CPC · California Plumbing Code

Trap materials, sizes, and self‑cleaning requirements

Q: Can a mechanical check valve be used instead of a trap?

No. Bladders, check valves or other movable‑part devices are prohibited as traps by § 1004.2 . Use an approved liquid‑seal trap made of approved materials instead.

Q: What depth should I set the trap seal to?

Set the liquid seal to at least 2 inches and not more than 4 inches , unless the AHJ requires a deeper seal — see § 1005.1 .

Q: Are plastic traps allowed?

Yes — ABS and PVC (among others) are listed as acceptable trap materials in § 1003.1 so long as the design is standard and self‑cleaning.

Q: My floor drain is rarely used — do I need anything special?

Floor drains subject to infrequent use should be protected with a trap seal primer (accessible for maintenance) unless the AHJ deems it unnecessary; primer devices have referenced standards in § 1007.1–1007.2 .

Q: Where do I find minimum trap diameters for each fixture?

Minimum trap sizes and trap‑arm sizes by fixture are listed in Table 702.1 (and Table 702.1(1)) of the CPC. Consult that table for fixture‑specific minimums.

Traps must be **self‑cleaning**, made of approved materials (ABS, PVC, cast‑brass, etc.), must not rely on **movable parts**, and must provide a liquid seal between **2 in. and 4 in.** unless the authority having jurisdiction requires otherwise (see **§ 1003.1**, **§ 1004.2**, **§ 1005.1**).

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Last reviewed: July 6, 2026

What the code requires — plain English

Traps must be self‑cleaning and made of approved materials (for example ABS, cast‑brass, cast‑iron, lead, PP, PVC or other approved material) — see § 1003.1.
Devices that rely on movable parts (bladders, check valves, etc.) are prohibited from serving as traps — see § 1004.2.
Each fixture trap must provide a liquid trap seal of not less than 2 inches and not more than 4 inches (unless the AHJ requires a deeper seal) — see § 1005.1.

The single most important requirement: every trap (except those inside interceptors) must be self‑cleaning, made of an approved material, and have a liquid seal between 2 in. and 4 in. — § 1003.1, § 1004.2, § 1005.1.

Requirements in detail

Materials and construction (what you may use)

Approved materials listed for typical fixture traps include ABS, cast‑brass, cast‑iron, lead, polypropylene (PP), PVC, or other approved materials. Exposed/copper‑alloy tubing traps are permitted where specifically limited (minimum 17 B & S gauge) — see § 1003.1.
Defined term: Self‑cleaning (as used in the chapter) means the trap has no interior partitions and is of a design that the normal flow tends to scour solids and prevent accumulation — this is required by § 1003.1.
Design/weight: traps for bathtubs, showers, lavatories, sinks, laundry sinks, floor drains, urinals, drinking fountains, dental units and similar fixtures shall be of standard design and weight (see § 1003.1).

Prohibited trap types

No movable‑part traps. The code explicitly prohibits using bladders, check valves, or other devices with movable parts to function as the trap (they can fail and allow sewer gas or siphon the seal) — § 1004.2.

Trap seal depth (critical thresholds)

Minimum trap seal: 2 inches (51 mm).
Maximum trap seal: 4 inches (102 mm), unless a deeper seal is specifically required by the Authority Having Jurisdiction (AHJ). See § 1005.1.

Decision‑relevant table (quick reference)

Topic	Decision value(s)	Code Reference
Required to be self‑cleaning (except traps inside interceptors)	Yes — self‑cleaning	§ 1003.1
Allowed trap materials (typical list)	ABS, cast‑brass, cast‑iron, lead, PP, PVC, or other approved material; exposed copper‑alloy tubing ≥ 17 B&S gauge allowed in specific cases	§ 1003.1
Prohibited devices as traps	Bladders, check valves, movable parts — not permitted to serve as traps	§ 1004.2
Trap seal depth (liquid seal)	≥ 2 in. and ≤ 4 in. (deeper only if AHJ requires)	§ 1005.1
Tailpiece maximum vertical distance (related fit/installation)	Tailpiece shall not exceed 24 in. (610 mm)	§ 1001.2
Minimum trap size guidance (fixture‑specific)	See Table 702.1 for minimum trap & trap arm sizes by fixture (e.g., lavatory 1¼ or 1½ in., floor drain 2 in., water closet 3 in.)	Table 702.1 (see Table 702.1 / Table 702.1(1))

Notes on the table: the trap seal depth and movable parts prohibition are taken directly from the chapter sections identified above; minimum trap diameters and fixture sizing come from Table 702.1 (referenced in the CPC). If you need a specific fixture‑by‑fixture minimum, consult Table 702.1 in the CPC.

Exceptions & special cases

Traps located within interceptors or similar separating devices are excepted from the standalone self‑cleaning requirement in § 1003.1 (the interceptor itself has other design/cleaning requirements).
The AHJ may require a deeper trap seal than 4 inches where necessary (for example, heavy odor control or specific process needs) — see § 1005.1.
Exposed copper‑alloy tubing traps are permitted only when readily accessible and meet the minimum gauge (17 B & S, 0.045 in.) — see § 1003.1.

Common mistakes

Installing a device that uses movable parts (air bladder, spring check) and calling it a trap — this is explicitly prohibited by § 1004.2. Inspectors commonly see "trap inserts" with moving pieces; these cannot serve as the trap.
Using non‑approved materials or thin, under‑gauged exposed tubing where code requires a minimum gauge (e.g., copper tubing < 17 B & S). Verify the material and gauge against § 1003.1.
Setting traps with less than 2 in. of liquid seal (risk of sewer gas) or much deeper than 4 in. without AHJ approval — check § 1005.1.
Long tailpieces or remote connections that prevent the trap from self‑scouring: tailpieces should be as short as practical and in no case exceed 24 in. (see § 1001.2).

Worked example

Scenario: You are specifying a trap for a new lavatory in a commercial tenant space.

Material: choose an ABS trap (an approved material for lavatories). This complies with § 1003.1.
Size: consult Table 702.1 — a lavatory typically uses a 1¼ in. or 1½ in. trap depending on the fixture rating; pick the manufacturer‑recommended 1¼ in. trap if the lavatory and DFU permit. (See Table 702.1.)
Trap seal: set the trap so the liquid seal is between 2 in. and 4 in.; confirm the vertical depth at the trap weir is within that range — this follows § 1005.1.
Movable parts: do not spec any cartridge/bladder style trap devices — they are prohibited by § 1004.2.
Tailpiece: keep the tailpiece short and under 24 in. to ensure proper function and self‑scouring per § 1001.2.

Result: an ABS 1¼‑inch trap, installed with a 2–4 in. trap seal, short tailpiece, no movable parts — compliant with § 1003.1, § 1004.2, § 1005.1.

Related provisions (CPC sections you should also check)

§ 1003.1 — Traps — General requirements (materials, self‑cleaning).
§ 1004.2 — Movable parts prohibited (bladders/checks) for traps.
§ 1005.1 — Trap seal depth (2–4 in.); AHJ may require deeper.
§ 1001.2 — Limit on tailpiece length (max 24 in.); fixture connection rules.
Table 702.1 / Table 702.1(1) — Minimum trap and trap‑arm sizes and DFU values by fixture.
§ 1007.1 / § 1007.2 — Trap seal primers (when floor traps are infrequently used; primer device standards).
§ 1009.1 – 1009.7 / Table 1009.1 — Interceptors/clarifiers (when traps are inside interceptors or deep‑seal floor drains).

If you need: I can pull the exact lines from Table 702.1 for a specific fixture, or create installation‑checklists that map each item to the precise code text.

Code references

Grounded in the retrieved California Plumbing Code — click a citation to read the verbatim passage:

CPC § 1.859 High relevance — show source text

78|–|1.859|0.463| |35.31|–|2.247|0.559| |38.84|–|2.667|0.663| |42.37|–|3.121|0.775| |45.90|–|3.607|0.895| |49.43|–|4.125|1.022| |52.97|–|–|1.157| |56.50|–|–|1.299| |60.03|–|–|1.449| |63.56|–|–|1.607| |67.09|–|–|1.772| |70.62|–|–|1.944| |81.21|–|–|2.503| |91.81|–|–|3.127| |102.40|–|–|3.813|

For SI units: 1 standard cubic foot per minute = 28.32 SLPM, 1 inch = 25 mm, 1 foot = 304.8 mm, 1 pound-force per square inch = 6.8947 kPa

Notes: 1 Based on pressure of 14.7 psig (101 kPa) at 68°F (20°C). 2 Based on pressure of 55 psig (379 kPa) at 68°F (20 °C).

