CPC · California Plumbing Code

Permitted vent materials and rules for changes in direction

Q: May galvanized steel or 304 stainless be buried underground as a vent?

No. § 903.1(1) states that galvanized steel and 304 stainless steel pipe shall not be installed underground and shall be at least 6 inches (152 mm) aboveground.

Q: What must I do after cutting a vent pipe in the field?

Remove burrs and ream to the full bore so the vent interior is smooth and unobstructed; this is mandatory per § 903.3 .

Q: If my job is governed by OSHPD, can I use ABS or PVC vents?

No — § 903.1.3 states ABS and PVC installations are not allowed for OSHPD (hospital) adoptions; use an accepted alternate material or seek AHJ direction.

Vent pipes must be made from materials listed for DWV in the CPC and meet agency limits (for example, ABS/PVC has fire and story‑height limits); turns in vent piping must be made with approved fittings (no bending or straining) and any cut edges must be reamed to full bore — see CPC **§ 903.0**, **§ 903.1**, and **§ 903.3**.

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Last reviewed: July 6, 2026

What the code requires — plain English

Vent piping and fittings must be made from materials that meet the standards listed for DWV piping (see the code’s materials table) and must follow the specific limits the CPC places on certain materials. The code also requires that any change in direction of a vent be made with approved fittings (no straining or bending of the vent pipe) and that burred ends be reamed to full bore. See § 903.0, § 903.1, and § 903.3 for these requirements.

The single most important rule: use only code-listed vent materials and make every turn with approved fittings — do not bend or strain the vent pipe, and ream any burred ends.

Requirements in detail

High‑level rules

Materials: Vent pipe and fittings shall comply with the applicable standards referenced in Table 701.2 (i.e., use materials listed for DWV applications). § 903.1 requires compliance with Table 701.2.
Underground restriction: No galvanized steel or 304 stainless steel pipe shall be installed underground; such pipe must be a minimum of 6 inches (152 mm) aboveground where used. § 903.1(1).
Plastic piping limits and fire requirements: ABS and PVC DWV installations must comply with the California Building Code firestopping/plenum requirements; outside of single‑family dwellings, materials exposed in ducts/plenums must meet flame‑spread and smoke‑development limits when required. § 903.1 (2).
Occupancy / agency limits: some state agency rules further restrict ABS/PVC — e.g., ABS/PVC installations are limited to not more than two stories of areas of residential accommodation under the HCD adoption; ABS/PVC may be prohibited by OSHPD in hospital facilities. See § 903.1.1 and § 903.1.3.
Changes in direction: All changes in the direction of vent piping must be made with appropriate approved fittings; vents must not be strained or bent. Burred ends must be reamed to full bore. § 903.3.

Decision table — quick reference

Decision dimension	Typical values / rule	What to do	Code Reference
Where to find permitted materials	Materials listed in Table 701.2	Select vent materials/fittings that are listed in Table 701.2 for DWV use	§ 903.1; Table 701.2
Galvanized steel / 304 SS	Not permitted underground; must be ≥ 6 in (152 mm) above ground	Do not bury galvanized or 304 SS vent pipe; route aboveground or use other permitted underground material	§ 903.1(1)
ABS / PVC DWV	Allowed subject to firestop/plenum rules; limited by some agencies (HCD/OSHPD)	For multistory residential check § 903.1.1; comply with California Building Code firestop rules for ducts/plenums	§ 903.1(2), § 903.1.1, § 903.1.3
Malleable iron vents	Must be galvanized where adopted by HCD	Specify galvanized malleable iron if using that material	§ 903.1.2
Change of direction	Must use approved fittings; no bending/straining; ream burred ends	Use factory bends or fittings approved for the pipe; do not field‑bend non‑approved materials; ream after cutting	§ 903.3

Installation/turn rules (practical)

Use manufactured elbow fittings or multiple 45° fittings rated for the pipe material — do not “cold‑bend” rigid plastics or strain metal pipe to make a turn. § 903.3.
After cutting any pipe, remove burrs and ream to the full bore so the vent interior is smooth and unobstructed. § 903.3.

