4101:3-11-01 Storm drainage.

[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 4101:3-13-01 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 1101

GENERAL

1101.1 Scope. The provisions of this chapter shall govern the materials, design, construction and installation of storm drainage.

1101.2 Where required. All roofs, paved areas, yards, courts and courtyards in buildings shall drain into a separate storm sewer system, or a combined sewer system, or to an approved place of disposal. For one-and two-, and three- family dwellings, and where approved, storm water is permitted to discharge onto flat areas, such as streets or lawns, provided that the storm water flows away from the building.

1101.3 Prohibited drainage. Storm water shall not be drained into sewers intended for sewage only.

1101.4 Tests. The conductors and the building storm drain shall be tested in accordance with Section 312.

1101.5 Change in size. The size of a drainage pipe shall not be reduced in the direction of flow.

1101.6 Fittings and connections. All connections and changes in direction of the storm drainage system shall be made with approved drainage-type fittings in accordance with Table 706.3. The fittings shall not obstruct or retard flow in the system.

1101.7 Roof design. Roofs shall be designed for the maximum possible depth of water that will pond thereon as determined by the relative levels of roof deck and overflow weirs, scuppers, edges or serviceable drains in combination with the deflected structural elements. In determining the maximum possible depth of water, all primary roof drainage means shall be assumed to be blocked.

1101.8 Cleanouts required. Cleanouts shall be installed in the storm drainage system and shall comply with the provisions of this code for sanitary drainage pipe cleanouts.

Exception: Subsurface drainage system.

1101.9 Backwater valves. Storm drainage systems shall be provided with backwater valves as required for sanitary drainage systems in accordance with Section 715.

SECTION 1102

MATERIALS

1102.1 General. The materials and methods utilized for the construction and installation of storm drainage systems shall comply with this section and the applicable provisions of Chapter 7.

1102.2 Inside storm drainage conductors. Inside storm drainage conductors installed above ground shall conform to one of the standards listed in Table 702.1.

1102.3 Underground building storm drain pipe. Underground building storm drain pipe shall conform to one of the standards listed in Table 702.2.

1102.4 Building storm sewer pipe. Building storm sewer pipe shall conform to one of the standards listed in Table 1102.4.

TABLE 1102.4

BUILDING STORM SEWER PIPE

MATERIAL STANDARD
Acrylonitrile butadiene styrene (ABS) plastic pipe ASTM D 2661; ASTM D 2751; ASTM F 628; CAN/CSA B 181.1; CAN/CSA B 182.1
Asbestos-cement pipe ASTM C 428
Cast-iron pipe ASTM A 74; ASTM A 888; CISPI 301
Concrete pipe ASTM C 14; ASTM C 76; CAN/CSA A 257.1 M; CAN/CSA A 257.2 M
Copper or copper-alloy tubing (Type K, L, M or DWV) ASTM B 75; ASTM B 88; ASTM B 251; ASTM B 306
Polyethylene (PE) plastic pipe ASTM F 2306/F 2306M
Polyvinyl chloride (PVC) plastic pipe (Type DWV, SDR26, SDR35, SDR41, PS50 or PS100) ASTM D 2665; ASTM D 3034; ASTM F 891; CSA B 182.4; CSA B 181.2; CSA B 182.2
Vitrified clay pipe ASTM C 4; ASTM C 700
Stainless steel drainage systems, Type 316L ASME A 112.3.1

1102.5 Subsoil drain pipe. Subsoil drains shall be open-jointed, horizontally split or perforated pipe conforming to one of the standards listed in Table 1102.5.

TABLE 1102.5

SUBSOIL DRAIN PIPE

MATERIAL STANDARD
Asbestos-cement pipe ASTM C 508
Cast-iron pipe ASTM A 74; ASTM A 888; CISPI 301
Polyethylene (PE) plastic pipe ASTM F 405; CAN/CSA B 182.1; CSA B 182.6; CSA B 182.8
Polyvinyl chloride (PVC) Plastic pipe (type sewer pipe, PS25, PS50 or PS100) ASTM D 2729; ASTM F 891; CSA B 182.2; CAN/CSA B 182.4
Stainless steel drainage systems, Type 316L ASME A 112.3.1
Vitrified clay pipe ASTM C 4; ASTM C 700

1102.6 Roof drains. Roof drains shall conform to ASME A 112.21.2M or ASME A 112.3.1.

1102.7 Fittings. Pipe fittings shall be approved for installation with the piping material installed, and shall conform to the respective pipe standards or one of the standards listed in Table 1102.7. The fittings shall not have ledges, shoulders or reductions capable of retarding or obstructing flow in the piping. Threaded drainage pipe fittings shall be of the recessed drainage type.

