CODES

ADOPTS WITH AMENDMENTS:

International Plumbing Code 2012 (IPC 2012)

Copyright

Preface

Effective Use of the International Plumbing Code

Legislation

Chapter 1 Scope and Administration

Chapter 2 Definitions

Chapter 3 General Regulations

Chapter 4 Fixtures, Faucets and Fixture Fittings

Chapter 5 Water Heaters

Chapter 6 Water Supply and Distribution

Chapter 7 Sanitary Drainage

Chapter 8 Indirect/Special Waste

Chapter 9 Vents

Chapter 10 Traps, Interceptors and Separators

Chapter 11 Storm Drainage

Chapter 12 Special Piping and Storage Systems

Chapter 13 Gray Water Recycling Systems

Chapter 13 Gray Water Recycling Systems

Chapter 14 Referenced Standards

Chapter 15 Rain Water Harvesting Systems

Chapter 16 Reclaimed Water Systems for Buildings

Appendix A Plumbing Permit Fee Schedule

Appendix B Rates of Rainfall for Various Cities

Appendix C Vacuum Drainage System

Appendix D Degree Day and Design Temperatures

Appendix E Sizing of Water Piping System

Appendix F Structural Safety

The provisions of this chapter shall govern the materials, design, construction and installation of storm drainage.
All roofs, paved areas, yards, courts and courtyards shall drain into a separate storm sewer system, or a combined sewer system, or to an approved place of disposal. For one- and two-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.
Storm water shall not be drained into sewers intended for sewage only.
The conductors and the building storm drain shall be tested in accordance with Section 312.
The size of a drainage pipe shall not be reduced in the direction of flow.
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.
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.
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.
Storm drainage systems shall be provided with backwater valves as required for sanitary drainage systems in accordance with Section 715.
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.
Inside storm drainage conductors installed above ground shall conform to one of the standards listed in Table 702.1.
Underground building storm drain pipe shall conform to one of the standards listed in Table 702.2.
Building storm sewer pipe shall conform to one of the standards listed in Table 1102.4.

TABLE 1102.4
BUILDING STORM SEWER PIPE

MATERIALSTANDARD
Acrylonitrile butadiene
styrene (ABS) plastic pipe
ASTM D 2661; ASTM D 2751; ASTM F 628; CSA B181.1;
CSA B182.1
Asbestos-cement pipeASTM C 428
Cast-iron pipeASTM A 74; ASTM A 888;
CISPI 301
Concrete pipe ASTM C 14; ASTM C 76;
CSA A257.1M; CSA A257.2M
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 pipeASTM 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 B182.4;
CSA B181.2; CSA B182.2
Vitrified clay pipeASTM C 4; ASTM C 700
Stainless steel drainage
systems, Type 316L
ASME A112.3.1
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

MATERIALSTANDARD
Asbestos-cement pipe ASTM C 508
Cast-iron pipe ASTM A 74; ASTM A 888;
CISPI 301
Polyethylene (PE) plastic pipe ASTM F 405; CSA B182.1;
CSA B182.6; CSA B182.8
Polyvinyl chloride (PVC)
Plastic pipe (type sewer pipe,
PS25, PS50 or PS100)
ASTM D 2729; ASTM F 891; CSA B182.2; CSA B182.4
Stainless steel drainage systems,
Type 316L
ASME A 112.3.1
Vitrified clay pipeASTM C 4; ASTM C 700
Roof drains shall conform to ASME A112.6.4 or ASME A112.3.1.
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 FITTING

MATERIALSTANDARD
Acrylonitrile butadiene
styrene (ABS) plastic
ASTM D 2661; ASTM D 3311; CSA B181.1
Cast-iron ASME B16.4; ASME B16.12; ASTM A 888; CISPI 301;
ASTM A 74
Coextruded composite ABS
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 IPS-DR,
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 alloyASME B16.15; ASME B16.18; ASME B16.22; ASME B16.23; ASME B16.26; ASME B16.29
Gray iron and ductile ironAWWA C110/A21.10
Malleable ironASME B16.3
Plastic, generalASTM F 409
Polyethylene (PE) plastic pipeASTM F 2306/F 2306M
Polyvinyl chloride (PVC)
plastic
ASTM D 2665; ASTM D 3311; ASTM F 1866
SteelASME B16.9; ASME B16.11; ASME B16.28
Stainless steel drainage
systems, Type 316L
ASME A112.3.1
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.
Storm water traps shall be of the same material as the piping system to which they are attached.
Traps for individual conductors shall be the same size as the horizontal drain to which they are connected.
An accessible cleanout shall be installed on the building side of the trap.
Conductor pipes shall not be used as soil, waste or vent pipes, and soil, waste or vent pipes shall not be used as conductors.
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 in the same horizontal plane through a single-wye fitting to the combined sewer not less than 10 feet (3048 mm) downstream from any soil stack.
Floor drains shall not be connected to a storm drain.
Deleted
Roof drains shall be installed in accordance with the manufacturer’s instructions. The inside opening for the roof drain shall not be obstructed by the roofing membrane material.