2025 CALIFORNIA PLUMBING CODE 291

HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICAL VACUUM SYSTEMS

TABLE 1323.1.4(5) PRESSURE LOSS FOR VACUUM (continued)

FLOW RATE (SCFM)1	VACUUM LOSS (inch of mercury) PER 100 FEET FOR COPPER TUBE2	Col3	Col4	Col5	Col6
FLOW RATE (SCFM)1	3⁄4 INCH TUBE	1 INCH TUBE	11⁄4 INCH TUBE	11⁄2 INCH TUBE	2 INCH TUBE
49.43	–	–	–	3.645	0.956
52.97	–	–	–	4.122	1.081
56.50	–	–	–	4.626	1.212
63.56	–	–	–	–	1.495
70.62	–	–	–	–	1.803
77.68	–	–	–	–	2.138
84.74	–	–	–	–	2.497
91.81	–	–	–	–	2.882
98.87	–	–	–	–	3.291
105.93	–	–	–	–	3.724
112.99	–	–	–	–	4.181

CPC § 1.6 Medium relevance — show source text

PLUMBING APPLIANCES, APPURTENANCES, OR FIXTURES	MINIMUM SIZE TRAP AND TRAP ARM7 (inches)	PRIVATE	PUBLIC	ASSEMBLY8
Water Closet, greater than 1.6 GPF Gravity Tank6	3	4.0	6.0	8.0
Water Closet, greater than 1.6 GPF Flushometer Valve6	3	4.0	6.0	8.0

For SI units: 1 inch = 25 mm

Notes: 1 Indirect waste receptors shall be sized based on the total drainage capacity of the fixtures that drain thereinto, in accordance with Table 702.2. 2 Provide a 2 inch (50 mm) minimum drain. 3 For refrigerators, coffee urns, water stations, and similar low demands. 4 For commercial sinks, dishwashers, and similar moderate or heavy demands. 5 Buildings having a clothes-washing area with clothes washers in a battery of three or more clothes washers shall be rated at 6 fixture units each for purposes of sizing common horizontal and vertical drainage piping. 6 Water closets shall be computed as 6 fixture units where determining septic tank sizes based on Appendix H of this code. 7 Trap sizes shall not be increased to the point where the fixture discharge is capable of being inadequate to maintain their self-scouring properties. 8 Assembly [Public Use (see Table 422.1)]. 9 For a bathtub to shower retrofit, a 1 1 / 2 inch (40 mm) trap and trap arm shall be permitted with a maximum shower size of 36 inches (914 mm) in width and 60 inches (1524 mm) in length. See Section 408.6 and Section 408.7. 10 For drainage fixture unit values related to lots within mobilehome parks in all parts of the State of California, see California Code of Regulations, Title 25, Division 1, Chapter 2, Article 5, Section 1268. For drainage fixture unit values related to lots within special occupancy parks in all parts of the State of Cal- ifornia, see California Code of Regulations, Title 25, Division 1, Chapter 2.2, Article 5, Section 2268.

required, and the unit equivalent of fixtures and devices not shown in Table 702.1 shall be based on the size of trap or trap

arm.

Maximum drainage fixture units for a fixture trap and trap arm loadings for sizes up to 4 inches (100 mm) shall be in accordance with Table 702.1(1).

TABLE 702.1(1) MAXIMUM DRAINAGE FIXTURE UNITS FOR A

TRAP AND TRAP ARM*

SIZE OF TRAP AND TRAP ARM (inches)	DRAINAGE FIXTURE UNIT VALUES (DFU)
11⁄4	1 unit
11⁄2	3 units
2	4 units
3	6 units
4	8 units

For SI Units: 1 inch = 25 mm

*** Exception:** On self-service laundries.

702.2 Intermittent Flow. Drainage fixture units for intermittent flow into the drainage system shall be computed on the rated discharge capacity in gallons per minute (gpm) (L/s) in accordance with Table 702.2.

TABLE 702.1(1) MAXIMUM DRAINAGE FIXTURE UNITS FOR A

TRAP AND TRAP ARM*

CPC § 9-3 Medium relevance — show source text
902 Special Use and Occupancy. . . . . . . . . . . . . . . . . . . . . . 9-3

903 Building Elements and Materials . . . . . . . . . . . . . . . . . 9-3

904 Fire Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4

905 Means of Egress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4

906 Structural. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4

907 Energy Conservation. . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4

908 Emergency Responder Communications Enhancement System Coverage. . . . . . . . . . . . . . . . 9-5

CHAPTER 10 CHANGE OF OCCUPANCY . . . . . . . . . . . . . . .10-3

1001 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3

1002 Special Use and Occupancy. . . . . . . . . . . . . . . . . . . . . 10-3

1003 Building Elements and Materials . . . . . . . . . . . . . . . . 10-3

1004 Fire Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3

1005 Means of Egress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3

1006 Structural. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3

1007 Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4

1008 Mechanical. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4

1009 Plumbing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4

1010 Other Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5

1011 Change of Occupancy Classification . . . . . . . . . . . . . 10-5

CHAPTER 11 ADDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . .11-3
CPC § 10-3 Medium relevance — show source text
1003 Building Elements and Materials . . . . . . . . . . . . . . . . 10-3

1004 Fire Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3

1005 Means of Egress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3

1006 Structural. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3

1007 Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4

1008 Mechanical. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4

1009 Plumbing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4

1010 Other Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5

1011 Change of Occupancy Classification . . . . . . . . . . . . . 10-5

CHAPTER 11 ADDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . .11-3

1101 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3

1102 Heights and Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3

1103 Structural. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4

1104 Energy Conservation. . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4

CHAPTER 12 HISTORIC BUILDINGS . . . . . . . . . . . . . . . . . .12-1

xviii 2025 CALIFORNIA EXISTING BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

CHAPTER 13 PERFORMANCE COMPLIANCE METHODS. . 13-3

1301 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-3

1302 Applicability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-3

1303 Acceptance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-4
CPC § 101.5 Medium relevance — show source text
B 101.5 Trap Sizes. Trap sizes are required to be equivalent to the branches they serve (two pipe sizes larger than normal), and tailpieces between fixtures or floor drains and such traps shall be reduced to normal size.

B 101.6 Layout Drawings. Duplicate layout drawings of each such proposed piping system shall be presented to the Authority Having Jurisdiction and approval obtained before an installation is made. Complicated layouts shall be checked by qualified personnel. B 101.6.1 Example of Sizing. A floor drain normally requires a 2 inch (50 mm) trap and waste. On a combination waste and vent system, both trap and waste shall be increased two pipe sizes (through 2 [1] ⁄ 2 inches and 3 inches) (65 mm and 80 mm), which would make the trap 3 inches (80 mm). Pipe sizes recognized for this purpose are 2 inches, 2 [1] ⁄ 2 inches, 3 inches, 3 [1] ⁄ 2 inches, 4 inches, 4 [1] ⁄ 2 inches, 5 inches, 6 inches, etc. (50 mm, 65 mm, 80 mm, 90 mm, 100 mm, 115 mm, 125 mm, 150 mm, etc.). The tailpiece between the floor drain and its trap shall be 2 inches (50 mm) (or normal size) to ensure that the amount of wastewater entering the trap partially fills the waste branch. A 3 inch (80 mm) floor drain would thus require a 4 inch (100 mm) trap, and a 4 inch (100 mm) floor drain would require a 5 inch (125 mm) trap for the reasons previously stated.

WHERE IN DOUBT, CHECK WITH YOUR LOCAL Authority Having Jurisdiction.

2025 CALIFORNIA PLUMBING CODE 383

), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

384 2025 CALIFORNIA PLUMBING CODE

), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

CALIFORNIA PLUMBING CODE – MATRIX ADOPTION TABLE

APPENDIX C - ALTERNATE PLUMBING SYSTEMS

(Matrix Adoption Tables are non-regulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)

CPC § 1.11.0. Medium relevance — show source text

Pipe sizes recognized for this purpose are 2 inches, 2 [1] ⁄ 2 inches, 3 inches, 3 [1] ⁄ 2 inches, 4 inches, 4 [1] ⁄ 2 inches, 5 inches, 6 inches, etc. (50 mm, 65 mm, 80 mm, 90 mm, 100 mm, 115 mm, 125 mm, 150 mm, etc.). The tailpiece between the floor drain and its trap shall be 2 inches (50 mm) (or normal size) to ensure that the amount of wastewater entering the trap partially fills the waste branch. A 3 inch (80 mm) floor drain would thus require a 4 inch (100 mm) trap, and a 4 inch (100 mm) floor drain would require a 5 inch (125 mm) trap for the reasons previously stated.

WHERE IN DOUBT, CHECK WITH YOUR LOCAL Authority Having Jurisdiction.

2025 CALIFORNIA PLUMBING CODE 383

384 2025 CALIFORNIA PLUMBING CODE

CALIFORNIA PLUMBING CODE – MATRIX ADOPTION TABLE

APPENDIX C - ALTERNATE PLUMBING SYSTEMS

(Matrix Adoption Tables are non-regulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)

Adopting Agency	BSC	BSC- CG	SFM	HCD	Col6	Col7	DSA	Col9	Col10	OSHPD	Col12	Col13	Col14	Col15	Col16	Col17	BSCC	DPH	AGR	DWR	CEC	CA	SL	SLC
Adopting Agency	BSC	BSC- CG	SFM	1	2	1-AC	AC	SS	SS/CC	1	1R	2	3	4	5	6	6	6	6	6	6	6	6	6
Adopt Entire Chapter
Adopt Entire Chapter as amended (amended sections listed below)
Adopt only those sections that are listed below
Chapter/Section

This state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.0.