TABLE 1102.7

PIPE FITTINGS

MATERIAL STANDARD
Acrylonitrile butadiene styrene (ABS) plastic ASTM D 2661; ASTM D 3311; CSA B 181.1
Cast-iron ASME B 16.4; ASME B 16.12; ASTM A 888; CISPI 301; ASTM A 74
Coextruded composite ABS sewer and drain DR-PS in PS35, PS50, PS100, PS140, PS200 ASTM D 2751
Coextruded composite ABS DWV Schedule 40 IPS pipe (solid or cellular core) ASTM D 2661; ASTM D 3311; ASTM F 628
Coextruded composite PVC DWV Schedule 40 IPSDR, PS140, PS200 (solid or cellular core) ASTM D 2665; ASTM D 3311; ASTM F 891
Coextruded composite PVC sewer and drain DR-PS in PS35, PS50, PS100, PS140, PS200 ASTM D 3034
Copper or copper alloy ASME B 16.15; ASME B 16.18; ASME B 16.22;
   ASME B 16.23; ASME B 16.26; ASME B 16.29
Gray iron and ductile iron AWWA C110
Malleable iron ASME B 16.3
Plastic, general ASTM F 409
Polyethylene (PE) plastic pipe ASTM F 2306/F 2306M
Polyvinyl chloride (PVC) plastic ASTM D 2665; ASTM D 3311; ASTM F 1866
Steel ASME B 16.9; ASME B 16.11; ASME B 16.28
Stainless steel drainage systems, Type 316L ASME A 112.3.1

SECTION 1103

TRAPS

1103.1 Main trap. Leaders and storm drains connected to a combined sewer shall be trapped. Individual storm water traps shall be installed on the storm water drain branch serving each conductor, or a single trap shall be installed in the main storm drain just before its connection with the combined building sewer or the public sewer.

1103.2 Material. Storm water traps shall be of the same material as the piping system to which they are attached.

1103.3 Size. Traps for individual conductors shall be the same size as the horizontal drain to which they are connected.

1103.4 Cleanout. An accessible cleanout shall be installed on the building side of the trap.

SECTION 1104

CONDUCTORS AND CONNECTIONS

1104.1 Prohibited use. Conductor pipes shall not be used as soil, waste or vent pipes, and soil, waste or vent pipes shall not be used as conductors.

1104.2 Combining storm with sanitary drainage. The sanitary and storm drainage systems of a structure shall be entirely separate except where combined sewer systems are utilized. Where a combined sewer is utilized, the building storm drain shall be connected to the sanitary sewer exterior to the building.

1104.3 Floor drains. Floor drains shall not be connected to a storm drain.

SECTION 1105

ROOF DRAINS

1105.1 Strainers. Roof drains shall have strainers extending not less than 4 inches (102 mm) above the surface of the roof immediately adjacent to the roof drain. Strainers shall have an available inlet area, above roof level, of not less than one and one-half times the area of the conductor or leader to which the drain is connected.

1105.2 Flat decks. Roof drain strainers for use on sun decks, parking decks and similar areas that are normally serviced and maintained shall comply with Section 1105.1 or shall be of the flat-surface type, installed level with the deck, with an available inlet area not less than two times the area of the conductor or leader to which the drain is connected.

1105.3 Roof drain flashings. The connection between roofs and roof drains which pass through the roof and into the interior of the building shall be made water-tight by the use of approved flashing material.

SECTION 1106

SIZE OF CONDUCTORS, LEADERS AND STORM DRAINS

1106.1 General. The size of the vertical conductors and leaders, building storm drains, building storm sewers, and any horizontal branches of such drains or sewers shall be based on the 100-year hourly rainfall rate indicated in Figure 1106.1 or on other rainfall rates determined from approved local weather data.


 image: oh/admin/2014/4101$3-11-01_ph_ff_n_ru_20110418_1149-1.jpg

FIGURE 1106.1

100-YEAR, 1-HOUR RAINFALL (INCHES) EASTERN UNITED STATES

For SI: 1 inch = 25.4 mm.

Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington D.C.