Exceptions & special cases

Historical buildings: alternative materials may be accepted by the enforcing agency for historic preservation, but new non‑historical materials must comply with the regular code. (See the CHBC provisions when applicable.)
Single‑family dwellings: the CPC text specifically exempts single‑family dwelling units from some of the ABS/PVC fire‑exposure restrictions referenced in § 903.1(2) (i.e., more permissive for individual single‑family units). § 903.1(2).
State agency adoptions: HCD and OSHPD have overlays. For example: § 903.1.1 limits ABS/PVC to not more than two stories under HCD adoption; § 903.1.3 states that ABS/PVC installations are not allowed under OSHPD adoptions. Always check the applicable state/agency adoption table.

If a material or detail you plan to use is not clearly covered by § 903.0 / § 903.1 / § 903.3, get the specific referenced standard (Table 701.2 and Chapter 17 standards) or submit the product to the Authority Having Jurisdiction for approval. § 903.1 points users to the referenced standards; Table 701.2 lists permitted materials.

Common mistakes

Bending rigid vent pipe (PVC/ABS/cast iron) instead of using approved fittings — the code forbids straining or bending vent piping. § 903.3.
Forgetting to ream burred ends after cutting — burrs can trap debris or restrict flow; § 903.3 requires reaming to the full bore.
Installing galvanized steel or 304 stainless below grade — § 903.1(1) prohibits underground installation and requires 6 in (152 mm) aboveground.
Ignoring agency adoptions (HCD, OSHPD) that restrict ABS/PVC for certain occupancies or heights — check § 903.1.1 and § 903.1.3.
Using plastic vent runs through plenums without confirming flame‑spread/smoke requirements and fire‑stop compliance per § 903.1(2).

Worked example — concrete scenario

Scenario: You are installing a vent for a lavatory in a three‑story assisted‑living building (HCD‑adopted jurisdiction). You plan to use Schedule 40 PVC vent, and the run requires a 90° direction change.

Material permissibility check: Under the HCD adoption ABS/PVC installations are limited to not more than two stories (i.e., 3 stories would exceed that HCD limit). Therefore Schedule 40 PVC is not allowed for this three‑story building under § 903.1.1; choose an alternative material listed in Table 701.2 or seek AHJ approval. § 903.1.1.
If this had been a 2‑story residential building instead: PVC could be used only if you also meet the Building Code firestop/plenum requirements in § 903.1(2) (confirm flame‑spread/smoke limits where applicable) and verify Table 701.2 references.
Making the 90° change: use an approved 90° fitting or two 45° fittings rated for the vent material — do not bend the pipe, and after any cutting, ream the burred end to the full bore per § 903.3.

Numbers summary for this example:

Building = 3 stories → PVC not permitted under HCD for venting per § 903.1.1; select cast‑iron, copper (where allowed), or other Table 701.2 material and confirm agency adoption.
Turn method → approved fittings only (no bending) and ream cuts to full bore per § 903.3.

Related provisions (quick list)

§ 903.0 — Materials (chapter heading; see detailed subparts in § 903.1).
§ 903.1 — Applicable standards; limits on underground galvanized/304 SS, ABS/PVC fire/plenum limits, HCD/OSHPD adoptions.
§ 903.3 — Changes in direction — approved fittings; no bending/straining; ream burred ends.
Table 701.2 — Materials for drain/waste/vent pipe and fittings (use to select permitted vent materials).
§ 903.2 — (Related) Use and marking/weight requirements for copper tubing (see when copper is considered).
§ 706.0 — Changes in direction of drainage flow (useful for related drainage turn rules; vents refer to fittings per § 903.3).

Code references

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

CPC § 811.0. High relevance — show source text
defined in Section 811.0.

903.2.3 Marking. Copper or copper alloy tubing, in addition to the required incised marking, shall be marked in accordance with either ASTM B306 or ASTM B88. The colors shall be Type K, green; Type L, blue; Type M, red; and Type DWV, yellow. 903.3 Changes in Direction. Changes in the direction of vent piping shall be made by the appropriate use of approved fittings, and no such pipe shall be strained or bent. Burred ends shall be reamed to the full bore of the pipe.

