Pine SS 9-8 15-2 19-11 25-5 Note a 9-8 15-2 19-11 25-5 Note a
Southern Pine #1 9-5 14-10 19-7 23-7 Note a 9-3 13-8 17-2 20-5 24-4
Southern Pine #2 9-3 13-9 17-9 21-2 24-10 8-4 11-11 15-4 18-4 21-6
Southern Pine #3 7-3 10-8 13-7 16-0 19-1 6-3 9-3 11-9 13-10 16-6
Spruce-Pine-Fir SS 9-1 14-3 18-9 23-11 Note a 9-1 13-7 17-2 21-0 24-4
Spruce-Pine-Fir #1 8-10 13-1 16-7 20-3 23-6 7-9 11-4 14-4 17-7 20-4
Spruce-Pine-Fir #2 8-10 13-1 16-7 20-3 23-6 7-9 11-4 14-4 17-7 20-4
Spruce-Pine-Fir #3 6-9 9-11 12-7 15-4 17-9 5-10 8-7 10-10 13-3 15-5
24 Douglas Fir-Larch SS 9-1 14-4 18-10 23-4 Note a 8-11 13-1 16-7 20-3 23-5
Douglas Fir-Larch #1 8-7 12-6 15-10 19-5 22-6 7-5 10-10 13-9 16-9 19-6
Douglas Fir-Larch #2 8-0 11-9 14-10 18-2 21-0 6-11 10-2 12-10 15-8 18-3
Douglas Fir-Larch #3 6-1 8-10 11-3 13-8 15-11 5-3 7-8 9-9 11-10 13-9
Hem-Fir SS 8-7 13-6 17-10 22-9 Note a 8-7 12-10 16-3 19-10 23-0
Hem-Fir #1 8-4 12-3 15-6 18-11 21-11 7-3 10-7 13-5 16-4 19-0
Hem-Fir #2 7-11 11-7 14-8 17-10 20-9 6-10 10-0 12-8 15-6 17-11
Hem-Fir #3 6-1 8-10 11-3 13-8 15-11 5-3 7-8 9-9 11-10 13-9
Southern Pine SS 8-11 14-1 18-6 23-8 Note a 8-11 14-1 18-6 22-11 Note a
Southern Pine #1 8-9 13-9 17-9 21-1 25-2 8-3 12-3 15-4 18-3 21-9
Southern Pine #2 8-7 12-3 15-10 18-11 22-2 7-5 10-8 13-9 16-5 19-3
Southern Pine #3 6-5 9-6 12-1 14-4 17-1 5-7 8-3 10-6 12-5 14-9
Spruce-Pine-Fir SS 8-5 13-3 17-5 21-8 25-2 8-4 12-2 15-4 18-9 21-9
Spruce-Pine-Fir #1 8-0 11-9 14-10 18-2 21-0 6-11 10-2 12-10 15-8 18-3
Spruce-Pine-Fir #2 8-0 11-9 14-10 18-2 21-0 6-11 10-2 12-10 15-8 18-3
Spruce-Pine-Fir #3 6-1 8-10 11-3 13-8 15-11 5-3 7-8 9-9 11-10 13-9

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 47.9 N/m2 .

a. Span exceeds 26 feet in length. Check sources for availability of lumber in lengths greater than 20 feet.

TABLE 2308.10.3(2)

RAFTER SPANS FOR COMMON LUMBER SPECIES

(Roof Live Load = 20 pounds per square foot, Ceiling Not Attached to

Rafters, L/ [DELTA]= 240)

RAFTERS PACING (inches) SPECIES AND GRADE DEAD LOAD = 10 pounds per square foot DEAD LOAD = 20 pounds per square foot
2 * 4 2 * 6 2 * 8 2 * 10 2 * 12 2 * 4 2 * 6 2 * 8 2 * 10 2 * 12
Maximum rafter spans
(ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.)
12 Douglas Fir-Larch SS 10-5 16-4 21-7 Note a Note a 10-5 16-4 21-7 Note a Note a
Douglas Fir-Larch #1 10-0 15-9 20-10 Note a Note a 10-0 15-4 19-5 23-9 Note a
Douglas Fir-Larch #2 9-10 15-6 20-5 25-8 Note a 9-10 14-4 18-2 22-3 25-9
Douglas Fir-Larch #3 8-7 12-6 15-10 19-5 22-6 7-5 10-10 13-9 16-9 19-6
Hem-Fir SS 9-10 15-6 20-5 Note a Note a 9-10 15-6 20-5 Note a Note a
Hem-Fir #1 9-8 15-2 19-11 25-5 Note a 9-8 14-11 18-11 23-2 Note a
Hem-Fir #2 9-2 14-5 19-0 24-3 Note a 9-2 14-2 17-11 21-11 25-5
Hem-Fir #3 8-7 12-6 15-10 19-5 22-6 7-5 10-10 13-9 16-9 19-6
Southern Pine SS 10-3 16-1 21-2 Note a Note a 10-3 16-1 21-2 Note a Note a
Southern Pine #1 10-0 15-9 20-10 Note a Note a 10-0 15-9 20-10 25-10 Note a
Southern Pine #2 9-10 15-6 20-5 Note a Note a 9-10 15-1 19-5 23-2 Note a
Southern Pine #3 9-1 13-6 17-2 20-3 24-1 7-11 11-8 14-10 17-6 20-11
Spruce-Pine-Fir SS 9-8 15-2 19-11 25-5 Note a 9-8 15-2 19-11 25-5 Note a
Spruce-Pine-Fir #1 9-5 14-9 19-6 24-10 Note a 9-5 14-4 18-2 22-3 25-9
Spruce-Pine-Fir #2 9-5 14-9 19-6 24-10 Note a 9-5 14-4 18-2 22-3 25-9
Spruce-Pine-Fir #3 8-7 12-6 15-10 19-5 22-6 7-5 10-10 13-9 16-9 19-6
16 Douglas Fir-Larch SS 9-6 14-11 19-7 25-0 Note a 9-6 14-11 19-7 24-9 Note a
Douglas Fir-Larch #1 9-1 14-4 18-11 23-9 Note a 9-1 13-3 16-10 20-7 23-10
Douglas Fir-Larch #2 8-11 14-1 18-2 22-3 25-9 8-6 12-5 15-9 19-3 22-4
Douglas Fir-Larch #3 7-5 10-10 13-9 16-9 19-6 6-5 9-5 11-11 14-6 16-10
Hem-Fir SS 8-11 14-1 18-6 23-8 Note a 8-11 14-1 18-6 23-8 Note a
Hem-Fir #1 8-9 13-9 18-1 23-1 Note a 8-9 12-11 16-5 20-0 23-3
Hem-Fir #2 8-4 13-1 17-3 21-11 25-5 8-4 12-3 15-6 18-11 22-0
Hem-Fir #3 7-5 10-10 13-9 16-9 19-6 6-5 9-5 11-11 14-6 16-10
Southern Pine SS 9-4 14-7 19-3 24-7 Note a 9-4 14-7 19-3 24-7 Note a
Southern Pine #1 9-1 14-4 18-11 24-1 Note a 9-1 14-4 18-10 22-4 Note a
Southern Pine #2 8-11 14-1 18-6 23-2 Note a 8-11 13-0 16-10 20-1 23-7
Southern Pine #3 7-11 11-8 14-10 17-6 20-11 6-10 10-1 12-10 15-2 18-1
Spruce-Pine-Fir SS 8-9 13-9 18-1 23-1 Note a 8-9 13-9 18-1 23-0 Note a
Spruce-Pine-Fir #1 8-7 13-5 17-9 22-3 25-9 8-6 12-5 15-9 19-3 22-4
Spruce-Pine-Fir #2 8-7 13-5 17-9 22-3 25-9 8-6 12-5 15-9 19-3 22-4
Spruce-Pine-Fir #3 7-5 10-10 13-9 16-9 19-6 6-5 9-5 11-11 14-6 16-10
19.2 Douglas Fir-Larch SS 8-11 14-0 18-5 23-7 Note a 8-11 14-0 18-5 22-7 Note a
  Douglas Fir-Larch #1 8-7 13-6 17-9 21-8 25-2 8-4 12-2 15-4 18-9 21-9
Douglas Fir-Larch #2 8-5 13-1 16-7 20-3 23-6 7-9 11-4 14-4 17-7 20-4
Douglas Fir-Larch #3 6-9 9-11 12-7 15-4 17-9 5-10 8-7 10-10 13-3 15-5
Hem-Fir SS 8-5 13-3 17-5 22-3 Note a 8-5 13-3 17-5 22-3 25-9
Hem-Fir #1 8-3 12-11 17-1 21-1 24-6 8-1 11-10 15-0 18-4 21-3
Hem-Fir #2 7-10 12-4 16-3 20-0 23-2 7-8 11-2 14-2 17-4 20-1
Hem-Fir #3 6-9 9-11 12-7 15-4 17-9 5-10 8-7 10-10 13-3 15-5
Southern Pine SS 8-9 13-9 18-1 23-1 Note a 8-9 13-9 18-1 23-1 Note a
Southern Pine #1 8-7 13-6 17-9 22-8 Note a 8-7 13-6 17-2 20-5 24-4
Southern Pine #2 8-5 13-3 17-5 21-2 24-10 8-4 11-11 15-4 18-4 21-6
Southern Pine #3 7-3 10-8 13-7 16-0 19-1 6-3 9-3 11-9 13-10 16-6
Spruce-Pine-Fir SS 8-3 12-11 17-1 21-9 Note a 8-3 12-11 17-1 21-0 24-4
Spruce-Pine-Fir #1 8-1 12-8 16-7 20-3 23-6 7-9 11-4 14-4 17-7 20-4
Spruce-Pine-Fir #2 8-1 12-8 16-7 20-3 23-6 7-9 11-4 14-4 17-7 20-4
Spruce-Pine-Fir #3 6-9 9-11 12-7 15-4 17-9 5-10 8-7 10-10 13-3 15-5
24 Douglas Fir-Larch SS 8-3 13-0 17-2 21-10 Note a 8-3 13-0 16-7 20-3 23-5
Douglas Fir-Larch #1 8-0 12-6 15-10 19-5 22-6 7-5 10-10 13-9 16-9 19-6
Douglas Fir-Larch #2 7-10 11-9 14-10 18-2 21-0 6-11 10-2 12-10 15-8 18-3
Douglas Fir-Larch #3 6-1 8-10 11-3 13-8 15-11 5-3 7-8 9-9 11-10 13-9
Hem-Fir SS 7-10 12-3 16-2 20-8 25-1 7-10 12-3 16-2 19-10 23-0
Hem-Fir #1 7-8 12-0 15-6 18-11 21-11 7-3 10-7 13-5 16-4 19-0
Hem-Fir #2 7-3 11-5 14-8 17-10 20-9 6-10 10-0 12-8 15-6 17-11
Hem-Fir #3 6-1 8-10 11-3 13-8 15-11 5-3 7-8 9-9 11-10 13-9
Southern Pine SS 8-1 12-9 16-10 21-6 Note a 8-1 12-9 16-10 21-6 Note a
Southern Pine #1 8-0 12-6 16-6 21-1 25-2 8-0 12-3 15-4 18-3 21-9
Southern Pine #2 7-10 12-3 15-10 18-11 22-2 7-5 10-8 13-9 16-5 19-3
Southern Pine #3 6-5 9-6 12-1 14-4 17-1 5-7 8-3 10-6 12-5 14-9
Spruce-Pine-Fir SS 7-8 12-0 15-10 20-2 24-7 7-8 12-0 15-4 18-9 21-9
Spruce-Pine-Fir #1 7-6 11-9 14-10 18-2 21-0 6-11 10-2 12-10 15-8 18-3
Spruce-Pine-Fir #2 7-6 11-9 14-10 18-2 21-0 6-11 10-2 12-10 15-8 18-3
Spruce-Pine-Fir #3 6-1 8-10 11-3 13-8 15-11 5-3 7-8 9-9 11-10 13-9