TABLE 1106.2(1)

SIZE OF CIRCULAR VERTICAL CONDUCTORS AND LEADERS

DIAMETEROFLEADER(inches)a HORIZONTALLY PROJECTED ROOF AREA (square feet)
Rainfall rate (inches per hour)
1 2 3 4 5 6 7 8 9 10 11 12
2 2,880 1,440 960 720 575 480 410 360 320 290 260 240
3 8,800 4,400 2,930 2,200 1,760 1,470 1,260 1,100 980 880 800 730
4 18,400 9,200 6,130 4,600 3,680 3,070 2,630 2,300 2,045 1,840 1,675 1,530
5 34,600 17,300 11,530 8,650 6,920 5,765 4,945 4,325 3,845 3,460 3,145 2,880
6 54,000 27,000 17,995 13,500 10,800 9,000 7,715 6,750 6,000 5,400 4,910 4,500
8 116,000 58,000 38,660 29,000 23,200 19,315 16,570 14,500 12,890 11,600 10,545 9,600

For SI: 1 inch = 25.4 mm, 1 square foot = 0.0929 m2 .

a.Sizes indicated are the diameter of circular piping. This table is applicable to piping of other shapes, provided the cross-sectional shape fully encloses a circle of the diameter indicated in this table. For rectangular leaders, see Table 1106.2(2).Interpolation is permitted for pipe sizes that fall between those listed in this table.

TABLE 1106.2(2)

SIZE OF RECTANGULAR VERTICAL CONDUCTORS AND LEADERS

DIMENSIONSOFCOMMONLEADERSIZESwidth x length(inches)a HORIZONTALLY PROJECTED ROOF AREA (square feet)
Rainfall rate (inches per hour)
1 2 3 4 5 6 7 8 9 10 11 12
1 3/4 *2 ½ 3,410 1,700 1,130 850 680 560 480 420 370 340 310 280
2 *3 5,540 2,770 1,840 1,380 1,100 920 790 690 610 550 500 460
2 3/4 *4 1/4 12,830 6,410 4,270 3,200 2,560 2,130 1,830 1,600 1,420 1,280 1,160 1,060
3 *4 13,210 6,600 4,400 3,300 2,640 2,200 1,880 1,650 1,460 1,320 1,200 1,100
3 ½ *4 15,900 7,950 5,300 3,970 3,180 2,650 2,270 1,980 1,760 1,590 1,440 1,320
3 ½ *5 21,310 10,650 7,100 5,320 4,260 3,550 3,040 2,660 2,360 2,130 1,930 1,770
3 3/4 *4 3/4 21,960 10,980 7,320 5,490 4,390 3,660 3,130 2,740 2,440 2,190 1,990 1,830
3 3/4 *5 1/4 25,520 12,760 8,500 6,380 5,100 4,250 3,640 3,190 2,830 2,550 2,320 2,120
3 ½ *6 27,790 13,890 9,260 6,940 5,550 4,630 3,970 3,470 3,080 2,770 2,520 2,310
4 *6 32,980 16,490 10,990 8,240 6,590 5,490 4,710 4,120 3,660 3,290 2,990 2,740
5 ½ *5 ½ 44,300 22,150 14,760 11,070 8,860 7,380 6,320 5,530 4,920 4,430 4,020 3,690
7 ½ *7 ½ 100,500 50,250 33,500 25,120 20,100 16,750 14,350 12,560 11,160 10,050 9,130 8,370

a. Sizes indicated are nominal width * length of the opening for rectangular piping.

b. For shapes not included in this table, Equation 11-1 shall be used to determine the equivalent circular diameter, De, of rectangular piping for use in interpolation using the data from Table 1106.2(1).

De, = [width * length] 1/2 (Equation 11-1)

where:

De = equivalent circular diameter and De, width and length are in inches.

1106.2 Vertical conductors and leaders. Vertical conductors and leaders shall be sized for the maximum projected roof area, in accordance with Tables 1106.2(1) and 1106.2(2).

1106.3 Building storm drains and sewers. The size of the building storm drain, building storm sewer and their horizontal branches having a slope of one-half unit or less vertical in 12 units horizontal (4-percent slope) shall be based on the maximum projected roof area in accordance with Table 1106.3. The minimum slope of horizontal branches shall be one-eighth unit vertical in 12 units horizontal (1-percent slope) unless otherwise approved.

1106.4 Vertical walls. In sizing roof drains and storm drainage piping, one-half of the area of any vertical wall that diverts rainwater to the roof shall be added to the projected roof area for inclusion in calculating the required size of vertical conductors, leaders and horizontal storm drainage piping.

1106.5 Parapet wall scupper location. Parapet wall roof drainage scupper and overflow scupper location shall comply with the requirements of the building code.

1106.6 Size of roof gutters. The size of semicircular gutters shall be based on the maximum projected roof area in accordance with Table 1106.6.