Deleted

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.
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.
For SI: 1 inch = 25.4 mm.
Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington D.C.

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.

FIGURE 1106.1—continued
100-YEAR, 1-HOUR RAINFALL (INCHES) CENTRAL UNITED STATES

For SI: 1 inch = 25.4 mm.
Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington D.C.

FIGURE 1106.1—continued
100-YEAR, 1-HOUR RAINFALL (INCHES) WESTERN UNITED STATES

For SI: 1 inch = 25.4 mm.
Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington D.C.

FIGURE 1106.1—continued
100-YEAR, 1-HOUR RAINFALL (INCHES) ALASKA

For SI: 1 inch = 25.4 mm.
Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington D.C.

FIGURE 1106.1—continued
100-YEAR, 1-HOUR RAINFALL (INCHES) HAWAII

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

TABLE 1106.2(1)
SIZE OF CIRCULAR VERTICAL CONDUCTORS AND LEADERS

DIAMETER
OF LEADER
(inches)a
HORIZONTALLY PROJECTED ROOF AREA (square feet)
Rainfall rate (inches per hour)
123456789101112
22,8801,440960720575480410360320290260240
38,8004,4002,9302,2001,7601,4701,2601,100980880800730
418,4009,2006,1304,6003,6803,0702,6302,3002,0451,8401,6751,530
534,60017,30011,5308,6506,9205,7654,9454,3253,8453,4603,1452,880
654,00027,00017,99513,50010,8009,0007,7156,7506,0005,4004,9104,500
8116,00058,00038,66029,00023,20019,31516,57014,50012,89011,60010,5459,600
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

DIMENSIONS OF
COMMON LEADER SIZES
width x length (inches)a, b
HORIZONTALLY PROJECTED ROOF AREA (square feet)
Rainfall rate (inches per hour)
123456789101112
13/4 × 21/23,4101,7001,130850680560480420370340310280
2 × 35,5402,7701,8401,3801,100920790690610550500460
23/4 × 41/412,8306,4104,2703,2002,5602,1301,8301,6001,4201,2801,1601,060
3 × 413,2106,6004,4003,3002,6402,2001,8801,6501,4601,3201,2001,100
31/2 × 415,9007,9505,3003,9703,1802,6502,2701,9801,7601,5901,4401,320
31/2 × 521,31010,6507,1005,3204,2603,5503,0402,6602,3602,1301,9301,770
33/4 × 43/421,96010,9807,3205,4904,3903,6603,1302,7402,4402,1901,9901,830
33/4 × 51/425,52012,7608,5006,3805,1004,2503,6403,1902,8302,5502,3202,120
31/2 × 627,79013,8909,2606,9405,5504,6303,9703,4703,0802,7702,5202,310
4 × 632,98016,49010,9908,2406,5905,4904,7104,1203,6603,2902,9902,740
51/2 × 51/244,30022,15014,76011,0708,8607,3806,3205,5304,9204,4304,0203,690
71/2 × 71/2100,50050,25033,50025,12020,10016,75014,35012,56011,16010,0509,1308,370
For SI: 1 inch = 25.4 mm, 1 square foot = 0.0929 m2.
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.
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 slope of horizontal branches shall be not less than one-eighth unit vertical in 12 units horizontal (1-percent slope) unless otherwise approved.

TABLE 1106.3
SIZE OF HORIZONTAL STORM DRAINGE PIPING

SIZE OF
HORIZONTAL
PIPING
(inches)
HORIZONTALLY PROJECTED ROOF AREA (square feet)
Rainfall rate (inches per hour)
123456
1/8 unit vertical in 12 units horizontal (1-percent slope)
3
4
5
6
8
10
12
15
3,288
7,520
13,360
21,400
46,000
82,800
133,200
218,000
1,644
3,760
6,680
10,700
23,000
41,400
66,600
109,000
1,096
2,506
4,453
7,133
15,330
27,600
44,400
72,800
822
1,800
3,340
5,350
11,500
20,700
33,300
59,500
657
1,504
2,672
4,280
9,200
16,580
26,650
47,600
548
1,253
2,227
3,566
7,600
13,800
22,200
39,650
1/4 unit vertical in 12 units horizontal (2-percent slope)
3
4
5
6
8
10
12
15
4,640
10,600
18,880
30,200
65,200
116,800
188,000
336,000
2,320
5,300
9,440
15,100
32,600
58,400
94,000
168,000
1,546
3,533
6,293
10,066
21,733
38,950
62,600
112,000
1,160
2,650
4,720
7,550
16,300
29,200
47,000
84,000
928
2,120
3,776
6,040
13,040
23,350
37,600
67,250
773
1,766
3,146
5,033
10,866
19,450
31,350
56,000
1/2 unit vertical in 12 units horizontal (4-percent slope)
3
4
5
6
8
10
12
15
6,576
15,040
26,720
42,800
92,000
171,600
266,400
476,000
3,288
7,520
13,360
21,400
46,000
85,800
133,200
238,000
2,295
5,010
8,900
13,700
30,650
55,200
88,800
158,800
1,644
3,760
6,680
10,700
23,000
41,400
66,600
119,000
1,310
3,010
5,320
8,580
18,400
33,150
53,200
95,300
1,096
2,500
4,450
7,140
15,320
27,600
44,400
79,250
For SI: 1 inch = 25.4 mm, 1 square foot = 0.0929 m2.
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.
Parapet wall roof drainage scupper and overflow scupper location shall comply with the requirements of Section 1503.4 of the International Building Code.
The size of semicircular gutters shall be based on the maximum projected roof area in accordance with Table 1106.6.