2025 CALIFORNIA PLUMBING CODE 385

CPC § 101.3 Medium relevance — show source text
Combination waste and vent systems are intended primarily for extensive floor or shower drain installations where separate venting is not practical, for floor sinks in markets, demonstration or work tables in school buildings, or for similar applications where the fixtures are not adjacent to walls or partitions. Due to its oversize characteristics, such a waste system is not self-scouring and, consequently, care shall be exercised as to the type of fixtures connected to it and the location of cleanouts. Given its grease-producing potential, restaurant kitchen equipment shall not be connected to a combination waste and vent system.

B 101.3 Caution. Caution shall be exercised to exclude appurtenances delivering large quantities or surges of water (such as pumps, sand interceptors, etc.) from combination waste and vent systems so that adequate venting will be maintained. Small fixtures with a waste-producing potential of less than 7 [1] ⁄ 2 gallons per minute (gpm) (0.47 L/s) shall be permitted to be safely assigned a loading value of one unit. Long runs shall be laid at the minimum permissible slope to keep tailpieces as short as possible. Tailpieces shall not exceed 2 feet (610 mm) in length, which shall necessitate slopes up to 45 degrees (0.79 rad) (see definition of horizontal pipe) on some branches.

B 101.4 Pneumatics. It is essential that the pneumatics of such a system be properly engineered, as the air pressure within the line shall at all times balance that of outside atmosphere to prevent either trap seal loss or air locking between traps. Long mains shall be provided with additional relief vents located at intervals not exceeding 100 feet (30 480 mm). Each such relief vent shall equal not less than one-half of the inside cross-sectional area of the drainpipe served.

B 101.5 Trap Sizes. Trap sizes are required to be equivalent to the branches they serve (two pipe sizes larger than normal), and tailpieces between fixtures or floor drains and such traps shall be reduced to normal size.

B 101.6 Layout Drawings. Duplicate layout drawings of each such proposed piping system shall be presented to the Authority Having Jurisdiction and approval obtained before an installation is made. Complicated layouts shall be checked by qualified personnel. B 101.6.1 Example of Sizing. A floor drain normally requires a 2 inch (50 mm) trap and waste. On a combination waste and vent system, both trap and waste shall be increased two pipe sizes (through 2 [1] ⁄ 2 inches and 3 inches) (65 mm and 80 mm), which would make the trap 3 inches (80 mm). Pipe sizes recognized for this purpose are 2 inches, 2 [1] ⁄ 2 inches, 3 inches, 3 [1] ⁄ 2 inches, 4 inches, 4 [1] ⁄ 2 inches, 5 inches, 6 inches, etc. (50 mm, 65 mm, 80 mm, 90 mm, 100 mm, 115 mm, 125 mm, 150 mm, etc.). The tailpiece between the floor drain and its trap shall be 2 inches (50 mm) (or normal size) to ensure that the amount of wastewater entering the trap partially fills the waste branch.
CPC § 10-5 Medium relevance — show source text
1002 Maintenance and Plans . . . . . . . . . . . . . . . . . . . . . . . . 10-5

1003 General Means of Egress . . . . . . . . . . . . . . . . . . . . . . . 10-5

1004 Occupant Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-7

1005 Means of Egress Sizing. . . . . . . . . . . . . . . . . . . . . . . . . 10-9

1006 Number of Exits and Exit Access Doorways . . . . . 10-10

1007 Exit and Exit Access Doorway Configuration . . . . 10-14

1008 Means of Egress Illumination . . . . . . . . . . . . . . . . . . 10-14

1009 Accessible Means of Egress. . . . . . . . . . . . . . . . . . . . 10-15

1010 Doors, Gates and Turnstiles . . . . . . . . . . . . . . . . . . . 10-19

1011 Stairways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-29

1012 Ramps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-33

1013 Exit Signs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-34

1014 Handrails. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-36

1015 Guards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-37

1016 Exit Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-39

1017 Exit Access Travel Distance. . . . . . . . . . . . . . . . . . . . 10-40

1018 Aisles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-41

1019 Exit Access Stairways and Ramps . . . . . . . . . . . . . . 10-42

1020 Corridors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-42

1021 Egress Balconies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-44

1022 Exits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-44
CPC § 104.1 Medium relevance — show source text
[A] 104.1 General. The building official is hereby authorized and directed to enforce the provisions of this code.

[A] 104.2 Determination of compliance. The building official shall have the authority to determine compliance with this code, to render interpretations of this code and to adopt policies and procedures in order to clarify the application of its provisions. Such interpretations, policies and procedures:
1. Shall be in compliance with the intent and purpose of this code.
2. Shall not have the effect of waiving requirements specifically provided for in this code.
[A] 104.2.1 Listed compliance. Where this code or a referenced standard requires equipment, materials, products or services to be listed and a listing standard is specified, the listing shall be based on the specified standard. Where a listing standard is not specified, the listing shall be based on an approved listing criteria. Listings shall be germane to the provision requiring the listing. Installation shall be in accordance with the listing and the manufacturer’s instructions, and where required to verify compliance, the listing standard and manufacturer’s instructions shall be made available to the building official.

[A] 104.2.2 Technical assistance. To determine compliance with this code, the building official is authorized to determine compliance with this code, to require the owner or owner’s authorized agent to provide a technical opinion and report.

[A] 104.2.2.1 Cost. A technical opinion and report shall be provided without charge to the jurisdiction.

[A] 104.2.2.2 Preparer qualifications. The technical opinion and report shall be prepared by a qualified engineer, specialist, laboratory or specialty organization acceptable to the building official. The building official is authorized to require design submittals to be prepared by, and bear the stamp of, a registered design professional.

[A] 104.2.2.3 Content. The technical opinion and report shall analyze the properties of the design, operation or use of the building or premises and the facilities and appurtenances situated thereon to identify and propose necessary recommendations.

[A] 104.2.2.4 Tests. Where there is insufficient evidence of compliance with the provisions of this code, the building official shall have the authority to require tests as evidence of compliance. Test methods shall be as specified in this code or by other recognized test standards. In the absence of recognized test standards, the building official shall approve the testing procedures. Such tests shall be performed by a party acceptable to the building official.

[A] 104.2.3 Alternative materials, design and methods of construction and equipment. The provisions of this code are not intended to prevent the installation of any material or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been approved.

Exception: Performance-based alternative materials, designs or methods of construction and equipment complying with the International Code Council Performance Code . This exception shall not apply to alternative structural materials or to alternative structural designs. [DSA-SS, DSA-SS/CC] The International Code Council Performance Code is not permitted by DSA.

[DSA-SS, DSA-SS/CC & OSHPD 1, 1R, 2, 4 & 5] Alternative system shall satisfy ASCE 7 Section 1.3, unless more restrictive require- ments are established by this code for an equivalent system.

[DSA-SS, DSA-SS/CC] Alternative systems shall also satisfy the California Administrative Code, Section 4-304.
CPC § 1603.4 Medium relevance — show source text
locking devices,
and verify operation.|After initial installation and
every 12 months thereafter| |

Inspect caution labels and
marking.|After initial installation and
every 12 months thereafter| |

Cross-connection inspection
and test.*|After initial installation and
every 12 months thereafter| |

Test water quality of rainwater
catchment systems required by
Section 1603.4 to maintain a
minimum water quality.|Every 12 months. After system
renovation or repair.|
- The cross-connection test shall be performed in the presence of the Authority Having Jurisdiction in accordance with the requirements of this chapter.
1601.5.1 Maintenance Responsibility. The required maintenance and inspection of rainwater catchment systems shall be the responsibility of the property owner unless otherwise required by the Authority Having Jurisdiction.

2025 CALIFORNIA PLUMBING CODE 327

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NONPOTABLE RAINWATER CATCHMENT SYSTEMS

1601.6 Operation and Maintenance Manual. An operation and maintenance manual for rainwater catchment systems required to have a permit in accordance with Section 1601.3, shall be supplied to the building owner by the system designer or installer . The operating and maintenance manual shall include the following:

(1) Diagram(s) of the entire system and the location of system components.

(2) Instructions for operating and maintaining the system.

(3) Instructions on maintaining the required water quality as for rainwater catchment systems .

(4) Details startup, shutdown, and deactivating the system for maintenance, repair, or other purposes.

(5) Applicable testing, inspection, and maintenance frequencies in accordance with Section 1601.5.

(6) A method of contacting the installer and/or manufacturer(s).

(7) Directions to the owner or occupant that the manual shall remain with the building throughout the life cycle of the structure.

1601.7 Minimum Water Quality Requirements. The minimum water quality for rainwater catchment systems shall comply with the applicable water quality requirements for the intended application as determined by the Authority Having Jurisdiction. Water quality for nonpotable rainwater catchment systems shall comply with Section 1603.4. In the absence of water quality requirements for harvested rainwa- ter, Table 1603.4 shall apply.

Exceptions:

(1) Water treatment is not required for rainwater catchment systems used for aboveground irrigation with a maximum storage capacity of 360 gallons (1363 L).