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 47.9 N/m2 .

a. Span exceeds 26 feet in length. Check sources for availability of lumber in lengths greater than 20 feet.

TABLE 2308.10.3(3)

RAFTER SPANS FOR COMMON LUMBER SPECIES

(Ground Snow Load = 30 pounds per square foot, Ceiling Not Attached to

Rafters, L/ [DELTA] = 180)

RAFTERSPACING(inches) SPECIES AND GRADE DEAD LOAD = 10 pounds per square foot DEAD LOAD = 20 pounds per square foot
2 * 4 2 *6 2 * 8 2 *10 2 *12 2 *4 2 * 6 2 *8 2 * 10 2 * 12
Maximum rafter spans
      (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.)
12 Douglas Fir-Larch SS 10-0 15-9 20-9 Note a Note a 10-0 15-9 20-1 24-6 Note a
Douglas Fir-Larch #1 9-8 14-9 18-8 22-9 Note a 9-0 13-2 16-8 20-4 23-7
Douglas Fir-Larch #2 9-5 13-9 17-5 21-4 24-8 8-5 12-4 15-7 19-1 22-1
Douglas Fir-Larch #3 7-1 10-5 13-2 16-1 18-8 6-4 9-4 11-9 14-5 16-8
Hem-Fir SS 9-6 14-10 19-7 25-0 Note a 9-6 14-10 19-7 24-1 Note a
Hem-Fir #1 9-3 14-4 18-2 22-2 25-9 8-9 12-10 16-3 19-10 23-0
Hem-Fir #2 8-10 13-7 17-2 21-0 24-4 8-4 12-2 15-4 18-9 21-9
Hem-Fir #3 7-1 10-5 13-2 16-1 18-8 6-4 9-4 11-9 14-5 16-8
Southern Pine SS 9-10 15-6 20-5 Note a Note a 9-10 15-6 20-5 Note a Note a
Southern Pine #1 9-8 15-2 20-0 24-9 Note a 9-8 14-10 18-8 22-2 Note a
Southern Pine #2 9-6 14-5 18-8 22-3 Note a 9-0 12-11 16-8 19-11 23-4
Southern Pine #3 7-7 11-2 14-3 16-10 20-0 6-9 10-0 12-9 15-1 17-11
Spruce-Pine-Fir SS 9-3 14-7 19-2 24-6 Note a 9-3 14-7 18-8 22-9 Note a
Spruce-Pine-Fir #1 9-1 13-9 17-5 21-4 24-8 8-5 12-4 15-7 19-1 22-1
Spruce-Pine-Fir #2 9-1 13-9 17-5 21-4 24-8 8-5 12-4 15-7 19-1 22-1
Spruce-Pine-Fir #3 7-1 10-5 13-2 16-1 18-8 6-4 9-4 11-9 14-5 16-8
16 Douglas Fir-Larch SS 9-1 14-4 18-10 23-9 Note a 9-1 13-9 17-5 21-3 24-8
Douglas Fir-Larch #1 8-9 12-9 16-2 19-9 22-10 7-10 11-5 14-5 17-8 20-5
Douglas Fir-Larch #2 8-2 11-11 15-1 18-5 21-5 7-3 10-8 13-6 16-6 19-2
Douglas Fir-Larch #3 6-2 9-0 11-5 13-11 16-2 5-6 8-1 10-3 12-6 14-6
Hem-Fir SS 8-7 13-6 17-10 22-9 Note a 8-7 13-6 17-1 20-10 24-2
Hem-Fir #1 8-5 12-5 15-9 19-3 22-3 7-7 11-1 14-1 17-2 19-11
Hem-Fir #2 8-0 11-9 14-11 18-2 21-1 7-2 10-6 13-4 16-3 18-10
Hem-Fir #3 6-2 9-0 11-5 13-11 16-2 5-6 8-1 10-3 12-6 14-6
Southern Pine SS 8-11 14-1 18-6 23-8 Note a 8-11 14-1 18-6 23-8 Note a
Southern Pine #1 8-9 13-9 18-1 21-5 25-7 8-8 12-10 16-2 19-2 22-10
Southern Pine #2 8-7 12-6 16-2 19-3 22-7 7-10 11-2 14-5 17-3 20-2
Southern Pine #3 6-7 9-8 12-4 14-7 17-4 5-10 8-8 11-0 13-0 15-6
Spruce-Pine-Fir SS 8-5 13-3 17-5 22-1 25-7 8-5 12-9 16-2 19-9 22-10
Spruce-Pine-Fir #1 8-2 11-11 15-1 18-5 21-5 7-3 10-8 13-6 16-6 19-2
Spruce-Pine-Fir #2 8-2 11-11 15-1 18-5 21-5 7-3 10-8 13-6 16-6 19-2
Spruce-Pine-Fir #3 6-2 9-0 11-5 13-11 16-2 5-6 8-1 10-3 12-6 14-6
19.2 Douglas Fir-Larch SS 8-7 13-6 17-9 21-8 25-2 8-7 12-6 15-10 19-5 22-6
Douglas Fir-Larch #1 7-11 11-8 14-9 18-0 20-11 7-1 10-5 13-2 16-1 18-8
Douglas Fir-Larch #2 7-5 10-11 13-9 16-10 19-6 6-8 9-9 12-4 15-1 17-6
Douglas Fir-Larch #3 5-7 8-3 10-5 12-9 14-9 5-0 7-4 9-4 11-5 13-2
Hem-Fir SS 8-1 12-9 16-9 21-4 24-8 8-1 12-4 15-7 19-1 22-1
Hem-Fir #1 7-9 11-4 14-4 17-7 20-4 6-11 10-2 12-10 15-8 18-2
Hem-Fir #2 7-4 10-9 13-7 16-7 19-3 6-7 9-7 12-2 14-10 17-3
Hem-Fir #3 5-7 8-3 10-5 12-9 14-9 5-0 7-4 9-4 11-5 13-2
Southern Pine SS 8-5 13-3 17-5 22-3 Note a 8-5 13-3 17-5 22-0 25-9
  Southern Pine #1 8-3 13-0 16-6 19-7 23-4 7-11 11-9 14-9 17-6 20-11
Southern Pine #2 7-11 11-5 14-9 17-7 20-7 7-1 10-2 13-2 15-9 18-5
Southern Pine #3 6-0 8-10 11-3 13-4 15-10 5-4 7-11 10-1 11-11 14-2
Spruce-Pine-Fir SS 7-11 12-5 16-5 20-2 23-4 7-11 11-8 14-9 18-0 20-11
Spruce-Pine-Fir #1 7-5 10-11 13-9 16-10 19-6 6-8 9-9 12-4 15-1 17-6
Spruce-Pine-Fir #2 7-5 10-11 13-9 16-10 19-6 6-8 9-9 12-4 15-1 17-6
Spruce-Pine-Fir #3 5-7 8-3 10-5 12-9 14-9 5-0 7-4 9-4 11-5 13-2
24 Douglas Fir-Larch SS 7-11 12-6 15-10 19-5 22-6 7-8 11-3 14-2 17-4 20-1
Douglas Fir-Larch #1 7-1 10-5 13-2 16-1 18-8 6-4 9-4 11-9 14-5 16-8
Douglas Fir-Larch #2 6-8 9-9 12-4 15-1 17-6 5-11 8-8 11-0 13-6 15-7
Douglas Fir-Larch #3 5-0 7-4 9-4 11-5 13-2 4-6 6-7 8-4 10-2 11-10
Hem-Fir SS 7-6 11-10 15-7 19-1 22-1 7-6 11-0 13-11 17-0 19-9
Hem-Fir #1 6-11 10-2 12-10 15-8 18-2 6-2 9-1 11-6 14-0 16-3
Hem-Fir #2 6-7 9-7 12-2 14-10 17-3 5-10 8-7 10-10 13-3 15-5
Hem-Fir #3 5-0 7-4 9-4 11-5 13-2 4-6 6-7 8-4 10-2 11-10
Southern Pine SS 7-10 12-3 16-2 20-8 25-1 7-10 12-3 16-2 19-8 23-0
Southern Pine #1 7-8 11-9 14-9 17-6 20-11 7-1 10-6 13-2 15-8 18-8
Southern Pine #2 7-1 10-2 13-2 15-9 18-5 6-4 9-2 11-9 14-1 16-6
Southern Pine #3 5-4 7-11 10-1 11-11 14-2 4-9 7-1 9-0 10-8 12-8
Spruce-Pine-Fir SS 7-4 11-7 14-9 18-0 20-11 7-1 10-5 13-2 16-1 18-8
Spruce-Pine-Fir #1 6-8 9-9 12-4 15-1 17-6 5-11 8-8 11-0 13-6 15-7
Spruce-Pine-Fir #2 6-8 9-9 12-4 15-1 17-6 5-11 8-8 11-0 13-6 15-7
Spruce-Pine-Fir #3 5-0 7-4 9-4 11-5 13-2 4-6 6-7 8-4 10-2 11-10