904.0 Size of Vents.

904.1 Size. The size of vent piping shall be determined from its length and the total number of fixture units connected thereto, in accordance with Table 703.2. The diameter of an individual vent shall be not less than 1 [1] ⁄ 4 inches (32 mm) nor less than one-half the diameter of the drain to which it is connected. In addition, the drainage piping of each building and each connection to a public sewer or a private sewage disposal system shall be vented by means of one or more vent pipes, the aggregate cross-sectional area of which shall be not less than that of the largest required building sewer as determined from Table 703.2. Vent pipes from fixtures located upstream from pumps, ejectors, backwater valves, or other devices that obstruct the free flow of air and other gases between the building sewer and the outside atmosphere shall not be used for meeting the cross-sectional area venting requirements of this section. Exception: Where connected to a common building sewer, the drainage piping of two or more buildings located on the same lot and under one ownership shall be permitted to be vented by means of piping sized in accordance with Table 703.2, provided the aggregate cross-sectional area of vents is not less than that of the largest required common building sewer. 904.2 Length. Not more than one-third of the total permitted length, in accordance with Table 703.2, of a minimumsized vent shall be installed in a horizontal position. Where a minimum-sized vent is increased one pipe size for its entire length, the maximum length limitation shall not apply.

2025 CALIFORNIA PLUMBING CODE 189

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VENTS

905.0 Vent Pipe Grades and Connections. 905.1 Grade. Vent and branch vent pipes shall be free from drops or sags, and each such vent shall be level or shall be so graded and connected as to drip back by gravity to the drainage pipe it serves. 905.2 Horizontal Drainage Pipe. Where vents connect to a horizontal drainage pipe, each vent pipe shall have its invert taken off above the drainage centerline of such pipe downstream of the trap being served. 905.3 Vent Pipe Rise. Unless prohibited by structural conditions, each vent shall rise vertically to a point not less than 6 inches (152 mm) above the flood-level rim of the fixture served before offsetting horizontally, and where two or more vent pipes converge, each such vent pipe shall rise to a point not less than 6 inches (152 mm) in height above the floodlevel rim of the plumbing fixture it serves before being connected to any other vent. Vents less than 6 inches (152 mm) above the flood-level rim of the fixture shall be installed with approved drainage fittings, material, and grade to the drain.
CPC § 903.1.1 High relevance — show source text
(2) ABS and PVC DWV piping installations shall be in accordance with the firestop protection requirements in the California Building Code . Except for individual single-family dwelling units, materials exposed within ducts or plenums shall have a flame-spread index of not more than 25 and a smoke-developed index of not more than 50 where tested in accordance with ASTM E84 or UL 723. Plastic piping installed in plenums shall be tested in accordance with all requirements of ASTM E84 or UL 723. Mounting methods, supports and sample sizes of materials for testing that are not specified in ASTM E84 or UL 723 shall be prohibited.

903.1.1 [HCD 1 & HCD 2] ABS or PVC installations are limited to not more than two stories of areas of resi- dential accommodation.

903.1.2 [HCD 1] All malleable iron vents shall be gal- vanized.

903.1.3 [OSHPD 1, 2, 3, 4 & 5] ABS and PVC instal- lations are not allowed.

903.2 Use of Copper or Copper Alloy Tubing. Copper or copper alloy tube for underground drainage and vent piping shall have a weight of not less than that of copper or copper alloy drainage tube type DWV. 903.2.1 Aboveground. Copper or copper alloy tube for aboveground drainage and vent piping shall have a weight of not less than that of copper or copper alloy drainage tube type DWV. 903.2.2 Prohibited Use. Copper or copper alloy tube shall not be used for chemical or industrial wastes as

defined in Section 811.0.