(2) Water treatment is not required for rainwater catchment systems used for surface, subsurface or drip irrigation. 1601.8 Material Compatibility. Rainwater catchment systems shall be constructed of materials that are compatible with the type of pipe and fitting materials, water treatment, and water conditions in the system. 1601.9 System Controls. Controls for pumps, valves, and other devices that contain mercury that come in contact with rainwater supply shall not be permitted. 1601.10 Separation Requirements. Underground rainwater catchment service piping shall be separated from the building sewer in accordance with Section 609.2.
CPC § 9-53 Medium relevance — show source text
911 Fire Command Center. . . . . . . . . . . . . . . . . . . . . . . . . . 9-53

912 Fire Department Connections. . . . . . . . . . . . . . . . . . . 9-54

913 Fire Pumps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-55

914 Emergency Responder Safety Features . . . . . . . . . . 9-56

915 Carbon Monoxide (CO) Detection. . . . . . . . . . . . . . . . 9-56

xxii 2025 CALIFORNIA BUILDING CODE

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916 Gas Detection Systems . . . . . . . . . . . . . . . . . . . . . . . . 9-58

917 Mass Notification Systems . . . . . . . . . . . . . . . . . . . . . 9-59

918 Emergency Responder Communication Coverage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-59

CHAPTER 10 MEANS OF EGRESS . . . . . . . . . . . . . . . . . . . . 10-1

1001 Administration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5

1002 Maintenance and Plans . . . . . . . . . . . . . . . . . . . . . . . . 10-5

1003 General Means of Egress . . . . . . . . . . . . . . . . . . . . . . . 10-5

1004 Occupant Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-7

1005 Means of Egress Sizing. . . . . . . . . . . . . . . . . . . . . . . . . 10-9

1006 Number of Exits and Exit Access Doorways . . . . . 10-10

1007 Exit and Exit Access Doorway Configuration . . . . 10-14

1008 Means of Egress Illumination . . . . . . . . . . . . . . . . . . 10-14

1009 Accessible Means of Egress. . . . . . . . . . . . . . . . . . . . 10-15

1010 Doors, Gates and Turnstiles . . . . . . . . . . . . . . . . . . . 10-19

1011 Stairways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-29

1012 Ramps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-33
CPC § 2025 Medium relevance — show source text
The waste must be treated to prevent any damage to the piping or sewage treatment process. Waste receptors are sized and designed to prevent splashing and allow for peak discharge conditions.

Chapter 9 Vents.

Chapter 9 regulates the material, design, and installation of vents. A vent system is a pipe or pipes installed in a drainage system that provide a flow of air to and from the system to ventilate it, provide a circulation of air to eliminate trap siphonage, and reduce back-pressure and vacuum surge. In addition, vents provide the rapid and silent flow of waste without exposing occupants of the building to any sewer gases. Proper installation of vents is crucial, as a telltale sign that there is a problem in the drain and vent system is related to the elevation of the horizontal portion of the venting. Venting is not limited to sanitary drainage systems. Venting methods are applicable to other drainage systems such as those for chemical waste, graywater waste, and clear water waste. Sizing the venting system is directly tied to the design of the drainage system. For example, the velocities in the drainage system and its peak flow rates affect the diameters in the venting system. Where the vertical distance between a fixture outlet and trap is excessive, velocities in the entire drainage system will be greater than those in the vent sizing table. All venting methods in this chapter are categorized as either dry vents or wet vents. Vent stacks, stack vents, branch vents, island vents, relief vents, and individual vents are dry vents. Wet vents (horizontal or vertical), circuit vents, combination drain and vents are versions of “wet venting” in which the vent is wetted by drainage flow.

2025 CALIFORNIA PLUMBING CODE xv

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FORMAT OF THE UNIFORM PLUMBING CODE

Chapter 10 Traps and Interceptors.

Chapter 10 regulates the material, design, and installation of traps, interceptors, and separators. Traps are required on drainage type plumbing fixtures and must be self-scouring without interior partitions. Interceptors, on the other hand, are designed to control what goes down a drain. Interceptors are used to keep harmful substances from entering the sanitary drainage system, such as grease, sand, oil and other materials. The retained materials need periodic removal to maintain efficiency and function of the separating device. The capacity of an interceptor is based on retention and flow rate. There are many types of interceptors that are used at beauty salons, hospitals, meat, fish or foul packaging, refineries, repair garages, gas stations, car washing facilities, various plants, factories, and processing sites. The designer of the building is responsible for locating interceptors with the expectation for the frequency of maintenance, ease of cleaning and floor space for equipment.

Chapter 11 Storm Drainage.

Chapter 11 regulates the removal of stormwater from roofs, yards, paved areas, and similar areas. The objective of storm drainage systems is to provide a conduit or channel through which runoff will be carried from a point of collection to a point of disposal; this protects the property and the public from the uncontrolled flow of runoff and ensures that drains and inlets are adequately sized to receive the volume of runoff that flows to the drains. For the purpose of system design, it’s necessary to specify the duration of a selected storm.
CPC § 1001.0 High relevance — show source text
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CHAPTER 10

TRAPS AND INTERCEPTORS

1001.0 General.

1001.1 Applicability. This chapter shall govern the materials, design, and installation of traps and interceptors.

1001.2 Where Required. Each plumbing fixture shall be separately trapped by an approved type of liquid seal trap. This section shall not apply to fixtures with integral traps. Not more than one trap shall be permitted on a trap arm. Food waste disposers installed with a set of restaurant, commercial, or industrial sinks shall be connected to a separate trap.

Each domestic clothes washer and each laundry sink shall be connected to a separate and independent trap, except that a trap serving a laundry sink shall also be permitted to receive the waste from a clothes washer set adjacent to it.

The vertical distance between a fixture outlet and the trap weir shall be as short as practicable, but in no case shall the tailpiece exceed 24 inches (610 mm) in length.

One trap shall be permitted to serve a set of not more than three single compartment sinks or laundry sinks of the same depth or three lavatories immediately adjacent to each other and in the same room where the waste outlets are not more than 30 inches (762 mm) apart, and the trap is centrally located where three compartments are installed.

1002.0 Traps Protected by Vent Pipes.

1002.1 Vent Pipes. Each plumbing fixture trap, except as otherwise provided in this code, shall be protected against siphonage, backpressure, and air circulation shall be assured throughout the drainage system using a vent pipe installed in accordance with the requirements of this code.

1002.2 Fixture Traps. Each fixture trap shall have a protecting vent so located that the developed length of the trap arm from the trap weir to the inner edge of the vent shall be within the distance given in Table 1002.2 but in no case less than two times the diameter of the trap arm. 1002.3 Change of Direction. A trap arm shall be permitted to change direction without the use of a cleanout where such change of direction does not exceed 90 degrees (1.57 rad). Horizontal changes in the direction of trap arms shall be in accordance with Section 706.3.

Exception: For trap arms, 3 inches (80 mm) in diameter and larger, the change of direction shall not exceed 135 degrees (2.36 rad) without the use of a cleanout. 1002.4 Vent Pipe Opening. The vent pipe opening from soil or waste pipe, except for water closets and similar fixtures, shall not be below the weir of the trap.

1003.0 Traps – Described. 1003.1 General Requirements. Each trap, except for traps within an interceptor or similar device shall be selfcleaning. Traps for bathtubs, showers, lavatories, sinks, laun

dry sinks, floor drains, urinals, drinking fountains, dental units, and similar fixtures shall be of standard design, weight and shall be of ABS, cast-brass, cast-iron, lead, PP, PVC, or other approved material. An exposed and readily accessible drawn-copper alloy tubing trap, not less than 17 B & S Gauge (0.045 inch) (1.143 mm), shall be permitted to be used on fixtures discharging domestic sewage.

Exception s :

CPC § 603.2 Medium relevance — show source text

2025 CALIFORNIA PLUMBING CODE 337

REFERENCED STANDARDS

TABLE 1701.1 (continued) REFERENCED STANDARDS

STANDARD NUMBER	STANDARD TITLE	APPLICATION	REFERENCED SECTION
ASSE 1012-2009	Backflow Preventers with an Intermediate Atmospheric Vent	Backflow Protection	Table 603.2
ASSE 1013-2021	Reduced Pressure Principle Backflow Prevention Assemblies	Backflow Protection	Table 603.2
ASSE 1014-2020	Backflow Prevention Devices for Hand-Held Showers	Backflow Protection	417.3
ASSE 1015-2021	Double Check Backflow Prevention	Backflow Protection	Table 603.2
ASSE 1016-2017/ASME A112.1016-2017/CSA B125.16-2017	Automatic Compensating Valves for Individual Showers and Tub/Shower Combinations	Valves	408.4, 408.4.2(1)
ASSE 1018-2001 (R2021)	Trap Seal Primer Valves - Potable Water Supplied	Valves	1007.2
ASSE 1019-2011 (R2016)	Wall Hydrant with Backflow Protection and Freeze Resistance	Backflow Protection	Table 603.2
ASSE 1020-2020	Pressure Vacuum Breaker Assemblies	Backflow Protection	Table 603.2
ASSE 1022-2021	Backflow Preventer for Beverage Dispensing Equipment	Backflow Protection	Table 603.2, 603.5.12
ASSE 1023-2020	Electrically Heated or Cooled Water Dispensers	Appliances	417.6
ASSE 1024-2017 (R2021)	Dual Check Backflow Preventers	Backflow Protection	Table 603.2, 603.5.12
ASSE 1032-2004 (R2021)	Dual Check Valve Type Backflow Preventers for Carbonated Beverage Dispensers, Post Mix Type	Backflow Protection	603.5.12
ASSE 1035-2020	Laboratory Faucet Backflow Preventers	Backflow Protection	Table 603.2, 603.3.11
ASSE 1037-2020/ASME A112.1037-2020/CSA B125.37-2020	Pressurized Flushing Devices for Plumbing Fixtures	Backflow Protection	413.2
ASSE 1044-2015 (R2020)	Trap Seal Primer - Drainage Types and Electric Design Types	DWV Components	1007.