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 47.9 N/m2 .

a. Span exceeds 26 feet in length. Check sources for availability of lumber in lengths greater than 20 feet.

TABLE 2308.10.3(4)

RAFTER SPANS FOR COMMON LUMBER SPECIES

(Ground Snow Load = 50 pounds per square foot, Ceiling Not Attached to

Rafters, L/ [DELTA] = 180)

RAFTERSPACING(inches) SPECIES AND GRADE DEAD LOAD = 10 pounds per square foot DEAD LOAD = 20 pounds per square foot
2 * 4 2 *6 2 * 8 2 *10 2 *12 2 *4 2 * 6 2 *8 2 * 10 2 * 12
Maximum rafter spans
(ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.)
12 Douglas Fir-Larch SS 8-5 13-3 17-6 22-4 26-0 8-5 13-3 17-0 20-9 24-10
Douglas Fir-Larch #1 8-2 12-0 15-3 18-7 21-7 7-7 11-2 14-1 17-3 20-0
Douglas Fir-Larch #2 7-8 11-3 14-3 17-5 20-2 7-1 10-5 13-2 16-1 18-8
Douglas Fir-Larch #3 5-10 8-6 10-9 13-2 15-3 5-5 7-10 10-0 12-2 14-1
Hem-Fir SS 8-0 12-6 16-6 21-1 25-6 8-0 12-6 16-6 20-4 23-7
Hem-Fir #1 7-10 11-9 14-10 18-1 21-0 7-5 10-10 13-9 16-9 19-5
Hem-Fir #2 7-5 11-1 14-0 17-2 19-11 7-0 10-3 13-0 15-10 18-5
  Hem-Fir #3 5-10 8-6 10-9 13-2 15-3 5-5 7-10 10-0 12-2 14-1
Southern Pine SS 8-4 13-0 17-2 21-11 Note a 8-4 13-0 17-2 21-11 Note a
Southern Pine #1 8-2 12-10 16-10 20-3 24-1 8-2 12-6 15-9 18-9 22-4
Southern Pine #2 8-0 11-9 15-3 18-2 21-3 7-7 10-11 14-1 16-10 19-9
Southern Pine #3 6-2 9-2 11-8 13-9 16-4 5-9 8-5 10-9 12-9 15-2
Spruce-Pine-Fir SS 7-10 12-3 16-2 20-8 24-1 7-10 12-3 15-9 19-3 22-4
Spruce-Pine-Fir #1 7-8 11-3 14-3 17-5 20-2 7-1 10-5 13-2 16-1 18-8
Spruce-Pine-Fir #2 7-8 11-3 14-3 17-5 20-2 7-1 10-5 13-2 16-1 18-8
Spruce-Pine-Fir #3 5-10 8-6 10-9 13-2 15-3 5-5 7-10 10-0 12-2 14-1
16 Douglas Fir-Larch SS 7-8 12-1 15-10 19-5 22-6 7-8 11-7 14-8 17-11 20-10
Douglas Fir-Larch #1 7-1 10-5 13-2 16-1 18-8 6-7 9-8 12-2 14-11 17-3
Douglas Fir-Larch #2 6-8 9-9 12-4 15-1 17-6 6-2 9-0 11-5 13-11 16-2
Douglas Fir-Larch #3 5-0 7-4 9-4 11-5 13-2 4-8 6-10 8-8 10-6 12-3
Hem-Fir SS 7-3 11-5 15-0 19-1 22-1 7-3 11-5 14-5 17-8 20-5
Hem-Fir #1 6-11 10-2 12-10 15-8 18-2 6-5 9-5 11-11 14-6 16-10
Hem-Fir #2 6-7 9-7 12-2 14-10 17-3 6-1 8-11 11-3 13-9 15-11
Hem-Fir #3 5-0 7-4 9-4 11-5 13-2 4-8 6-10 8-8 10-6 12-3
Southern Pine SS 7-6 11-10 15-7 19-11 24-3 7-6 11-10 15-7 19-11 23-10
Southern Pine #1 7-5 11-7 14-9 17-6 20-11 7-4 10-10 13-8 16-2 19-4
Southern Pine #2 7-1 10-2 13-2 15-9 18-5 6-7 9-5 12-2 14-7 17-1
Southern Pine #3 5-4 7-11 10-1 11-11 14-2 4-11 7-4 9-4 11-0 13-1
Spruce-Pine-Fir SS 7-1 11-2 14-8 18-0 20-11 7-1 10-9 13-8 16-8 19-4
Spruce-Pine-Fir #1 6-8 9-9 12-4 15-1 17-6 6-2 9-0 11-5 13-11 16-2
Spruce-Pine-Fir #2 6-8 9-9 12-4 15-1 17-6 6-2 9-0 11-5 13-11 16-2
Spruce-Pine-Fir #3 5-0 7-4 9-4 11-5 13-2 4-8 6-10 8-8 10-6 12-3
19.2 Douglas Fir-Larch SS 7-3 11-4 14-6 17-8 20-6 7-3 10-7 13-5 16-5 19-0
Douglas Fir-Larch #1 6-6 9-6 12-0 14-8 17-1 6-0 8-10 11-2 13-7 15-9
Douglas Fir-Larch #2 6-1 8-11 11-3 13-9 15-11 5-7 8-3 10-5 12-9 14-9
Douglas Fir-Larch #3 4-7 6-9 8-6 10-5 12-1 4-3 6-3 7-11 9-7 11-2
Hem-Fir SS 6-10 10-9 14-2 17-5 20-2 6-10 10-5 13-2 16-1 18-8
Hem-Fir #1 6-4 9-3 11-9 14-4 16-7 5-10 8-7 10-10 13-3 15-5
Hem-Fir #2 6-0 8-9 11-1 13-7 15-9 5-7 8-1 10-3 12-7 14-7
Hem-Fir #3 4-7 6-9 8-6 10-5 12-1 4-3 6-3 7-11 9-7 11-2
Southern Pine SS 7-1 11-2 14-8 18-9 22-10 7-1 11-2 14-8 18-7 21-9
Southern Pine #1 7-0 10-8 13-5 16-0 19-1 6-8 9-11 12-5 14-10 17-8
Southern Pine #2 6-6 9-4 12-0 14-4 16-10 6-0 8-8 11-2 13-4 15-7
Southern Pine #3 4-11 7-3 9-2 10-10 12-11 4-6 6-8 8-6 10-1 12-0
Spruce-Pine-Fir SS 6-8 10-6 13-5 16-5 19-1 6-8 9-10 12-5 15-3 17-8
Spruce-Pine-Fir #1 6-1 8-11 11-3 13-9 15-11 5-7 8-3 10-5 12-9 14-9
Spruce-Pine-Fir #2 6-1 8-11 11-3 13-9 15-11 5-7 8-3 10-5 12-9 14-9
Spruce-Pine-Fir #3 4-7 6-9 8-6 10-5 12-1 4-3 6-3 7-11 9-7 11-2
24 Douglas Fir-Larch SS 6-8 10-3 13-0 15-10 18-4 6-6 9-6 12-0 14-8 17-0
  Douglas Fir-Larch #1 5-10 8-6 10-9 13-2 15-3 5-5 7-10 10-0 12-2 14-1
Douglas Fir-Larch #2 5-5 7-11 10-1 12-4 14-3 5-0 7-4 9-4 11-5 13-2
Douglas Fir-Larch #3 4-1 6-0 7-7 9-4 10-9 3-10 5-7 7-1 8-7 10-0
Hem-Fir SS 6-4 9-11 12-9 15-7 18-0 6-4 9-4 11-9 14-5 16-8
Hem-Fir #1 5-8 8-3 10-6 12-10 14-10 5-3 7-8 9-9 11-10 13-9
Hem-Fir #2 5-4 7-10 9-11 12-1 14-1 4-11 7-3 9-2 11-3 13-0
Hem-Fir #3 4-1 6-0 7-7 9-4 10-9 3-10 5-7 7-1 8-7 10-0
Southern Pine SS 6-7 10-4 13-8 17-5 21-0 6-7 10-4 13-8 16-7 19-5
Southern Pine #1 6-5 9-7 12-0 14-4 17-1 6-0 8-10 11-2 13-3 15-9
Southern Pine #2 5-10 8-4 10-9 12-10 15-1 5-5 7-9 10-0 11-11 13-11
Southern Pine #3 4-4 6-5 8-3 9-9 11-7 4-1 6-0 7-7 9-0 10-8
Spruce-Pine-Fir SS 6-2 9-6 12-0 14-8 17-1 6-0 8-10 11-2 13-7 15-9
Spruce-Pine-Fir #1 5-5 7-11 10-1 12-4 14-3 5-0 7-4 9-4 11-5 13-2
Spruce-Pine-Fir #2 5-5 7-11 10-1 12-4 14-3 5-0 7-4 9-4 11-5 13-2
Spruce-Pine-Fir #3 4-1 6-0 7-7 9-4 10-9 3-10 5-7 7-1 8-7 10-0