TABLE 1106.6
SIZE OF SEMICIRCULAR ROOF GUTTERS

DIAMETER OF
GUTTERS
(inches)
HORIZONTALLY PROJECTED ROOF AREA (square feet)
Rainfall rate (inches per hour)
123456
1/16 unit vertical in 12 units horizontal (0.5-percent slope)
3
4
5
6
7
8
10
680
1,440
2,500
3,840
5,520
7,960
14,400
340
720
1,250
1,920
2,760
3,980
7,200
226
480
834
1,280
1,840
2,655
4,800
170
360
625
960
1,380
1,990
3,600
136
288
500
768
1,100
1,590
2,880
113
240
416
640
918
1,325
2,400
1/8 unit vertical 12 units horizontal (1-percent slope)
3
4
5
6
7
8
10
960
2,040
3,520
5,440
7,800
11,200
20,400
480
1,020
1,760
2,720
3,900
5,600
10,200
320
681
1,172
1,815
2,600
3,740
6,800
240
510
880
1,360
1,950
2,800
5,100
192
408
704
1,085
1,560
2,240
4,080
160
340
587
905
1,300
1,870
3,400
1/4 unit vertical in 12 units horizontal (2-percent slope)
3
4
5
6
7
8
10
1,360
2,880
5,000
7,680
11,040
15,920
28,800
680
1,440
2,500
3,840
5,520
7,960
14,400
454
960
1,668
2,560
3,860
5,310
9,600
340
720
1,250
1,920
2,760
3,980
7,200
272
576
1,000
1,536
2,205
3,180
5,750
226
480
834
1,280
1,840
2,655
4,800
1/2 unit vertical in 12 units horizontal (4-percent slope)
3
4
5
6
7
8
10
1,920
4,080
7,080
11,080
15,600
22,400
40,000
960
2,040
3,540
5,540
7,800
11,200
20,000
640
1,360
2,360
3,695
5,200
7,460
13,330
480
1,020
1,770
2,770
3,900
5,600
10,000
384
816
1,415
2,220
3,120
4,480
8,000
320
680
1,180
1,850
2,600
3,730
6,660
For SI: 1 inch = 25.4 mm, 1 square foot = 0.0929 m2.
Siphonic roof drains and drainage systems shall be designed in accordance with ASME A112.6.9 and ASPE 45.
Where roof drains are required, secondary (emergency overflow) 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.
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.
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(1), 1106.2(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 have an opening dimension of not less than 4 inches (102 mm). The flow through the primary system shall not be considered when sizing the secondary roof drain system.
The size of a combination sanitary and storm drain or sewer shall be computed in accordance with the method in Section 1106.3. The fixture units shall be converted into an equivalent projected roof or paved area. Where the total fixture load on the combined drain is less than or equal to 256 fixture units, the equivalent drainage area in horizontal projection shall be taken as 4,000 square feet (372 m2). Where the total fixture load exceeds 256 fixture units, each additional fixture unit shall be considered the equivalent of 15.6 square feet (1.5 m2) of drainage area. These values are based on a rainfall rate of 1 inch (25 mm) per hour.
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.
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 Section 316.1. The controlled flow system shall be designed based on the required rainfall rate in accordance with Section 1106.1.
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 1110.1.
Runoff control shall be by control devices. Control devices shall be protected by strainers.
Not less than two roof drains shall be installed in roof areas 10,000 square feet (929 m2) or less and not less than four roof drains shall be installed in roofs over 10,000 square feet (929 m2) in area.
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 1114.1.
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 1114.1.
The sump pump, pit and discharge piping shall conform to Sections 1114.1.1 through 1114.1.4.
The sump pump shall be of a capacity and head appropriate to anticipated use requirements.
The sump pit shall not be less than 18 inches (457 mm) in diameter and not less than 24 inches (610 mm) in depth, 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.
Electrical service outlets, when required, shall meet the requirements of NFPA 70.
Discharge piping shall meet the requirements of Section 1102.2, 1102.3 or 1102.4 and shall include a gate valve and a full flow check valve. Pipe and fittings shall be the same size as, or larger than, pump discharge tapping.

Exception: In one- and two-family dwellings, only a check valve shall be required, located on the discharge piping from the pump or ejector.

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