CPC § 716.1 Medium relevance — show source text
Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .716.1 Multiple installations . . . . . . . . . . . . . . . . . . . . . .H 701.2 Soil absorption . . . . . . . . . . . .Table H 201.1(2), H 301.1

SELF-CLEANING TRAPS . . . . . . . . . . . . . . . . . . . . .1003.1

SEPARATE PLUMBING AND

DRAINAGE SYSTEMS . . . . . . . . . . . . . . . . . . . . . . .311.0

SEPARATE VENTING . . . . . . . . . . . . . . . . . . . .811.6, 906.3

SEPARATORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1009.0

SEPTIC TANKS

Abandoned . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .722.2

Capacity . . . . . . . . . . . . . . . . . .H 201.0, Table H 201.1(1)

Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . .H 601.7

Connections to sewer prohibited . . . . . . . . . . . . . .714.3

Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . .H 501.0

Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .221.0

Location of . . . . . . . . . . . . . . . . . .H 101.8, Table H 101.8

Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .716.1

Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .H 501.8

SERVICE, AUTHORITY TO RENDER GAS . . . . . . . .1205.0

SERVICES/SYSTEMS AND UTILITIES . . . . . . . . . . . . .310.14

SETTING FIXTURES . . . . . . . . . . . . . . . . . . . . . . . . . .402.5

SETTLING TANKS . . . . . . . . . . . . . . . . . . . . . . . . . . . .902.1

SEWAGE

Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .221.0

Disposal of . . . . . . . . . . . . . .303.0, 709.0, 713.0, 714.0,
CPC § 505.2 Medium relevance — show source text
SECONDARY TEMPERATURE

LIMITING DEVICE . . . . . . . . . . . . . . . . . . . . . . . . . .505.2

SEDIMENT TRAPS . . . . . . . . . . . . . . . . . . .1210.7.2, 1212.9

SEEPAGE PITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . .H 701.0

Abandoned . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .722.2

Area of disposal . . . . . . . . . . . . . . . . . . . . . . . . .H 301.0 Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .H 701.1 Combination with disposal fields . . . . . . . . . . . .H 601.4 Connection to sewer prohibited . . . . . . . . . . . . . . .714.3

Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . .H 701.3

Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .221.0

2025 CALIFORNIA PLUMBING CODE 577

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INDEX

Location . . . . . . . . . . . . . . .721.0, H 101.8, Table H 101.8

Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .716.1 Multiple installations . . . . . . . . . . . . . . . . . . . . . .H 701.2 Soil absorption . . . . . . . . . . . .Table H 201.1(2), H 301.1

SELF-CLEANING TRAPS . . . . . . . . . . . . . . . . . . . . .1003.1

SEPARATE PLUMBING AND

DRAINAGE SYSTEMS . . . . . . . . . . . . . . . . . . . . . . .311.0

SEPARATE VENTING . . . . . . . . . . . . . . . . . . . .811.6, 906.3

SEPARATORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1009.0

SEPTIC TANKS

Abandoned . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .722.2

Capacity . . . . . . . . . . . . . . . . . .H 201.0, Table H 201.1(1)

Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . .H 601.7
CPC § 1323.13.3 Medium relevance — show source text
2, 1323.13.3| |1326.4 - 1326.10|1326.5 - 1326.11| |1505.6 - 1505.14|1505.5 - 1505.13| |Figure 1505.10|Figure 1505.9| |1506.6 - 1506.13|1506.5 - 1506.12| |1603.3 - 1603.4|1603.4 - 1603.5| |Table 1603.4|Table 1603.5| |1603.5 - 1603.19|1603.6 - 1603.20| |1603.20|1503.2.4| |L 402.9 - L 402.11|L 402.8 - L 402.10| |L 404.9 - L 404.12|L 404.8 - L 404.11| |L 411.5, L 411.6|L 411.2, L411.3| |L 411.7|L 411.4| |L 411.9 - L 411.12|L 411.5 - L 411.8|

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Uniform Plumbing Code – 2024 Edition:

The Uniform Plumbing Code is the most widely adopted plumbing code in the world. The 2024 edition contains complete “turnkey” requirements for the installation and maintenance of plumbing systems, all in one easy to use book.

Uniform Plumbing Code Illustrated Training Manual:

The UPC Illustrated Training Manual is an excellent reference for anyone involved in the plumbing industry. It contains an extensive definitions section and several hundred comprehensive technical diagrams and illustrations. It serves as a textbook, and it also is useful as a valuable tool for explaining the intent and use of the Code.

Uniform Plumbing Code Study Guide:

This book is the perfect complement to the UPC Illustrated Training Manual. Alone, it constitutes a complete self-study course for learning the UPC. It has hundreds of questions, general practice exams, and plumbing math, pipe sizing exercises and fitting identification. A big help in getting you ready for a certification exam!

Guide to Important Code Questions to the Uniform Plumbing Code:

An excellent reference for learning and understanding plumbing code changes and identifies code changes between editions. It is a useful tool for preparing code change proposals.

Uniform Mechanical Code – 2024 Edition:

The Uniform Mechanical Code contains complete requirements for the installation and maintenance of heating, ventilating, cooking and refrigeration systems.

Uniform Mechanical Code Illustrated Training Manual:

Contains technical diagrams and illustrations that demonstrate the intent and use of the UMC. A great reference for everyone involved in Mechanical HVACR design and installation.

Uniform Mechanical Code Study Guide:

CPC § 2.0 High relevance — show source text

dishwasher, or both)|11⁄2|2.0|2.0|––| |Laundry2 (with or without discharge from a clothes washer)|11⁄2|2.0|2.0|2.0| |Service or Mop Basin|2|––|3.0|3.0| |Service or Mop Basin|3|––|3.0|3.0| |Service, flushing rim|3|––|6.0|6.0| |Wash, each set of faucets|––|––|2.0|2.0| |Nonwater Urinal with Drain Cleansing Action|2|1.0|1.0|1.0| |Urinal, integral trap 1.0 GPF2|2|2.0|2.0|5.0| |Urinal, integral trap greater than 1.0 GPF|2|2.0|2.0|6.0| |Urinal, exposed trap2|11⁄2|2.0|2.0|5.0| |Water Closet, 1.6 GPF Gravity Tank6|3|3.0|4.0|6.0| |Water Closet, 1.6 GPF Flushometer Tank6|3|3.0|4.0|6.0| |Water Closet, 1.6 GPF Flushometer Valve6|3|3.0|4.0|6.0|

2025 CALIFORNIA PLUMBING CODE 167

SANITARY DRAINAGE

TABLE 702.1 DRAINAGE FIXTURE UNIT VALUES (DFU) (continued)

PLUMBING APPLIANCES, APPURTENANCES, OR FIXTURES	MINIMUM SIZE TRAP AND TRAP ARM7 (inches)	PRIVATE	PUBLIC	ASSEMBLY8
Water Closet, greater than 1.6 GPF Gravity Tank6	3	4.0	6.0	8.0
Water Closet, greater than 1.6 GPF Flushometer Valve6	3	4.0	6.0	8.0

For SI units: 1 inch = 25 mm

CPC § 2.2 Medium relevance — show source text

For drainage fixture unit values related to lots within special occupancy parks in all parts of the State of Cal-_ ifornia, see California Code of Regulations, Title 25, Division 1, Chapter 2.2, Article 5, Section 2268.

required, and the unit equivalent of fixtures and devices not shown in Table 702.1 shall be based on the size of trap or trap

arm.

Maximum drainage fixture units for a fixture trap and trap arm loadings for sizes up to 4 inches (100 mm) shall be in accordance with Table 702.1(1).

TABLE 702.1(1) MAXIMUM DRAINAGE FIXTURE UNITS FOR A

TRAP AND TRAP ARM*

SIZE OF TRAP AND TRAP ARM (inches)	DRAINAGE FIXTURE UNIT VALUES (DFU)
11⁄4	1 unit
11⁄2	3 units
2	4 units
3	6 units
4	8 units

For SI Units: 1 inch = 25 mm

*** Exception:** On self-service laundries.

TABLE 702.1(1) MAXIMUM DRAINAGE FIXTURE UNITS FOR A

TRAP AND TRAP ARM*

For SI Units: 1 inch = 25 mm

*** Exception:** On self-service laundries.

TABLE 702.2

DISCHARGE CAPACITY IN GALLONS PER MINUTE FOR

INTERMITTENT FLOW ONLY*

GPM	FIXTURE UNITS
Up to 71⁄2	Equals 1 Fixture Unit
Greater than 71⁄2 to 15	Equals 2 Fixture Units
Greater than 15 to 30	Equals 4 Fixture Units
Greater than 30 to 50	Equals 6 Fixture Units

For SI units: 1 gallon per minute = 0.06 L/s

Discharge capacity exceeding 50 gallons per minute (3.15 L/s) shall be determined by the Authority Having Jurisdiction.