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 47.9 N/m2 .

a. Span exceeds 26 feet in length. Check sources for availability of lumber in lengths greater than 20 feet.

TABLE 2308.10.3(5)

RAFTER SPANS FOR COMMON LUMBER SPECIES

(Ground Snow Load = 30 pounds per square foot, Ceiling Attached to

Rafters, L/ [DELTA] = 240)

RAFTERSPACING(inches) SPECIES AND GRADE DEAD LOAD = 10 pounds per square foot DEAD LOAD = 20 pounds per square foot
2 * 4 2 *6 2 * 8 2 *10 2 *12 2 *4 2 * 6 2 *8 2 * 10 2 * 12
Maximum rafter spans
(ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.)
12 Douglas Fir-Larch SS 9-1 14-4 18-10 24-1 Note a 9-1 14-4 18-10 24-1 Note a
Douglas Fir-Larch #1 8-9 13-9 18-2 22-9 Note a 8-9 13-2 16-8 20-4 23-7
Douglas Fir-Larch #2 8-7 13-6 17-5 21-4 24-8 8-5 12-4 15-7 19-1 22-1
Douglas Fir-Larch #3 7-1 10-5 13-2 16-1 18-8 6-4 9-4 11-9 14-5 16-8
Hem-Fir SS 8-7 13-6 17-10 22-9 Note a 8-7 13-6 17-10 22-9 Note a
Hem-Fir #1 8-5 13-3 17-5 22-2 25-9 8-5 12-10 16-3 19-10 23-0
Hem-Fir #2 8-0 12-7 16-7 21-0 24-4 8-0 12-2 15-4 18-9 21-9
Hem-Fir #3 7-1 10-5 13-2 16-1 18-8 6-4 9-4 11-9 14-5 16-8
Southern Pine SS 8-11 14-1 18-6 23-8 Note a 8-11 14-1 18-6 23-8 Note a
Southern Pine #1 8-9 13-9 18-2 23-2 Note a 8-9 13-9 18-2 22-2 Note a
Southern Pine #2 8-7 13-6 17-10 22-3 Note a 8-7 12-11 16-8 19-11 23-4
Southern Pine #3 7-7 11-2 14-3 16-10 20-0 6-9 10-0 12-9 15-1 17-11
Spruce-Pine-Fir SS 8-5 13-3 17-5 22-3 Note a 8-5 13-3 17-5 22-3 Note a
Spruce-Pine-Fir #1 8-3 12-11 17-0 21-4 24-8 8-3 12-4 15-7 19-1 22-1
Spruce-Pine-Fir #2 8-3 12-11 17-0 21-4 24-8 8-3 12-4 15-7 19-1 22-1
Spruce-Pine-Fir #3 7-1 10-5 13-2 16-1 18-8 6-4 9-4 11-9 14-5 16-8
16 Douglas Fir-Larch SS 8-3 13-0 17-2 21-10 Note a 8-3 13-0 17-2 21-3 24-8
Douglas Fir-Larch #1 8-0 12-6 16-2 19-9 22-10 7-10 11-5 14-5 17-8 20-5
Douglas Fir-Larch #2 7-10 11-11 15-1 18-5 21-5 7-3 10-8 13-6 16-6 19-2
Douglas Fir-Larch #3 6-2 9-0 11-5 13-11 16-2 5-6 8-1 10-3 12-6 14-6
Hem-Fir SS 7-10 12-3 16-2 20-8 25-1 7-10 12-3 16-2 20-8 24-2
Hem-Fir #1 7-8 12-0 15-9 19-3 22-3 7-7 11-1 14-1 17-2 19-11
Hem-Fir #2 7-3 11-5 14-11 18-2 21-1 7-2 10-6 13-4 16-3 18-10
Hem-Fir #3 6-2 9-0 11-5 13-11 16-2 5-6 8-1 10-3 12-6 14-6
Southern Pine SS 8-1 12-9 16-10 21-6 Note a 8-1 12-9 16-10 21-6 Note a
Southern Pine #1 8-0 12-6 16-6 21-1 25-7 8-0 12-6 16-2 19-2 22-10
Southern Pine #2 7-10 12-3 16-2 19-3 22-7 7-10 11-2 14-5 17-3 20-2
Southern Pine #3 6-7 9-8 12-4 14-7 17-4 5-10 8-8 11-0 13-0 15-6
Spruce-Pine-Fir SS 7-8 12-0 15-10 20-2 24-7 7-8 12-0 15-10 19-9 22-10
Spruce-Pine-Fir #1 7-6 11-9 15-1 18-5 21-5 7-3 10-8 13-6 16-6 19-2
Spruce-Pine-Fi #2 7-6 11-9 15-1 18-5 21-5 7-3 10-8 13-6 16-6 19-2
Spruce-Pine-Fi #3 6-2 9-0 11-5 13-11 16-2 5-6 8-1 10-3 12-6 14-6
19.2 Douglas Fir-Larch SS 7-9 12-3 16-1 20-7 25-0 7-9 12-3 15-10 19-5 22-6
Douglas Fir-Larch #1 7-6 11-8 14-9 18-0 20-11 7-1 10-5 13-2 16-1 18-8
Douglas Fir-Larch #2 7-4 10-11 13-9 16-10 19-6 6-8 9-9 12-4 15-1 17-6
Douglas Fir-Larch #3 5-7 8-3 10-5 12-9 14-9 5-0 7-4 9-4 11-5 13-2
Hem-Fir SS 7-4 11-7 15-3 19-5 23-7 7-4 11-7 15-3 19-1 22-1
Hem-Fir #1 7-2 11-4 14-4 17-7 20-4 6-11 10-2 12-10 15-8 18-2
Hem-Fir #2 6-10 10-9 13-7 16-7 19-3 6-7 9-7 12-2 14-10 17-3
Hem-Fir #3 5-7 8-3 10-5 12-9 14-9 5-0 7-4 9-4 11-5 13-2
Southern Pine SS 7-8 12-0 15-10 20-2 24-7 7-8 12-0 15-10 20-2 24-7
Southern Pine #1 7-6 11-9 15-6 19-7 23-4 7-6 11-9 14-9 17-6 20-11
Southern Pine #2 7-4 11-5 14-9 17-7 20-7 7-1 10-2 13-2 15-9 18-5
Southern Pine #3 6-0 8-10 11-3 13-4 15-10 5-4 7-11 10-1 11-11 14-2
Spruce-Pine-Fir SS 7-2 11-4 14-11 19-0 23-1 7-2 11-4 14-9 18-0 20-11
Spruce-Pine-Fir #1 7-0 10-11 13-9 16-10 19-6 6-8 9-9 12-4 15-1 17-6
Spruce-Pine-Fir #2 7-0 10-11 13-9 16-10 19-6 6-8 9-9 12-4 15-1 17-6
Spruce-Pine-Fir #3 5-7 8-3 10-5 12-9 14-9 5-0 7-4 9-4 11-5 13-2
24 Douglas Fir-Larch SS 7-3 11-4 15-0 19-1 22-6 7-3 11-3 14-2 17-4 20-1
Douglas Fir-Larch #1 7-0 10-5 13-2 16-1 18-8 6-4 9-4 11-9 14-5 16-8
Douglas Fir-Larch #2 6-8 9-9 12-4 15-1 17-6 5-11 8-8 11-0 13-6 15-7
Douglas Fir-Larch #3 5-0 7-4 9-4 11-5 13-2 4-6 6-7 8-4 10-2 11-10
Hem-Fir SS 6-10 10-9 14-2 18-0 21-11 6-10 10-9 13-11 17-0 19-9
Hem-Fir #1 6-8 10-2 12-10 15-8 18-2 6-2 9-1 11-6 14-0 16-3
Hem-Fir #2 6-4 9-7 12-2 14-10 17-3 5-10 8-7 10-10 13-3 15-5
Hem-Fir #3 5-0 7-4 9-4 11-5 13-2 4-6 6-7 8-4 10-2 11-10
Southern Pine SS 7-1 11-2 14-8 18-9 22-10 7-1 11-2 14-8 18-9 22-10
  Southern Pine #1 7-0 10-11 14-5 17-6 20-11 7-0 10-6 13-2 15-8 18-8
Southern Pine #2 6-10 10-2 13-2 15-9 18-5 6-4 9-2 11-9 14-1 16-6
Southern Pine #3 5-4 7-11 10-1 11-11 14-2 4-9 7-1 9-0 10-8 12-8
Spruce-Pine-Fir SS 6-8 10-6 13-10 17-8 20-11 6-8 10-5 13-2 16-1 18-8
Spruce-Pine-Fir #1 6-6 9-9 12-4 15-1 17-6 5-11 8-8 11-0 13-6 15-7
Spruce-Pine-Fir #2 6-6 9-9 12-4 15-1 17-6 5-11 8-8 11-0 13-6 15-7
Spruce-Pine-Fir #3 5-0 7-4 9-4 11-5 13-2 4-6 6-7 8-4 10-2 11-10