903.2.3 Marking. Copper or copper alloy tubing, in addition to the required incised marking, shall be marked in accordance with either ASTM B306 or ASTM B88. The colors shall be Type K, green; Type L, blue; Type M, red; and Type DWV, yellow. 903.3 Changes in Direction. Changes in the direction of vent piping shall be made by the appropriate use of approved fittings, and no such pipe shall be strained or bent. Burred ends shall be reamed to the full bore of the pipe.

904.0 Size of Vents.

904.1 Size. The size of vent piping shall be determined from its length and the total number of fixture units connected thereto, in accordance with Table 703.2. The diameter of an individual vent shall be not less than 1 [1] ⁄ 4 inches (32 mm) nor less than one-half the diameter of the drain to which it is connected. In addition, the drainage piping of each building and each connection to a public sewer or a private sewage disposal system shall be vented by means of one or more vent pipes, the aggregate cross-sectional area of which shall be not less than that of the largest required building sewer as determined from Table 703.2. Vent pipes from fixtures located upstream from pumps, ejectors, backwater valves, or other devices that obstruct the free flow of air and other gases between the building sewer and the outside atmosphere shall not be used for meeting the cross-sectional area venting requirements of this section.
CPC § 1002.2 High relevance — show source text
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 :

(1) Drawn-copper alloy tubing traps shall not be used for urinals. Each trap shall have the manufacturer’s name stamped legibly in the metal of the trap, and each tubing trap shall have the gauge of the tubing in addition to the manufacturer’s name. A trap shall have a smooth and uniform interior waterway.

(2) [HCD 1 & HCD 2] Non-water supplied urinals conform- ing to ASME A112.19.19-2016, Standard for Vitreous China Nonwater Urinals, or reference standards in Table 1701.1 for non-vitreous ceramic or plastic urinal fixtures.

TABLE 1002.2

HORIZONTAL LENGTHS OF TRAP ARMS (EXCEPT FOR WATER CLOSETS AND SIMILAR FIXTURES) [1, 2, 3]

TRAP ARM PIPE
DIAMETER (inches) DISTANCE TRAP TO
VENT MINIMUM
(inches) LENGTH MAXIMUM
(inches)

11⁄4 21⁄2 30

11⁄2 3 42

2 4 60

3 6 72

4 8 120

Exceeding 4 2 x Diameter 120

For SI units: 1 inch = 25.4 mm
CPC § 909.12.4 High relevance — show source text
909.12.4 Automatic control. Where completely automatic control is required or used, the automatic-control sequences shall be initiated from an appropriately zoned automatic sprinkler system complying with Section 903.3.1.1, manual controls provided with ready access for the fire department and any smoke detectors required by the engineering analysis.

909.13 Control air tubing. Control air tubing shall be of sufficient size to meet the required response times. Tubing shall be flushed clean and dry prior to final connections and shall be adequately supported and protected from damage. Tubing passing through concrete or masonry shall be sleeved and protected from abrasion and electrolytic action.

909.13.1 Materials. Control air tubing shall be hard drawn copper, Type L, ACR in accordance with ASTM B42, ASTM B43, ASTM B68/B68M, ASTM B88, ASTM B251 and ASTM B280. Fittings shall be wrought copper or brass, solder type, in accordance with ASME B16.18 or ASME B16.22. Changes in direction shall be made with appropriate tool bends. Brass compression-type fittings shall be used at final connection to devices; other joints shall be brazed using a BCuP5 brazing alloy with solidus above 1,100°F (593°C) and liquidus below 1,500°F (816°C). Brazing flux shall be used on copper-to-brass joints only.

Exception: Nonmetallic tubing used within control panels and at the final connection to devices, provided that all of the following conditions are met:
1. Tubing shall comply with the requirements of Section 602.3.5 of the California Mechanical Code .
2. Tubing and the connected device shall be completely enclosed within a galvanized or paint-grade steel enclosure having a minimum thickness of 0.0296 inch (0.7534 mm) (No. 22 gage). Entry to the enclosure shall be by copper tubing with a protective grommet of neoprene or Teflon or by suitable brass compression to male-barbed adapter.
3. Tubing shall be identified by appropriately documented coding.
4. Tubing shall be neatly tied and supported within the enclosure. Tubing bridging cabinets and doors or moveable devices shall be of sufficient length to avoid tension and excessive stress. Tubing shall be protected against abrasion. Tubing connected to devices on doors shall be fastened along hinges.
909.13.2 Isolation from other functions. Control tubing serving other than smoke control functions shall be isolated by automatic isolation valves or shall be an independent system.