702.3 Continuous Flow. For a continuous flow into a drainage system, such as from a pump, sump ejector, air conditioning equipment, or similar device, 2 fixture units shall be equal to each gallon per minute (gpm) (L/s) of flow.

703.0 Size of Drainage Piping. 703.1 Minimum Size. The minimum sizes of vertical, horizontal, or both drainage piping shall be determined from the total of fixture units connected thereto, and additionally, in the case of vertical drainage pipes, in accordance with their length.

703.2 Maximum Number of Fixture Units. Table 703.2

shows the maximum number of fixture units allowed on a vertical or horizontal drainage pipe, building drain, or building sewer of a given size; the maximum number of fixture units allowed on a branch interval of a given size; and the maximum length (in feet and meters) of a vertical drainage pipe of a given size. 703.3 Sizing per Appendix C. For alternate method of sizing drainage piping, see Appendix C.

CPC § 910.0 Medium relevance — show source text
910.0 Combination Waste and Vent Systems. 910.1 Where Permitted. Combination waste and vent systems shall be permitted where structural conditions preclude the installation of conventional systems as otherwise prescribed by this code. 910.2 Approval. Construction documents for each combination waste and vent system shall first be approved by the Authority Having Jurisdiction before a portion of such system is installed.

910.3 Vents. Each combination waste and vent system, as defined in Chapter 2, shall be provided with a vent or vents adequate to ensure free circulation of air. A branch exceeding 15 feet (4572 mm) in length shall be separately vented in an approved manner. The area of a vent installed in a combination waste and vent system shall be not less than one-half the inside cross-sectional area of the drainpipe served. The vent connection shall be downstream of the uppermost fixture. 910.4 Connections and Size. Branches serving traps shall connect to the main line at an angle not exceeding 2 percent. Each waste pipe and each trap in such a system shall be not less than two pipe sizes exceeding the sizes required by Chapter 7 of this code, and not less than two pipe sizes exceeding a fixture tailpiece or connection. 910.5 Vertical Waste Pipe. No vertical waste pipe shall be used in such a system, except the tailpiece or connection between the outlet of a plumbing fixture and the trap. Such tailpieces or connections shall be as short as possible, and in no case shall exceed 2 feet (610 mm).

Exception: Branch lines shall be permitted to have 45 degree (0.79 rad) vertical offsets.

910.6 Cleanouts. An accessible cleanout shall be installed in each vent for the combination waste and vent system. Cleanouts shall not be required on a wet-vented branch serving a single trap where the fixture tailpiece or connection is not less than 2 inches (50 mm) in diameter and provides ready access for cleaning through the trap.

910.7 Fixtures. No water closet or urinal shall be installed on such a system. Other one, two, or three unit fixtures remotely located from the sanitary system and adjacent to a combination waste and vent system shall be permitted to be connected to such system in the conventional manner by means of waste and vent pipes of regular sizes, providing that the two pipe size increase required in Section 910.4 is based on the total fixture unit load connected to the system.

See Appendix B of this code for explanatory notes on the design of combination waste and vent systems.

911.0 Circuit Venting. 911.1 Circuit Vent Permitted. A maximum of eight flooroutlet water closets, showers, bathtubs, or floor drains con

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), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

VENTS

nected to a horizontal branch shall be permitted to be circuit vented. Each trap arm shall connect horizontally to the horizontal branch being circuit vented in accordance with Table 1002.2. The horizontal branch shall be classified as a drain and a vent from the most downstream trap arm connection to the most upstream trap arm connection to the horizontal branch.

Exception: Back-outlet and wall-hung water closets shall be permitted to be circuit vented provided that no floor-outlet fixtures are connected to the same horizontal branch. Backoutlet and wall-hung water closets shall connect horizontally to the horizontal circuit vented drain.
CPC § 11B-134 Medium relevance — show source text
DIVISION 9 – BUILT-IN ELEMENTS . . . . . . . . . . . . . . . . . . 11B-134

11B-901 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11B-134

11B-902 Dining Surfaces and Work Surfaces. . . . . . . . . . . . .11B-134

CONTENTS

11B-903 Benches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11B-134

11B-904 Check-Out Aisles and Sales and Service

Counters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11B-135

DIVISION 10 – RECREATION FACILITIES . . . . . . . . . . . . . . 11B-137

11B-1001 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11B-137

11B-1002 Amusement Rides. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11B-137

11B-1003 Recreational Boating Facilities . . . . . . . . . . . . . . . . 11B-138

11B-1004 Exercise Machines and Equipment . . . . . . . . . . . . . 11B-141

11B-1005 Fishing Piers and Platforms. . . . . . . . . . . . . . . . . . . . 11B-141

11B-1006 Golf Facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11B-142

11B-1007 Miniature Golf Facilities. . . . . . . . . . . . . . . . . . . . . . . . 11B-142

11B-1008 Play Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11B-143

11B-1009 Swimming Pools, Wading Pools and Spas . . . . . . 11B-145

11B-1010 Shooting Facilities with Firing Positions . . . . . . . . 11B-151

CHAPTER 12 INTERIOR ENVIRONMENT . . . . . . . . . . . . . . 12-1

1201 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-3

1202 Ventilation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-3
CPC § 10-5 Medium relevance — show source text
CHAPTER 10 MEANS OF EGRESS. . . . . . . . . . . . . . . . . . . . 10-5

1001 Administration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5

1002 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5

1003 General Means of Egress . . . . . . . . . . . . . . . . . . . . . . . 10-6 1004 Occupant Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-8 1005 Means of Egress Sizing. . . . . . . . . . . . . . . . . . . . . . . . 10-10 1006 Numbers of Exits and Exit Access Doorways. . . . . 10-11 1007 Exit and Exit Access Doorway Configuration . . . . 10-15 1008 Means of Egress Illumination . . . . . . . . . . . . . . . . . . 10-16 1009 Accessible Means of Egress. . . . . . . . . . . . . . . . . . . . 10-17 1010 Doors, Gates and Turnstiles . . . . . . . . . . . . . . . . . . . 10-20 1011 Stairways. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-30 101 2 Ramps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-34 1013 Exit Signs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-35 1014 Handrails. . . . . . . . . . . . . . . . . . . . . .
CPC § 1004.2 Medium relevance — show source text
1004.2 Movable Parts. Bladders, check valves or another type of devices with moveable parts shall be prohibited to serve as a trap.

1005.0 Trap Seals. 1005.1 General. Each fixture trap shall have a liquid seal of not less than 2 inches (51 mm) and not more than 4 inches (102 mm), except where a deeper seal is found necessary by the Authority Having Jurisdiction. Traps shall be set true with respect to their liquid seals and, where necessary, they shall be protected from freezing.

1006.0 Floor Drain Traps. 1006.1 General. Floor drains shall connect into a trap so constructed that it can be readily cleaned and of a size to serve efficiently the purpose for which it is intended. The drain inlet shall be so located that it is in full view. Where subject to the reverse flow of sewage or liquid waste, such drains shall be equipped with an approved backwater valve.

1007.0 Trap Seal Protection. 1007.1 General. Floor drain or similar traps directly connected to the drainage system and subject to infrequent use shall be protected with a trap seal primer, except where not deemed necessary for safety or sanitation by the Authority Having Jurisdiction. Trap seal primers shall be accessible for maintenance.

1007.2 Trap Seal Primers. Potable water supply trap seal primer valves shall comply with ASSE 1018. Drainage or electronic design type trap seal primer devices shall comply with ASSE 1044 or IAPMO PS 76.

1008.0 Building Traps. 1008.1 General. Building traps shall not be installed except where required by the Authority Having Jurisdiction. Each building trap where installed shall be provided with a cleanout and with a relieving vent or fresh-air intake on the inlet side of the trap, which needs not be larger than one-half the diameter of the drain to which it connects. Such relieving vent or fresh-air intake shall be carried above grade and terminate in a screened outlet located outside the building.

1009.0 Interceptors (Clarifiers) and Separators.

1009.1 Where Required. Interceptors (clarifiers) (including grease, oil, sand, solid interceptors, etc.) shall be required

by the Authority Having Jurisdiction where they are necessary for the proper handling of liquid wastes containing grease, flammable wastes, sand, solids, acid or alkaline substances, or other ingredients harmful to the building drainage system, the public or private sewer, or to public or private sewage disposal. A list of acceptable interceptor standards is referenced in Table 1009.1.