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 47.9 N/m2 .

a. Span exceeds 26 feet in length. Check sources for availability of lumber in lengths greater than 20 feet.

TABLE 2308.10.3(6)

RAFTER SPANS FOR COMMON LUMBER SPECIES

(Ground Snow Load = 50 pounds per square foot, Ceiling Attached to

Rafters, L/ [DELTA] = 240)

RAFTERSPACING(inches) SPECIES AND GRADE DEAD LOAD = 10 pounds per square foot DEAD LOAD = 20 pounds per square foot
2 * 4 2 *6 2 * 8 2 *10 2 *12 2 *4 2 * 6 2 *8 2 * 10 2 * 12
Maximum rafter spans
(ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.) (ft. -in.)
12 Douglas Fir-Larch SS 7-8 12-1 15-11 20-3 24-8 7-8 12-1 15-11 20-3 24-0
Douglas Fir-Larch #1 7-5 11-7 15-3 18-7 21-7 7-5 11-2 14-1 17-3 20-0
Douglas Fir-Larch #2 7-3 11-3 14-3 17-5 20-2 7-1 10-5 13-2 16-1 18-8
Douglas Fir-Larch #3 5-10 8-6 10-9 13-2 15-3 5-5 7-10 10-0 12-2 14-1
Hem-Fir SS 7-3 11-5 15-0 19-2 23-4 7-3 11-5 15-0 19-2 23-4
Hem-Fir #1 7-1 11-2 14-8 18-1 21-0 7-1 10-10 13-9 16-9 19-5
Hem-Fir #2 6-9 10-8 14-0 17-2 19-11 6-9 10-3 13-0 15-10 18-5
Hem-Fir #3 5-10 8-6 10-9 13-2 15-3 5-5 7-10 10-0 12-2 14-1
Southern Pine SS 7-6 11-0 15-7 19-11 24-3 7-6 11-10 15-7 19-11 24-3
Southern Pine #1 7-5 11-7 15-4 19-7 23-9 7-5 11-7 15-4 18-9 22-4
Southern Pine #2 7-3 11-5 15-0 18-2 21-3 7-3 10-11 14-1 16-10 19-9
Southern Pine #3 6-2 9-2 11-8 13-9 16-4 5-9 8-5 10-9 12-9 15-2
Spruce-Pine-Fir SS 7-1 11-2 14-8 18-9 22-10 7-1 11-2 14-8 18-9 22-4
Spruce-Pine-Fir #1 6-11 10-11 14-3 17-5 20-2 6-11 10-5 13-2 16-1 18-8
Spruce-Pine-Fir #2 6-11 10-11 14-3 17-5 20-2 6-11 10-5 13-2 16-1 18-8
Spruce-Pine-Fir #3 5-10 8-6 10-9 13-2 15-3 5-5 7-10 10-0 12-2 14-1
16 Douglas Fir-Larch SS 7-0 11-0 14-5 18-5 22-5 7-0 11-0 14-5 17-11 20-10
Douglas Fir-Larch #1 6-9 10-5 13-2 16-1 18-8 6-7 9-8 12-2 14-11 17-3
Douglas Fir-Larch #2 6-7 9-9 12-4 15-1 17-6 6-2 9-0 11-5 13-11 16-2
Douglas Fir-Larch #3 5-0 7-4 9-4 11-5 13-2 4-8 6-10 8-8 10-6 12-3
Hem-Fir SS 6-7 10-4 13-8 17-5 21-2 6-7 10-4 13-8 17-5 20-5
Hem-Fir #1 6-5 10-2 12-10 15-8 18-2 6-5 9-5 11-11 14-6 16-10
Hem-Fir #2 6-2 9-7 12-2 14-10 17-3 6-1 8-11 11-3 13-9 15-11
Hem-Fir #3 5-0 7-4 9-4 11-5 13-2 4-8 6-10 8-8 10-6 12-3
Southern Pine SS 6-10 10-9 14-2 18-1 22-0 6-10 10-9 14-2 18-1 22-0
Southern Pine #1 6-9 10-7 13-11 17-6 20-11 6-9 10-7 13-8 16-2 19-4
Southern Pine #2 6-7 10-2 13-2 15-9 18-5 6-7 9-5 12-2 14-7 17-1
Southern Pine #3 5-4 7-11 10-1 11-11 14-2 4-11 7-4 9-4 11-0 13-1
Spruce-Pine-Fir SS 6-5 10-2 13-4 17-0 20-9 6-5 10-2 13-4 16-8 19-4
Spruce-Pine-Fir #1 6-4 9-9 12-4 15-1 17-6 6-2 9-0 11-5 13-11 16-2
Spruce-Pine-Fir #2 6-4 9-9 12-4 15-1 17-6 6-2 9-0 11-5 13-11 16-2
Spruce-Pine-Fir #3 5-0 7-4 9-4 11-5 13-2 4-8 6-10 8-8 10-6 12-3
19.2 Douglas Fir-Larch SS 6-7 10-4 13-7 17-4 20-6 6-7 10-4 13-5 16-5 19-0
Douglas Fir-Larch #1 6-4 9-6 12-0 14-8 17-1 6-0 8-10 11-2 13-7 15-9
Douglas Fir-Larch #2 6-1 8-11 11-3 13-9 15-11 5-7 8-3 10-5 12-9 14-9
Douglas Fir-Larch #3 4-7 6-9 8-6 10-5 12-1 4-3 6-3 7-11 9-7 11-2
Hem-Fir SS 6-2 9-9 12-10 16-5 19-11 6-2 9-9 12-10 16-1 18-8
Hem-Fir #1 6-1 9-3 11-9 14-4 16-7 5-10 8-7 10-10 13-3 15-5
Hem-Fir #2 5-9 8-9 11-1 13-7 15-9 5-7 8-1 10-3 12-7 14-7
Hem-Fir #3 4-7 6-9 8-6 10-5 12-1 4-3 6-3 7-11 9-7 11-2
Southern Pine SS 6-5 10-2 13-4 17-0 20-9 6-5 10-2 13-4 17-0 20-9
Southern Pine #1 6-4 9-11 13-1 16-0 19-1 6-4 9-11 12-5 14-10 17-8
Southern Pine #2 6-2 9-4 12-0 14-4 16-10 6-0 8-8 11-2 13-4 15-7
Southern Pine #3 4-11 7-3 9-2 10-10 12-11 4-6 6-8 8-6 10-1 12-0
Spruce-Pine-Fir SS 6-1 9-6 12-7 16-0 19-1 6-1 9-6 12-5 15-3 17-8
Spruce-Pine-Fir #1 5-11 8-11 11-3 13-9 15-11 5-7 8-3 10-5 12-9 14-9
Spruce-Pine-Fir #2 5-11 8-11 11-3 13-9 15-11 5-7 8-3 10-5 12-9 14-9
Spruce-Pine-Fir #3 4-7 6-9 8-6 10-5 12-1 4-3 6-3 7-11 9-7 11-2
24 Douglas Fir-Larch SS 6-1 9-7 12-7 15-10 18-4 6-1 9-6 12-0 14-8 17-0
Douglas Fir-Larch #1 5-10 8-6 10-9 13-2 15-3 5-5 7-10 10-0 12-2 14-1
Douglas Fir-Larch #2 5-5 7-11 10-1 12-4 14-3 5-0 7-4 9-4 11-5 13-2
Douglas Fir-Larch #3 4-1 6-0 7-7 9-4 10-9 3-10 5-7 7-1 8-7 10-0
Hem-Fir SS 5-9 9-1 11-11 15-12 18-0 5-9 9-1 11-9 14-5 16-8
Hem-Fir #1 5-8 8-3 10-6 12-10 14-10 5-3 7-8 9-9 11-10 13-9
Hem-Fir #2 5-4 7-10 9-11 12-1 14-1 4-11 7-3 9-2 11-3 13-0
Hem-Fir #3 4-1 6-0 7-7 9-4 10-9 3-10 5-7 7-1 8-7 10-0
Southern Pine SS 6-0 9-5 12-5 15-10 19-3 6-0 9-5 12-5 15-10 19-3
Southern Pine #1 5-10 9-3 12-0 14-4 17-1 5-10 8-10 11-2 13-3 15-9
Southern Pine #2 5-9 8-4 10-9 12-10 15-1 5-5 7-9 10-0 11-11 13-11
Southern Pine #3 4-4 6-5 8-3 9-9 11-7 4-1 6-0 7-7 9-0 10-8
Spruce-Pine-Fir SS 5-8 8-10 11-8 14-8 17-1 5-8 8-10 11-2 13-7 15-9
Spruce-Pine-Fir #1 5-5 7-11 10-1 12-4 14-3 5-0 7-4 9-4 11-5 13-2
Spruce-Pine-Fir #2 5-5 7-11 10-1 12-4 14-3 5-0 7-4 9-4 11-5 13-2
Spruce-Pine-Fir #3 4-1 6-0 7-7 9-4 10-9 3-10 5-7 7-1 8-7 10-0

