CODES

ADOPTS WITH AMENDMENTS:

International Plumbing Code 2009 (IPC 2009)

Copyright

Preface

Effective Use of the International Plumbing Code

Ordinance

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 Referenced Standards

Appendix A Plumbing Permit Fee Schedule

Appendix B Rates of Rainfall for Various Cities

Appendix C Gray Water Recycling Systems

Appendix D Degree Day and Design Temperatures

Appendix E Sizing of Water Piping System

Appendix F Structural Safety

Appendix G Vacuum Drainage System

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

MATERIAL

STANDARD

Acrylonitrile butadiene styrene (ABS) plastic pipe

ASTM D 2661; ASTM D 2751; ASTM F 628; CAN/CSA B181.1;
CAN/CSA B182.1

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 A257.1M;
CAN/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 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 B182.4;
CSA B181.2; CSA B182.2

Vitrified clay pipe

ASTM 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

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 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;
CAN/CSA B182.4

Stainless steel drainage systems, Type 316L

ASME A 112.3.1

Vitrified clay pipe

ASTM C 4; ASTM C 700

Roof drains shall conform to ASME A112.21.2M 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 FITTINGS

MATERIAL

STANDARD

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 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 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 alloy

ASME B16.15; ASME B16.18; ASME B16.22; ASME B16.23; ASME B16.26; ASME B16.29

Gray iron and ductile iron

AWWA C110

Malleable iron

ASME B16.3

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 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 at least 10 feet (3048 mm) downstream from any soil stack.
Floor drains shall not be connected to a storm drain.
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.
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.
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 Tables 1106.2(1) and 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)

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

DIMENSIONS OF COMMON LEADER SIZES width 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

13/4 × 21/2

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

23/4 × 41/4

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

31/2 × 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

31/2 × 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

33/4 × 43/4

21,960

10,980

7,320

5,490

4,390

3,660

3,130

2,740

2,440

2,190

1,990

1,830

33/4 × 51/4

25,520

12,760

8,500

6,380

5,100

4,250

3,640

3,190

2,830

2,550

2,320

2,120

31/2 × 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

51/2 × 51/2

44,300

22,150

14,760

11,070

8,860

7,380

6,320

5,530

4,920

4,430

4,020

3,690

71/2 × 71/2

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.

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.

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)

1

2

3

4

5

6

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 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)

1

2

3

4

5

6

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.

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.
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, 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.
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 105.4. 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 1109.1.
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 1113.1.
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 1113.1.
The sump pump, pit and discharge piping shall conform to Sections 1113.1.1 through 1113.1.4.
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 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.
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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