TABLE 1009.1 APPROVED INTERCEPTORS (CLARIFIERS)

CPC § 1009.1 Medium relevance — show source text

TABLE 1009.1 APPROVED INTERCEPTORS (CLARIFIERS)

APPLICATION	STANDARD
Fats, Oil, Grease (FOG)	ASME A112.14.3, ASME A112.14.4, ASME A112.14.6, CSA B481, ANSI/CAN/IAPMO Z1001, PDI G-101, PDI G-102
Solid Waste	IAPMO IGC 167
Non-petroleum Oil	ASME A112.14.6, IAPMO PS 80, PDI G-102
Petroleum Oil	ASTM D6104, IAPMO IGC 183, IAPMO IGC 325

1009.2 Approval. The size, type, and location of each interceptor (clarifier) or separator shall be approved by the Authority Having Jurisdiction. Except where otherwise specifically permitted, no wastes other than those requiring treatment or separation shall be discharged into an interceptor (clarifier). 1009.3 Design. Interceptors (clarifiers) for sand and similar heavy solids shall be so designed and located as to be readily accessible for cleaning and shall have a water seal of not less than 6 inches (152 mm). 1009.4 Relief Vent. Interceptors (clarifiers) shall be so designed that they will not become air-bound where closed covers are used. Each interceptor (clarifier) shall be properly vented.

1009.5 Location. Each interceptor (clarifier) cover shall be readily accessible for servicing and maintaining the interceptor (clarifier) in working and operating condition. The use of ladders or the removal of bulky equipment to service interceptors (clarifiers) shall constitute a violation of accessibility. Location of interceptors (clarifiers) shall be shown on the approved building plan. 1009.6 Maintenance of Interceptors. Interceptors shall be maintained in efficient operating condition by periodic removal of accumulated grease, scum, oil, or other floating substances and solids deposited in the interceptor. 1009.7 Discharge. The waste pipe from oil and sand interceptors shall discharge as approved by the Authority Having Jurisdiction.

1010.0 Slaughterhouses, Packing Establishments, etc.

1010.1 General. A fish, fowl, and animal slaughterhouse or establishment; a fish, fowl, and meat packing or curing establishment; a soap factory, tallow-rendering, fat-rendering, and a hide-curing establishment shall be connected to and shall drain or discharge into an approved grease interceptor (clarifier).

TABLE 1009.1 APPROVED INTERCEPTORS (CLARIFIERS)

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1010.2 Meat and Poultry Processing Plants. [AGR]

1010.2.1 Drainage and Plumbing Systems. Drainage and plumbing systems shall meet the require- ments of Section 724.0.

1010.2.1.1 Each floor drain shall be equipped with a deep-seal trap.

CPC § 413.3 Medium relevance — show source text
413.3 Flush Tanks. Flush tanks for manual flushing shall be equipped with a flush valve that complies with ASME A112.19.5/CSA B45.15 and an antisiphon fill valve (ballcock) that complies with ASSE 1002/ASME A112.1002/CSA B125.12 and installed in accordance with Section 603.5.2.

413.4 Water Supply for Flush Tanks. An adequate quantity of water shall be provided to flush and clean the fixture served. The water supply for flushing tanks and flushometer tanks equipped for manual flushing shall be controlled by a float valve or other automatic device designed to refill the tank after each discharge and to shut completely off the water flow to the tank where the tank is filled to operational capacity. Provision shall be made to automatically supply water to the fixture to refill the trap seal after each flushing. 413.5 Overflows in Flush Tanks. Flush tanks shall be provided with overflows discharging into the water closet or urinal connected thereto. Overflows supplied as original parts with the fixture shall be of sufficient size to prevent tank flooding at the maximum rate at which the tank is supplied with water under normal operating conditions and where installed in accordance with the manufacturer’s installation instructions.

414.0 Dishwashing Machines. 414.1 Application. Domestic dishwashing machines shall comply with UL 749. Domestic dishwashing machines containing sanitation features shall comply with NSF/ANSI 184 and UL 749.

Commercial dishwashing machines shall comply with NSF/ANSI 3 and UL 921.

414.2 Backflow Protection. The water supply connection to a commercial dishwashing machine shall be protected by an air gap or a backflow prevention device in accordance with Section 603.3.2, Section 603.3.5, Section 603.3.6, or that complies with ASSE 1004. 414.3 Drainage Connection. Domestic dishwashing machines shall discharge indirectly through an air gap fitting in accordance with Section 807.3 into a waste receptor, a wye branch fitting on the tailpiece of a kitchen sink, or dishwasher connection of a food waste disposer. Commercial dishwashing machines shall discharge indirectly through an air break in accordance with Section 807.1, or by a direct connection in accordance with Section 704.3.

414.4 Lead Content. Dishwashing machines shall comply with the lead content requirements of Section 604.2.

415.0 Drinking Fountains. 415.1 Application. Drinking fountains shall be self-closing and comply with ASME A112.19.1/CSA B45.2, ASME A112.19.2/CSA B45.1, or ASME A112.19.3/CSA B45.4. Drinking fountains and bottle filling stations shall also comply with NSF/ANSI/CAN 61. Permanently installed electric water coolers and bottle filling stations shall also comply with UL 399.

[HCD 1] Drinking fountains shall be installed and so regu- lated that a jet of water extending at least 2 inches (51 mm) in height from the water orifice shall be constantly available. The orifice shall not be accessible to the mouth of the drinker nor subject to immersion.

2025 CALIFORNIA PLUMBING CODE 65
CPC § 1305.2.3.3 Medium relevance — show source text
2, 1305.2.3.3, 1305.2.4.1, 1305.2.5, 1305.2.5.1, 1305.2.6, 1305.2.7.1, 1305.2.8, 1305.2.9, 1305.2.9.1, 1305.2.10, 1305.2.10.1, 1305.2.11, 1305.2.11.1, 1305.2.12.1, 1305.2.13, Table 1305.2.15, 1305.2.15.1, 1305.2.16.1, 1305.2.17, 1305.2.17.1, 1305.2.18, 1305.2.18.1, 1305.2.19, Table 1305.2.19, 1305.2.20, 1305.2.20.1, 1307.1.1, 1401.2, 1402.1, 1402.2, 1402.2.1, 1402.3, 1402.4, 1402.5, 1402.6, 1501.5, 1504.1.1, 1504.1.4.1, 1504.1.7, 1509.1, 1509.3, 1510.1

CEC — 25 : California Energy Code

302.2, 702.7, 708.1, 809.1, 907.1, 1104.1

CFC—25: California Fire Code

101.2.2, 101.4.2, 301.3.1, 302.2, 307.1, 308.1, 802.2.1, 802.2.3, 803.2.3, 803.4.1.1, 803.4.1.2, 803.4.1.3, 803.4.1.4, 803.4.1.5, 803.4.1.6, Table 804.5.1.1(1), 904.1.5, 1011.6.1.1, 1303.1.2, 1305.2.8.1, 1305.2.14, 1305.2.14.1, 1401.2, 1501.1, 1501.5, 1502.1, 1502.1.1, 1502.2, 1502.3, 1504.1, 1507.1, 1507.2

CMC—25: California Mechanical Code

302.2, 702.7, 807.1, 902.1.1, 1008.1, 1305.2.7.1, 1305.2.8, 1305.2.8.1

CPC—25: California Plumbing Code

302.2, 408.1, 702.7, 1009.1, 1009.2, 1009.3, 1009.5, 1302.1.6, 1503.1
CPC § 31-2022 Medium relevance — show source text
2025 CALIFORNIA PLUMBING CODE 453

), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

454 2025 CALIFORNIA PLUMBING CODE

), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

"The information contained in this appendix is not part of this American National Standard (ANS) and has not been processed in accordance with ANSI's requirements for an ANS. As such, this appendix may contain material that has not been subjected to public review or a consensus process. In addition, it does not contain requirements necessary for conformance to the standard."

The following IAPMO Installation Standard is included here for the convenience of the users of the Uniform Plumbing Code. It is not considered as a part of the Uniform Plumbing Code unless formally adopted as such. This Installation Standard is an independent, stand-alone document published by the International Association of Plumbing and Mechanical Officials and is printed herein by the expressed written permission of IAPMO.

INSTALLATION STANDARD FOR PEX TUBING SYSTEMS

FOR HOT- AND COLD-WATER DISTRIBUTION

IAPMO IS 31-2022

The provisions contained in this appendix are not mandatory unless specifically adopted by a state agency, or referenced in the adopting ordinance.

1 Scope

1.1 General

1.1.1 This Standard specifies requirements for the installation of SDR 9 CTS crosslinked polyethylene (PEX) tubing and fittings, including cold-expansion, crimp, press, and mechanical compression fittings, intended for hot- and cold-water distribution systems within buildings.

1.1.2 This Standards applies to

(a) SDR 9 CTS PEX tubing complying with ASTM F876 and pressure-rated in accordance with PPI TR-3; and (b) PEX fitting systems complying with (i) ASTM F877, for mechanical compression fittings and metal or plastic insert fittings with stainless steel press sleeves; (ii) ASTM F1807 or ASTM F2159, for metal or plastic insert fittings with copper crimp rings; (iii) ASTM F1960, for cold expansion fittings with PEX reinforced rings; or (iv) ASTM F2080, for cold expansion fittings with metal compression sleeves. 1.2 Terminology

In this Standard,

(a) “shall” is used to express a requirement, i.e., a provision that the user is obliged to satisfy to comply with the Standard; (b) “should” is used to express a recommendation, but not a requirement; (c) “may” is used to express an option or something permissible within the scope of the Standard; and (d) “can” is used to express a possibility or a capability. Notes accompanying sections of the Standard do not specify requirements or alternative requirements; their purpose is to separate explanatory or informa

tive material from the text. Notes to tables and figures are considered part of the table or figure and can be written as requirements.