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 47.9 N/m2 .

TABLE 2308.10. 4.1

RAFTER TIE CONNECTIONSSg

RAFTER SLOPE TIESPACING(inches) NO SNOW LOAD GROUND SNOW LOAD (pound per square foot)
30 pounds per square foot 50 pounds per square foot
Roof span (feet)
12 20 28 36 12 20 28 36 12 20 28 36
Required number of 16d common (3 ½" x 0.162 ") nailsa, b per connectionc, d, e, f
3:12 12 4 6 8 10 4 6 8 11 5 8 12 15
16 5 7 10 13 5 8 11 14 6 11 15 20
24 7 11 15 19 7 11 16 21 9 16 23 30
32 10 14 19 25 10 16 22 28 12 27 30 40
48 14 21 29 37 14 32 36 42 18 32 46 60
4:12 12 3 4 5 6 3 5 6 8 4 6 9 11
16 3 5 7 8 4 6 8 11 5 8 12 15
24 4 7 10 12 5 9 12 16 7 12 17 22
32 6 9 13 16 8 12 16 22 10 16 24 30
48 8 14 19 24 10 18 24 32 14 24 34 44
5:12 12 3 3 4 5 3 4 5 7 3 5 7 9
16 3 4 5 7 3 5 7 9 4 7 9 12
24 4 6 8 10 4 7 10 13 6 10 14 18
32 5 8 10 13 6 10 14 18 8 14 18 24
48 7 11 15 20 8 14 20 26 12 20 28 36
7:12 12 3 3 3 4 3 3 4 5 3 4 5 7
16 3 3 4 5 3 4 5 6 3 5 7 9
24 3 4 6 7 3 5 7 9 4 7 10 13
32 4 6 8 10 4 8 10 12 6 10 14 18
48 5 8 11 14 6 10 14 18 9 14 20 26
9:12 12 3 3 3 3 3 3 3 4 3 3 4 5
16 3 3 3 4 3 3 4 5 3 4 5 7
24 3 3 5 6 3 4 6 7 3 6 8 10
32 3 4 6 8 4 6 8 10 5 8 10 14
48 4 6 9 11 5 8 12 14 7 12 16 20
12:12 12 3 3 3 3 3 3 3 3 3 3 3 4
16 3 3 3 3 3 3 3 4 3 3 4 5
24 3 3 3 4 3 3 4 6 3 4 6 8
32 3 3 4 5 3 5 6 8 4 6 8 10
48 3 4 6 7 4 7 8 12 6 8 12 16

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 47.8 N/m2.

a. 40d box (5" x 0.162 ") or l6d sinker (31/4" x 0.148 ") nails are permitted to be substituted for 16d common (3 ½" x 0.16 ") nails.

b. Nailing requirements are permitted to be reduced 25 percent if nails are clinched.

c. Rafter tie heel joint connections are not required where the ridge is supported by a load-bearing wall, header or ridge beam.

d. When intermediate support of the rafter is provided by vertical struts or purlins to a load-bearing wall, the tabulated heel joint connection requirements are permitted to be reduced proportionally to the reduction in span.

e. Equivalent nailing patterns are required for ceiling joist to ceiling joist lap splices.

f. Connected members shall be of sufficient size to prevent splitting due to nailing.

g. For snow loads less than 30 pounds per square foot, the required number of nails is permitted to be reduced by multiplying by the ratio of actual snow load plus 10 divided by 40, but not less than the number required for no snow load.

2308.10. 4.2 Notches and holes. Notching at the ends of rafters or ceiling joists shall not exceed one-fourth the depth. Notches in the top or bottom of the rafter or ceiling joist shall not exceed one-sixth the depth and shall not be located in the middle one-third of the span, except that a notch not exceeding one-third of the depth is permitted in the top of the rafter or ceiling joist not further from the face of the support than the depth of the member.

Holes bored in rafters or ceiling joists shall not be within 2 inches (51 mm) of the top and bottom and their diameter shall not exceed one-third the depth of the member.

2308.10. 4.3 Framing around openings. Trimmer and header rafters shall be doubled, or of lumber of equivalent cross section, where the span of the header exceeds 4 feet (1219 mm). The ends of header rafters more than 6 feet (1829 mm) long shall be supported by framing anchors or rafter hangers unless bearing on a beam, partition or wall.

2308.10.5 Purlins. Purlins to support roof loads are permitted to be installed to reduce the span of rafters within allowable limits and shall be supported by struts to bearing walls. The maximum span of 2-inch by 4-inch (51 mm by 102 mm) purlins shall be 4 feet (1219 mm). The maximum span of the 2-inch by 6-inch (51 mm by 152 mm) purlin shall be 6 feet (1829 mm), but in no case shall the purlin be smaller than the supported rafter. Struts shall not be smaller than 2-inch by 4-inch (51 mm by 102 mm) members. The unbraced length of struts shall not exceed 8 feet (2438 mm) and the minimum slope of the struts shall not be less than 45 degrees ( 0.79 rad) from the horizontal.