909.13.3 Testing. Control air tubing shall be tested at three times the operating pressure for not less than 30 minutes without any noticeable loss in gauge pressure prior to final connection to devices.

909.14 Marking and identification. The detection and control systems shall be clearly marked at all junctions, accesses and terminations.

909.15 Control diagrams. Identical control diagrams showing all devices in the system and identifying their location and function shall be maintained current and kept on file with the fire code official, the fire department and in the fire command center in a format and manner approved by the fire code official.
CPC § 901.0 High relevance — show source text
TABLE OF CONTENTS

CHAPTER 9 VENTS . . . . . . . . . . . . . . . . . . . . .187

901.0 General . . . . . . . . . . . . . . . . . . . . .189

901.1 Applicability . . . . . . . . . . . . . . . . . .189

901.2 Vents Required . . . . . . . . . . . . . . .189

901.3 Trap Seal Protection . . . . . . . . . . .189

902.0 Vents Not Required . . . . . . . . . . .189

902.1 Interceptor . . . . . . . . . . . . . . . . . .189

902.2 Bars, Soda Fountains, and Counter . . . . . . . . . . . . . . . . . . . . .189

903.0 Materials . . . . . . . . . . . . . . . . . . . .189

903.1 Applicable Standards . . . . . . . . . .189

903.2 Use of Copper or Copper Alloy Tubing . . . . . . . . . . . . . . . . .189

903.3 Changes in Direction . . . . . . . . . .189

904.0 Size of Vents . . . . . . . . . . . . . . . .189

904.1 Size . . . . . . . . . . . . . . . . . . . . . . . .189

904.2 Length . . . . . . . . . . . . . . . . . . . . . .189

905.0 Vent Pipe Grades and Connections . . . . . . . . . . . . . . . . .190

905.1 Grade . . . . . . . . . . . . . . . . . . . . . .190

905.2 Horizontal Drainage Pipe . . . . . . .190

905.3 Vent Pipe Rise . . . . . . . . . . . . . . .190

905.4 Roof Termination . . . . . . . . . . . . .190

905.5 Location of Opening . . . . . . . . . . .190

905.6 Common Vertical Pipe . . . . . . . . .190

906.0 Vent Termination . . . . . . . . . . . . .190

906.1 Roof Termination . . . . . . . . . . . . .190

906.2 Clearance . . . . . . . . . . . . . . . . . . .190

906.3 Use of Roof . . . . . . . . . . . . . . . . .190

906.4 Outdoor Installations . . . . . . . . . . .190

906.5 Joints . . . . . . . . . . . . . . . . . . . . . .190

906.6 Lead . . . . . . . . . . . . . . . . . . . . . . .190

906.7 Frost or Snow Closure . . . . . . . . .190

907.0 Vent Stacks and Relief Vents . . . .190

907.1 Drainage Stack . . . . . . . . . . . . . . .190

907.2 Yoke Vent . . . . . . . . . . . . . . . . . . .190
CPC § 2.1 High relevance — show source text
E, M|49|75|75|75a| |B|49|100|75|100a| |F|49|75|75|100a| |H-1, H-2, H-3|3|NP|NP|25b| |H-4, H-5|10|NP|NP|75b| |I-2d, I-4|10|NP_i_|NP_i_|75a| |I-3_h_|10|NP|NP|100a| |R-1|10|NP|NP|75a| |R-2|20|NP|NP|125a| |R-2.1|10|NP|NP|75a| |R-2.2|20|NP|NP|125a| |R-3e_, R-3.1e_|20|NP|NP|125a, g| |R-4e|20|NP|NP|125a, g| |Sf|29|100|75|100a| |U|49|100|75|75a| |L|See Section 453.6.1|See Section 453.6.1|NP|NP| |For SI: 1 foot = 304.8 mm.
NP = Not Permitted.
a. Buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2. See Section 903 for occupancies where automatic sprin-
kler systems are permitted in accordance with Section 903.3.1.2.
b. Group H occupancies equipped throughout with an automatic sprinkler system in accordance with Section 903.2.5.
c. For a room or space used for assembly purposes having fixed seating, see Section 1030.8.
d. For the travel distance limitations_ and number of exit and exit access requirements for rooms and spaces_in Group I-2, see Section 407.4.
e. The common path of egress travel distance shall only apply in a Group R-3 occupancy located in a mixed occupancy_building_.