1.3 Units of Measurement

SI units are the primary units of record in global commerce. In this Standard, the inch/pound units are shown in parentheses. The values stated in each measurement system are equivalent in application, but each unit system is to be used independently. All references to gallons are to U.S. gallons.

2 Reference Publications
CPC § 309.0 Medium relevance — show source text
2025 CALIFORNIA PLUMBING CODE 469

), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

IS 33

Uniform Plumbing Code References for Ductile Iron and PVC Pressure Building Supply and Exterior Cold-Water Piping

The following sections of the 2024 Uniform Plumbing Code apply to ductile iron and PVC pressure building supply and exterior cold-water piping.

Chapter 3 General Regulations

309.0 Workmanship

312.0 Protection of Piping, Materials, and Struc tures

313.0 Hangers, Supports, and Anchors

314.0 Trenching, Excavation, and Backfill

Chapter 6 Water Supply and Distribution

604.0 Materials (water piping)

Table 604.1 Materials for Building Supply and Water Distribution Piping and Fittings

605.4 Ductile Iron Pipe and Joints

605.12 PVC Plastic Pipe and Joints

605.16.2 Plastic Pipe to Other Materials

609.0 Installation, Testing, Unions, and Location

Abbreviations

IAPMO International Association of Plumbing and Mechanical Officials

UPC Uniform Plumbing Code published by IAPMO

AWWA American Water Works Association

CSA Canadian Standards Association

Applicable Standards.

ASME B16.4 Gray Iron Threaded Fittings Classes 125 and 250

ASTM D1785 Poly (Vinyl Chloride) (PVC) Plastic Pipe, Schedules 40, 80, and 120

ASTM D2241 Poly (Vinyl Chloride) (PVC) Pressure-Rated Pipe (SDR Series)

ASTM D2466 Poly (Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 40

ASTM D2467 Poly (Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 80

ASTM F1970 Special Engineered Fittings, Appurtenances or Valves for use in Poly (Vinyl Chloride) (PVC) or Chlorinated Poly (Vinyl Chloride) (CPVC) Systems

AWWA C110 Ductile Iron and Gray-Iron Fittings

AWWA C111 Rubber-Gasket Joints for Ductile-Iron Pressure Pipe and Fittings

AWWA C151 Ductile-Iron Pipe, Centrifugally Cast

AWWA C153 Ductile-Iron Compact Fitting

AWWA C900 Polyvinyl Chloride (PVC) Pressure Pipe and Fabricated Fittings, 4 in. through 12 in. (100 mm through 300 mm)

AWWA C904 Crosslinked Polyethylene (PEX) Pressure Tubing, ½ in. through 3 In. (13 mm through 76 mm), for Water Service

AWWA C907 Injection-Molded Polyvinyl Chloride (PVC) Pressure Fittings, 4 In, through 12 in (100 mm through 300 mm) for Water, Wastewater and Reclaimed Water Service

IAPMO/

ANSI UPC-1 Uniform Plumbing Code

470 2025 CALIFORNIA PLUMBING CODE

), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
CPC § 1.11.0. Medium relevance — show source text
This state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.0.

58 2025 CALIFORNIA PLUMBING CODE

), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

CHAPTER 4

PLUMBING FIXTURES AND FIXTURE FITTINGS

Note: In addition to the requirements of this chapter, buildings or facilities where accessibility is required for applications listed in California Code of Regulations, Title 24, Part 2 (California Building Code), Chapter 1, Section 1.9.1 regulated by the Division of the State Architect–Access Compliance shall also comply with Title 24, Part 2, Chapter 11A or 11B, as applicable under authority cited by CA Government Code Section 4450 and in reference cited by CA Government Code Sections 4450 through 4461, 12955.1(c), and CA Health and Safety Code Sections 18949.1, 19952 through 19959.

401.0 General.

401.1 Applicability. This chapter shall govern the materials and installation of plumbing fixtures, including faucets and fixture fittings, and the minimum number of plumbing fixtures required based on occupancy. 401.2 Quality of Fixtures. Plumbing fixtures shall be constructed of dense, durable, non-absorbent materials and shall have smooth, impervious surfaces, free from unnecessary concealed fouling surfaces. 401.3 Water-Conserving Fixtures and Fittings. Note 1: [BSC-CG & DSA-SS] Flow rates for specified plumbing fixtures for mandatory nonresidential construction are contained in Chapter 5, Division 5.3 of the California Green Building Standards Code (Part 11, Title 24, Califor- nia Code of Regulations - CALGreen). Scoping provisions applicable to nonresidential additions and alterations are contained in Section 301.3 of CALGreen. Note 2: [BSC-CG] On and after January 1, 2014, certain commercial real property, as defined in Civil Code Section 1101.3, shall have its noncompliant plumbing fixtures replaced with appropriate water-conserving plumbing fix- tures under specific circumstances. See Civil Code Section 1101.1 et seq. for definitions, types of commercial real prop- erty affected, effective dates, circumstances necessitating replacement of noncompliant plumbing fixtures, and duties and responsibilities for ensuring compliance.

[HCD-1] All noncompliant plumbing fixtures in any residen- tial real property shall be replaced with water-conserving plumbing fixtures. Plumbing fixture replacement is required prior to issuance of a certificate of final completion, certificate of occupancy, or final permit approval by the local building _department.
CPC § 4.1 Medium relevance — show source text
- 100°F
  (16°C-38°C)|1 h|6 h|2 h|12 h|6 h|24 h| |40°F-60°F
  (4°C-16°C)|2 h|12 h|4 h|24 h|12 h|48 h| |10°F- 40°F
  (-12°C+4°C)|8 h|48 h|16 h|96 h|48 h|8 days| |*If gaps or loose fits are encountered in the system, double these cure times.|*If gaps or loose fits are encountered in the system, double these cure times.|*If gaps or loose fits are encountered in the system, double these cure times.|*If gaps or loose fits are encountered in the system, double these cure times.|*If gaps or loose fits are encountered in the system, double these cure times.|*If gaps or loose fits are encountered in the system, double these cure times.|*If gaps or loose fits are encountered in the system, double these cure times.|
2025 CALIFORNIA PLUMBING CODE 467

), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

IS 33

FIGURE 1

LOCATION OF THRUST BLOCKS (STANDARD AND METRIC COMBINED) A COMPARISON OF THRUST-BLOCK AREAS (See Section 4.1)

468 2025 CALIFORNIA PLUMBING CODE

), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

IS 33

FIGURE 2

THRUST BLOCK BEARING AREA (See Section 5.2.2)

2025 CALIFORNIA PLUMBING CODE 469

), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

IS 33

Uniform Plumbing Code References for Ductile Iron and PVC Pressure Building Supply and Exterior Cold-Water Piping

The following sections of the 2024 Uniform Plumbing Code apply to ductile iron and PVC pressure building supply and exterior cold-water piping.

Chapter 3 General Regulations

309.0 Workmanship

312.0 Protection of Piping, Materials, and Struc tures

313.0 Hangers, Supports, and Anchors

314.0 Trenching, Excavation, and Backfill

Chapter 6 Water Supply and Distribution

604.0 Materials (water piping)

Table 604.1 Materials for Building Supply and Water Distribution Piping and Fittings

605.4 Ductile Iron Pipe and Joints

605.12 PVC Plastic Pipe and Joints

605.16.2 Plastic Pipe to Other Materials

609.0 Installation, Testing, Unions, and Location

Abbreviations

IAPMO International Association of Plumbing and Mechanical Officials

UPC Uniform Plumbing Code published by IAPMO

AWWA American Water Works Association

CSA Canadian Standards Association

Applicable Standards.

ASME B16.4 Gray Iron Threaded Fittings Classes 125 and 250

ASTM D1785 Poly (Vinyl Chloride) (PVC) Plastic Pipe, Schedules 40, 80, and 120

ASTM D2241 Poly (Vinyl Chloride) (PVC) Pressure-Rated Pipe (SDR Series)

Frequently asked questions

Can a mechanical check valve be used instead of a trap?

No. Bladders, check valves or other movable‑part devices are prohibited as traps by § 1004.2. Use an approved liquid‑seal trap made of approved materials instead.

What depth should I set the trap seal to?

Set the liquid seal to at least 2 inches and not more than 4 inches, unless the AHJ requires a deeper seal — see § 1005.1.

Are plastic traps allowed?

Yes — ABS and PVC (among others) are listed as acceptable trap materials in § 1003.1 so long as the design is standard and self‑cleaning.

My floor drain is rarely used — do I need anything special?

Floor drains subject to infrequent use should be protected with a trap seal primer (accessible for maintenance) unless the AHJ deems it unnecessary; primer devices have referenced standards in § 1007.1–1007.2.

Where do I find minimum trap diameters for each fixture?

Minimum trap sizes and trap‑arm sizes by fixture are listed in Table 702.1 (and Table 702.1(1)) of the CPC. Consult that table for fixture‑specific minimums.

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California Plumbing Code

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What the code requires — plain English

Requirements in detail

Materials and construction (what you may use)

Prohibited trap types

Trap seal depth (critical thresholds)

Decision‑relevant table (quick reference)

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