2308.10.6 Blocking. Roof rafters and ceiling joists shall be supported laterally to prevent rotation and lateral displacement in accordance with the provisions of Section 2308.8.5.

2308.10.7 Engineered wood products. Prefabricated wood I-joists, structural glued-laminated timber and structural composite lumber shall not be notched or drilled except where permitted by the manufacturer's recommendations or where the effects of such alterations are specifically considered in the design of the member by a registered design professional.

2308.10.8 Roof sheathing. Roof sheathing shall be in accordance with Tables 2304.7(3) and 2304.7(5) for wood structural panels, and Tables 2304.7(1) and 2304.7(2) for lumber and shall comply with Section 2304.7.2.

2308.10. 8.1 Joints. Joints in lumber sheathing shall occur over supports unless approved end-matched lumber is used, in which case each piece shall bear on at least two supports.

2308.10.9 Roof planking. Planking shall be designed in accordance with the general provisions of this code.

In lieu of such design, 2-inch (51 mm) tongue-and groove planking is permitted in accordance with Table 2308.10.9. Joints in such planking are permitted to be randomly spaced, provided the system is applied to not less than three continuous spans, planks are center matched and end matched or splined, each plank bears on at least one support, and joints are separated by at least 24 inches (610 mm) in adjacent pieces.

2308.10.10 Wood trusses. Wood trusses shall be designed in accordance with Section 2303.4.

2308.10.11 Attic ventilation. For attic ventilation, see Section 1203.2.

2308.11 Additional requirements for conventional construction in Seismic Design Category B or C. Structures of conventional light-frame construction in Seismic Design Category B or C, as determined in Section 1613, shall comply with Sections 2308.11.1 through 2308.11.3, in addition to the provisions of Sections 2308.1 through 2308.10.

2308.11.1 Number of stories. Structures of conventional light-frame construction shall not exceed two stories above grade plane in Seismic Design Category C.

2308.11.2 Concrete or masonry. Concrete or masonry walls and stone or masonry veneer shall not extend above a basement.

Exceptions:

1. Stone and masonry veneer is permitted to be used in the first two stories above grade plane or the first three stories above grade plane where the lowest story has concrete or masonry walls in Seismic Design Category B, provided that structural use panel wall bracing is used and the length of bracing provided is one-and one-half times the required length as determined in Table 2308.9.3(1).

2. Stone and masonry veneer is permitted to be used in the first story above grade plane or the first two stories above grade plane where the lowest story has concrete or masonry walls in Seismic Design Category B or C.

3. Stone and masonry veneer is permitted to be used in both stories of buildings with two stories above grade plane in Seismic Design Categories B and C, provided the following criteria are met:

3.1Type of brace per Section 2308.9.3 shall be Method 3 and the allowable shear capacity in accordance with Table 2306.3 shall be a minimum of 350 plf (5108 N/m).

3.2Braced wall panels in the second story shall be located in accordance with Section 2308.9.3 and not more than 25 feet (7620 mm) on center, and the total length of braced wall panels shall be not less than 25 percent of the braced wall line length. Braced wall panels in the first story shall be located in accordance with Section 2308.9.3 and not more than 25 feet (7620 mm) on center, and the total length of braced wall panels shall be not less than 45 percent of the braced wall line length.

3.3Hold-down connectors shall be provided at the ends of each braced wall panel for the allowable design of 2,000 pounds (8896 N). Hold-down connectors shall be provided at the ends of each braced wall panel for the first story to foundation connection with an allowable capacity of 3,900 pounds (17 347 N). In all cases, the hold-down connector force shall be transferred to the foundation.

3.4Cripple walls shall not be permitted.

2308.11.3 Framing and connection details. Framing and connection details shall conform to Sections 2308.11. 3.1 through 2308.11. 3.3.

TABLE 2308.10.9 ALLOWABLE SPANS FOR 2-INCH TONGUE-AND-GROOVE DECKING

SPANa(feet) LIVE LOAD (pound per square foot) DEFLECTION LIMIT BENDING STRESS (f) (pound per square inch) MODULUS OF ELASTICITY (E) (pound per square inch)
Roofs
4 20 1/240 160 170,000
1/360 256,000
30 1/240 210 256,000
1/360 384,000
40 1/240 270 340,000
1/360 512,000
4.5 20 1/240 200 242,000
1/360 305,000
30 1/240 270 363,000
1/360 405,000
40 1/240 350 484,000
1/360 725,000
5.0 20 1/240 250 332,000
1/360 500,000
30 1/240 330 495,000
1/360 742,000
40 1/240 420 660,000
1/360 1,000,000
5.5 20 1/240 300 442,000
1/360 660,000
30 1/240 400 662,000
1/360 998,000
40 1/240 500 884,000
1/360 1,330,000
6.0 20 1/240 360 575,000
1/360 862,000
30 1/240 480 862,000
1/360 1,295,000
40 1/240 600 1,150,000
1/360 1,730,000
6.5 20 1/240 420 595,000
1/360 892,000
30 1/240 560 892,000
1/360 1,340,000
40 1/240 700 1,190,000
1/360 1,730,000
7.0 20 1/240 490 910,000
1/360 1,360,000
30 1/240 650 1,370,000
1/360 2,000,000
40 1/240 810 1,820,000
1/360 2,725,000
7.5 20 1/240 560 1,125,000
1/360 1,685,000
30 1/240 750 1,685,000
1/360 2,530,000
40 1/240 930 2,250,000
1/360 3,380,000
8.0 20 1/240 640 1,360,000
1/360 2,040,000
30 1/240 850 2,040,000
1/360 3,060,000
Floors
4       840 1,000,000
4.5 40 1/360 950 1,300,000
5.0       1,060 1,600,000

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kN/m2 , 1 poundper square inch = 0.00689 N/mm2 .

a. Spans are based on simple beam action with 10 pounds per square foot dead load and provisions for a 300-pound concentrated load on a 12-inch width of decking. Random layup is permitted in accordance with the provisions of Section 2308.10.9. Lumber thickness is 1 ½ inches nominal.

2308.11. 3.1 Anchorage. Braced wall lines shall be anchored in accordance with Section 2308.6 at foundations.

2308.11. 3.2 Stepped footings. Where the height of a required braced wall panel extending from foundation to floor above varies more than 4 feet (1219 mm), the following construction shall be used:

1. Where the bottom of the footing is stepped and the lowest floor framing rests directly on a sill bolted to the footings, the sill shall be anchored as required in Section 2308.3.3.

2. Where the lowest floor framing rests directly on a sill bolted to a footing not less than 8 feet (2438 mm) in length along a line of bracing, the line shall be considered to be braced. The double plate of the cripple stud wall beyond the segment of footing extending to the lowest framed floor shall be spliced to the sill plate with metal ties, one on each side of the sill and plate. The metal ties shall not be less than 0.058 inch [ 1.47 mm (16 galvanized gage)] by 1½ inches (38 mm) wide by 48 inches (1219 mm) with eight 16d common nails on each side of the splice location (see Figure 2308.11. 3.2 ). The metal tie shall have a minimum yield of 33,000 pounds per square inch (psi) (227 MPa).

3. Where cripple walls occur between the top of the footing and the lowest floor framing, the bracing requirements for a story shall apply.

2308.11. 3.3 Openings in horizontal diaphragms.

Openings in horizontal diaphragms with a dimension perpendicular to the joist that is greater than 4 feet (1219 mm) shall be constructed in accordance with the following:

1. Blocking shall be provided beyond headers.

2. Metal ties not less than 0.058 inch [ 1.47 mm (16 galvanized gage)] by 1½ inches (38 mm) wide with eight 16d common nails on each side of the header-joist intersection shall be provided (see Figure 2308.11. 3.3 ). The metal ties shall have a minimum yield of 33,000 psi (227 MPa).

2308.12 Additional requirements for conventional construction in Seismic Design Category D or E. Structures of conventional light-frame construction in Seismic Design Category D or E, as determined in Section 1613, shall conform to Sections 2308.12.1 through 2308.12.9, in addition to the requirements for Seismic Design Category B or C in Section 2308.11.

2308.12.1 Number of stories. Structures of conventional light-frame construction shall not exceed one story above grade plane in Seismic Design Category D or E.

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-7.jpg

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

FIGURE 2308.11. 3.2

STEPPED FOOTING CONNECTION DETAILS

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-8.jpg

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

FIGURE 2308.11. 3.3

OPENINGS IN HORIZONTAL DIAPHRAGMS

2308.12.2 Concrete or masonry. Concrete or masonry walls and stone or masonry veneer shall not extend above a basement.

Exception: Stone and masonry veneer is permitted to be used in the first story above grade plane in Seismic Design Category D, provided the following criteria are met:

1. Type of brace in accordance with Section 2308.9.3 shall be Method 3 and the allowable shear capacity in accordance with Table 2306.3 shall be a minimum of 350 plf (5108 N/m).