SECTION 1107

SECONDARY (EMERGENCY) ROOF DRAINS

1107.1 Secondary drainage required. Secondary (emergency) roof drains or scuppers shall be provided where the roof perimeter construction extends above the roof in such a manner that water will be entrapped if the primary drains allow buildup for any reason.

1107.2 Separate systems required. Secondary roof drain systems shall have the end point of discharge separate from the primary system. Discharge shall be above grade, in a location that would normally be observed by the building occupants or maintenance personnel.

1107.3 Sizing of secondary drains. Secondary (emergency) roof drain systems shall be sized in accordance with Section 1106 based on the rainfall rate for which the primary system is sized in Tables 1106.2, 1106.3 and 1106.6. Scuppers shall be sized to prevent the depth of ponding water from exceeding that for which the roof was designed as determined by Section 1101.7. Scuppers shall not have an opening dimension of less than 4 inches (102 mm). The flow through the primary system shall not be considered when sizing the secondary roof drain system.

TABLE 1106.3

SIZE OF HORIZONTAL STORM DRAINAGE PIPING

SIZE OFHORIZONTALPIPING(inches) HORIZONTALLY PROJECTED ROOF AREA (square feet)
Rainfall rate (inches per hour)
1 2 3 4 5 6
1/8 unit vertical in 12 units horizontal (1-percent slope)
3 3,288 1,644 1,096 822 657 548
4 7,520 3,760 2,506 1,800 1,504 1,253
5 13,360 6,680 4,453 3,340 2,672 2,227
6 21,400 10,700 7,133 5,350 4,280 3,566
8 46,000 23,000 15,330 11,500 9,200 7,600
10 82,800 41,400 27,600 20,700 16,580 13,800
12 133,200 66,600 44,400 33,300 26,650 22,200
15 218,000 109,000 72,800 59,500 47,600 39,650
1/4 unit vertical in 12 units horizontal (2-percent slope)
3 4,640 2,320 1,546 1,160 928 773
4 10,600 5,300 3,533 2,650 2,120 1,766
5 18,880 9,440 6,293 4,720 3,776 3,146
6 30,200 15,100 10,066 7,550 6,040 5,033
8 65,200 32,600 21,733 16,300 13,040 10,866
10 116,800 58,400 38,950 29,200 23,350 19,450
12 188,000 94,000 62,600 47,000 37,600 31,350
15 336,000 168,000 112,000 84,000 67,250 56,000
1/2 unit vertical in 12 units horizontal (4-percent slope)
3 6,576 3,288 2,295 1,644 1,310 1,096
4 15,040 7,520 5,010 3,760 3,010 2,500
5 26,720 13,360 8,900 6,680 5,320 4,450
6 42,800 21,400 13,700 10,700 8,580 7,140
8 92,000 46,000 30,650 23,000 18,400 15,320
10 171,600 85,800 55,200 41,400 33,150 27,600
12 266,400 133,200 88,800 66,600 53,200 44,400
15 476,000 238,000 158,800 119,000 95,300 79,250

SECTION 1108

COMBINED SANITARY AND STORM SYSTEM

1108.1 Size of combined drains and sewers. Deleted.

SECTION 1109

VALUES FOR CONTINUOUS FLOW

1109.1 Equivalent roof area. Where there is a continuous or semicontinuous discharge into the building storm drain or building storm sewer, such as from a pump, ejector, air conditioning plant or similar device, each gallon per minute (L/m) of such discharge shall be computed as being equivalent to 96 square feet (9 m2 ) of roof area, based on a rainfall rate of 1 inch ( 25.4 mm) per hour