f. The length of common path of egress travel distance in a Group S-2 open parking garage shall be not more than 100 feet.
g. For the travel distance limitations in Groups R-3 and R-4 equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.3, see Section
1006.2.2.6.
h. For holding cells, see Section 408.3.11.
i. In accordance with Health and Safety Code Section 13113(d), there is no requirement for automatic sprinkler protection in an existing Group I-2 located in Type IA construction.|For SI: 1 foot = 304.8 mm.
NP = Not Permitted.
a. Buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2. See Section 903 for occupancies where automatic sprin-
kler systems are permitted in accordance with Section 903.3.1.2.
b. Group H occupancies equipped throughout with an automatic sprinkler system in accordance with Section 903.2.5.
c. For a room or space used for assembly purposes having fixed seating, see Section 1030.8.
d.
CPC § 609.0 High relevance — show source text
609.0 Installation, Testing, Unions, and Location. 609.1 Installation. Water piping shall be adequately supported in accordance with Table 313.3. Burred ends shall be reamed to the full bore of the pipe or tube. Changes in direction shall be made by the appropriate use of fittings, except that changes in direction in copper or copper alloy tubing shall be permitted to be made with bends, provided that such bends are made with bending equipment that does not deform or create a loss in the cross-sectional area of the tubing. Changes in direction are allowed with flexible pipe and tubing without fittings in accordance with the manufacturer’s instructions. Provisions shall be made for expansion in hotwater piping. Piping, equipment, appurtenances, and devices shall be installed in a workmanlike manner in accordance with the provisions and intent of the code. Building supply yard piping shall be not less than 12 inches (305 mm) below the average local frost depth. The cover shall be not less than 12 inches (305 mm) below finish grade. 609.2 Trenches. Water pipes shall not be run or laid in the same trench as building sewer or drainage piping con structed of clay or materials that are not approved for use within a building unless both of the following conditions are met: (1) The bottom of the water pipe shall be not less than 12 inches (305 mm) above the top of the sewer or drain line. (2) The water pipe shall be placed on a solid shelf excavated at one side of the common trench with a clear horizontal distance of not less than 12 inches (305 mm) from the sewer or drain line.

Water pipes crossing sewer or drainage piping constructed of clay or materials that are not approved for use within a building shall be laid not less than 12 inches (305 mm) above the sewer or drainpipe. 609.3 Under Concrete Slab. Water piping installed within a building and in or under a concrete floor slab resting on the ground shall be installed in accordance with the following requirements:

(1) Ferrous piping shall have a protective coating of an approved type; machine applied and in accordance with recognized standards. Field wrapping shall provide equivalent protection and shall be restricted to those short sections and fittings necessarily stripped for threading. Zinc coating (galvanizing) shall not be deemed adequate protection for piping or fittings. Approved nonferrous piping shall not be required to be wrapped.

(2) Copper or copper alloy tubing shall be installed without joints where possible. Where joints are permitted, they shall be brazed, and fittings shall be wrought copper.

For the purpose of this section, “within a building” shall mean within the fixed limits of the building foundation.