2. The bracing of the first story shall be located at each end and at least every 25 feet (7620 mm) o.c. but not less than 45 percent of the braced wall line.

3. Hold-down connectors shall be provided at the ends of braced walls for the first floor to foundation with an allowable capacity of 2,100 pounds (9341 N).

4. Cripple walls shall not be permitted.

2308.12.3 Braced wall line spacing. Spacing between interior and exterior braced wall lines shall not exceed 25 feet (7620 mm).

2308.12.4 Braced wall line sheathing. Braced wall lines shall be braced by one of the types of sheathing prescribed by Table 2308.12.4 as shown in Figure 2308.9.3. The sum of lengths of braced wall panels at each braced wall line shall conform to Table 2308.12.4. Braced wall panels shall be distributed along the length of the braced wall line and start at not more than 8 feet (2438 mm) from each end of the braced wall line. Panel sheathing joints shall occur over studs or blocking. Sheathing shall be fastened to studs, top and bottom plates and at panel edges occurring over blocking. Wall framing to which sheathing used for bracing is applied shall be nominal 2 inch wide [actual 11/2 inch (38mm)]orlarger members.

Cripple walls having a stud height exceeding 14 inches (356 mm) shall be considered a story for the purpose of this section and shall be braced as required for braced wall lines in accordance with Table 2308.12.4. Where interior braced wall lines occur without a continuous foundation below, the length of parallel exterior cripple wall bracing shall be one and one-half times the lengths required by Table 2308.12.4. Where the cripple wall sheathing type used is Type S-W and this additional length of bracing cannot be provided, the capacity of Type S-W sheathing shall be increased by reducing the spacing of fasteners along the perimeter of each piece of sheathing to 4 inches (102 mm) o.c.

2308.12.5 Attachment of sheathing. Fastening of braced wall panel sheathing shall not be less than that prescribed in Table 2308.12.4 or 2304.9.1. Wall sheathing shall not be attached to framing members by adhesives.

2308.12.6 Irregular structures. Conventional light-frame construction shall not be used in irregular portions of structures in Seismic Design Category D or E. Such irregular portions of structures shall be designed to resist the forces specified in Chapter 16 to the extent such irregular features affect the performance of the conventional framing system. A portion of a structure shall be considered to be irregular where one or more of the conditions described in Items 1 through 6 below are present.

1. Where exterior braced wall panels are not in one plane vertically from the foundation to the uppermost story in which they are required, the structure shall be considered to be irregular [see Figure 2308.12.6(1)].

Exception: Floors with cantilevers or setbacks not exceeding four times the nominal depth of the floor joists [see Figure 2308.12.6(2)] are permitted to support braced wall panels provided:

1. Floor joists are 2 inches by 10 inches (51 mm by 254 mm) or larger and spaced not more than 16 inches (406 mm) o.c.

2. The ratio of the back span to the cantilever is at least 2:1.

3. Floor joists at ends of braced wall panels are doubled.

4. A continuous rim joist is connected to the ends of cantilevered joists. The rim joist is permitted to be spliced using a metal tie not less than 0.058 inch ( 1.47 mm) (16 galvanized gage) and 1½ inches (38 mm) wide fastened with six 16d common nails on each side. The metal tie shall have a minimum yield of 33,000 psi (227 MPa).

5. Joists at setbacks or the end of cantilevered joists shall not carry gravity loads from more than a single story having uniform wall and roof loads, nor carry the reactions from headers having a span of 8 feet (2438 mm) or more.

2. Where a section of floor or roof is not laterally supported by braced wall lines on all edges, the structure shall be considered to be irregular [see Figure 2308.12.6(3)].

Exception: Portions of roofs or floors that do not support braced wall panels above are permitted to extend up to 6 feet (1829 mm) beyond a braced wall line [see Figure 2308.12.6(4)].

3. Where the end of a required braced wall panel extends more than 1 foot (305 mm) over an opening in the wall below, the structure shall be considered to be irregular. This requirement is applicable to braced wall panels offset in plane and to braced wall panels offset out of plane as permitted by the exception to Item 1 above in this section [see Figure 2308.12.6(5)].

Exception: Braced wall panels are permitted to extend over an opening not more than 8 feet (2438 mm) in width where the header is a 4-inch by 12-inch (102 mm by 305 mm) or larger member.

4. Where portions of a floor level are vertically offset such that the framing members on either side of the offset cannot be lapped or tied together in an approved manner, the structure shall be considered to be irregular [see Figure 2308.12.6(6)].

Exception: Framing supported directly by foundations need not be lapped or tied directly together.

5. Where braced wall lines are not perpendicular to each other, the structure shall be considered to be irregular [see Figure 2308.12.6(7)].

6. Where openings in floor and roof diaphragms having a maximum dimension greater than 50 percent of the distance between lines of bracing or an area greater than 25 percent of the area between orthogonal pairs of braced wall lines are present, the structure shall be considered to be irregular [see Figure 2308.12.6(8)].

TABLE 2308.12.4

WALL BRACING IN SEISMIC DESIGN CATEGORIES D AND E

(Minimum Length of Wall Bracing per each 25 Linear Feet of Braced Wall

Line a)

CONDITION SHEATHING TYPEb SDS <0.50 0.50< SDS <0.75 0.75<= SDS <=1.00 SDS >1.00
One story G-Pc 10 feet 8 inches 14 feet 8 inches 18 feet 8 inches 25 feet 0 inches
S-W 5 feet 4 inches 8 feet 0 inches 9 feet 4 inches 12 feet 0 inches

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

a. Minimum length of panel bracing of one face of the wall for S-W sheathing or both faces of the wall for G-P sheathing; h/w ratio shall not exceed 2:1. For S-W panel bracing of the same material on two faces of the wall, the minimum length is permitted to be one-half the tabulated value but the h/w ratio shall not exceed 2:1 and design for uplift is required.

b. G-P = gypsum board, fiberboard, particleboard, lath and plaster or gypsum sheathing boards; S-W = wood structural panels and diagonal wood sheathing.

c. Nailing as specified below shall occur at all panel edges at studs, at top and bottom plates and, where occurring, at blocking:

For ½-inch gypsum board, 5d ( 0.113 inch diameter) cooler nails at 7 inches on center;

For 5/8-inch gypsum board, No. 11 gage ( 0.120 inch diameter) at 7 inches on center;

For gypsum sheathing board, 1 3/4 inches long by 7/16-inch head, diamond point galvanized nails at 4 inches on center;

For gypsum lath, No. 13 gage ( 0.092 inch) by 1 1/8 inches long, 19 /64-inch head, plasterboard at 5 inches on center;

For Portland cement plaster, No. 11 gage ( 0.120 inch) by 1 1/2 inches long, 7/16- inch head at 6 inches on center;

For fiberboard and particleboard, No. 11 gage ( 0.120 inch) by 1 1/2 inches long, 7/16-inch head, galvanized nails at 3 inches on center.

2308.12.7 Anchorage of exterior means of egress components. Exterior egress balconies, exterior exit stairways and similar means of egress components shall be positively anchored to the primary structure at not over 8 feet (2438 mm) o.c. or shall be designed for lateral forces. Such attachment shall not be accomplished by use of toenails or nails subject to withdrawal.

2308.12.8 Sill plate anchorage. Sill plates shall be anchored with anchor bolts with steel plate washers between the foundation sill plate and the nut, or approved anchor straps load rated in accordance with Section 1716.1. Such washers shall be a minimum of 0.229 inch by 3 inches by 3 inches ( 5.82 mm by 76 mm by 76 mm) in size. The hole in the plate washer is permitted to bediagonally slotted with a width of up to 3 /16 inch ( 4.76 mm) larger than thebolt diameter and a slot length not to exceed 1 3 /4 inches (44 mm), provided a standard cut washer is placed between the plate washer and the nut.

2308.12.9 Sill plate anchorage in Seismic Design Category E. Steel boltswith a minimum nominal diameter of 5 /8 inch ( 15.9 mm) or approved

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-9.jpg

foundation anchor straps load rated in accordance with Section 1716.1 and spaced to provide equivalent anchorage shall be used in Seismic Design Category E.

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-10.jpg

For SI: 1 foot = 304.8 mm.

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-11.jpg

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-12.png

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-13.jpg

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-14.jpg

For SI: 1 foot = 304.8 mm.

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-15.png

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-16.jpg

image: oh/admin/2014/4101$1-23-01_ph_ff_n_ru_20110418_1139-17.png

Replaces: 4101:1-23-01

Effective: 11/01/2011
R.C. 119.032 review dates: 11/01/2016
Promulgated Under: 119.03
Statutory Authority: 3781.10(A)
Rule Amplifies: 3781.10 , 3781.11 , 3791.04
Prior Effective Dates: 3/1/05, 7/1/07