TABLE 1106.6

SIZE OF SEMICIRCULAR ROOF GUTTERS

DIAMETEROF GUTTERS(inches) HORIZONTALLY PROJECTED ROOF AREA (square feet)
Rainfall rate (inches per hour)
1 2 3 4 5 6
1/16 unit vertical in 12 units horizontal ( 0.5 -percent slope)
3 680 340 226 170 136 113
4 1,440 720 480 360 288 240
5 2,500 1,250 834 625 500 416
6 3,840 1,920 1,280 960 768 640
7 5,520 2,760 1,840 1,380 1,100 918
8 7,960 3,980 2,655 1,990 1,590 1,325
10 14,400 7,200 4,800 3,600 2,880 2,400
1/8 unit vertical 12 units horizontal (1-percent slope)
3 960 480 320 240 192 160
4 2,040 1,020 681 510 408 340
5 3,520 1,760 1,172 880 704 587
6 5,440 2,720 1,815 1,360 1,085 905
7 7,800 3,900 2,600 1,950 1,560 1,300
8 11,200 5,600 3,740 2,800 2,240 1,870
10 20,400 10,200 6,800 5,100 4,080 3,400
1/4 unit vertical in 12 units horizontal (2-percent slope)
3 1,360 680 454 340 272 226
4 2,880 1,440 960 720 576 480
5 5,000 2,500 1,668 1,250 1,000 834
7 11,040 5,520 3,860 2,760 2,205 1,840
8 15,920 7,960 5,310 3,980 3,180 2,655
10 28,800 14,400 9,600 7,200 5,750 4,800
1/2 unit vertical in 12 units horizontal (4-percent slope)
3 1,920 960 640 480 384 320
4 4,080 2,040 1,360 1,020 816 680
5 7,080 3,540 2,360 1,770 1,415 1,180
6 11,080 5,540 3,695 2,770 2,220 1,850
7 15,600 7,800 5,200 3,900 3,120 2,600
8 22,400 11,200 7,460 5,600 4,480 3,730
10 40,000 20,000 13,330 10,000 8,000 6,660

SECTION 1110

CONTROLLED FLOW ROOF DRAIN SYSTEMS

1110.1 General. The roof of a structure shall be designed for the storage of water where the storm drainage system is engineered for controlled flow. The controlled flow roof drain system shall be an engineered system in accordance with this section and the design, submittal, approval, inspection and testing requirements of Sections 106.5, 107, and 108 of the building code and Section 312 of this code. The controlled flow system shall be designed based on the required rainfall rate in accordance with Section 1106.1.

1110.2 Control devices. The control devices shall be installed so that the rate of discharge of water per minute shall not exceed the values for continuous flow as indicated in Section 1109.1.

1110.3 Installation. Runoff control shall be by control devices. Control devices shall be protected by strainers.

1110.4 Minimum number of roof drains. Not less than two roof drains shall be installed in roof areas 10,000 square feet (929 m 2) or less and not less than four 2 roof drains shall be installed in roofs over 10,000 square feet (929 m 2 ) in area.

SECTION 1111

SUBSOIL DRAINS

1111.1 Subsoil drains. Subsoil drains shall be open-jointed, horizontally split or perforated pipe conforming to one of the standards listed in Table 1102.5. Such drains shall not be less than 4 inches (102 mm) in diameter. Where the building is subject to backwater, the subsoil drain shall be protected by an accessibly located backwater valve. Subsoil drains shall discharge to a trapped area drain, sump, dry well or approved location above ground. The subsoil sump shall not be required to have either a gas-tight cover or a vent. The sump and pumping system shall comply with Section 1113.1.

SECTION 1112

BUILDING SUBDRAINS

1112.1 Building subdrains. Building subdrains located below the public sewer level shall discharge into a sump or receiving tank, the contents of which shall be automatically lifted and discharged into the drainage system as required for building sumps. The sump and pumping equipment shall comply with Section 1113.1.

SECTION 1113

SUMPS AND PUMPING SYSTEMS

1113.1 Pumping system. The sump pump, pit and discharge piping shall conform to Sections 1113.1.1 through 1113.1.4.

1113.1.1 Pump capacity and head. The sump pump shall be of a capacity and head appropriate to anticipated use requirements.

1113.1.2 Sump pit. The sump pit shall not be less than 18 inches (457 mm) in diameter and 24 inches (610 mm) deep, unless otherwise approved. The pit shall be accessible and located such that all drainage flows into the pit by gravity. The sump pit shall be constructed of tile, steel, plastic, cast-iron, concrete or other approved material, with a removable cover adequate to support anticipated loads in the area of use. The pit floor shall be solid and provide permanent support for the pump.

1113.1.3 Electrical. Electrical service outlets, when required, shall meet the requirements of NFPA 70.

1113.1.4 Piping. Discharge piping shall meet the requirements of Section 1102.2, 1102.3 or 1102.4 and shall include a full open valve and a full flow check valve. Pipe and fittings shall be the same size as, or larger than, pump discharge tapping.

Exception: In buildings where the "Residential Code of Ohio" applies, only a check valve shall be required, located on the discharge piping from the pump or ejector.

1113.1.5 Water-powered sump pumps. Water-powered sump pumps are only to be used as a secondary back-up pump for the subsoil drainage system and only with appropriate backflow protection in place as required by Section 608.

Replaces: 4101:3-11-01

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: 3/1/98, 1/1/02, 7/1/07