609.4 Testing. Upon completion of a section or of the entire hot and cold water supply system, the system shall be tested with water or air. The potable water test pressure shall be greater than or equal to the working pressure under which the system is to be used. The air pressure shall be a minimum of 50 psi (345 kPa). Plastic pipe shall not be tested with air. The piping system shall withstand the test pressure without showing evidence of leakage for a period of not less than 15 minutes.

Exception: PEX, PP or PE-RT tube shall be permitted to be tested with air where permitted by the manufacturer’s instructions.
CPC § 1101.3 High relevance — show source text
1101.3 Storm Water Drainage to Sanitary Sewer Pro- hibited. Storm water shall not be drained into sewers intended for sanitary drainage. 1101.4 Material Uses. Pipe, tube, and fittings conveying rainwater shall be of such materials and design as to perform their intended function to the satisfaction of the Authority Having Jurisdiction. Conductors within a vent or shaft shall be of cast-iron, galvanized steel, wrought iron, copper, copper alloy, lead, Schedule 40 ABS DWV, Schedule 40 PVC DWV, stainless steel 304 or 316L [stainless steel 304 pipe and fittings shall not be installed underground and shall be kept not less than 6 inches (152 mm) aboveground], or other approved materials, and changes in direction shall be in accordance with the requirements of Section 706.0. ABS and PVC DWV piping installations shall be installed in accordance with applicable standards referenced in Chapter 17 and the firestop protection requirements in the California Building Code . Except for individual single-family dwelling units, materials exposed within ducts or plenums shall have a flame-spread index of not more than 25 and a smoke-developed index of not more than 50, where tested in accordance with ASTM E84 or UL 723. Plastic piping installed in plenums shall be tested in accordance with all requirements of ASTM E84 or UL 723. Mounting methods, supports and sample sizes of materials for testing that are not specified in ASTM E84 or UL 723 shall be prohibited.

[HCD 1 & HCD 2] ABS or PVC installations are limited to not more than two stories of areas of residential accommo- dation.

[OSHPD 1, 2, 3, 4 & 5] ABS and PVC installations are not allowed.

1101.4.1 Copper and Copper Alloys. Joints and connections in copper and copper alloy pipe and tube shall be installed in accordance with Section 705.3.

1101.4.2 Conductors. Conductors installed aboveground in buildings shall comply with the applicable standards referenced in Table 701.2 for aboveground drain, waste, and vent pipe. Conductors installed aboveground level shall be of seamless copper water tube, Type K, L, or M; Schedule 40 copper pipe or Schedule

40 copper alloy pipe; Type DWV copper drainage tube; service weight cast-iron soil pipe or hubless cast-iron soil pipe; standard weight galvanized steel pipe; stainless steel 304 or 316L [stainless steel 304 pipe and fittings shall not be installed underground and shall be kept not less than 6 inches (152 mm) aboveground], or Schedule 40 ABS or Schedule 40 PVC plastic pipe. 1101.4.2.1 [HCD 1] ABS or PVC installations are limited to not more than two stories of areas of res- idential accommodation.

1101.4.2.2 [OSHPD 1, 2, 3, 4 & 5] ABS and PVC installations are not allowed.
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 § 8-1 Medium relevance — show source text
CHAPTER 8 INTERIOR FINISHES. . . . . . . . . . . . . . . . . . . . . .8-1

801 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

802 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

803 Wall and Ceiling Finishes . . . . . . . . . . . . . . . . . . . . . . . . 8-3

804 Interior Floor Finish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6

805 Combustible Materials in Types I and II Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-7

806 Decorative Materials and Trim . . . . . . . . . . . . . . . . . . . 8-7

807 Insulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-8

808 Acoustical Ceiling Systems . . . . . . . . . . . . . . . . . . . . . . 8-8

CHAPTER 9 FIRE PROTECTION AND LIFE

SAFETY SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-1

901 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-7

902 Fire Pump and Riser Room Size . . . . . . . . . . . . . . . . . . 9-7

903 Automatic Sprinkler Systems . . . . . . . . . . . . . . . . . . . . 9-8

904 Alternative Automatic Fire-Extinguishing Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-17

905 Standpipe Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-20

906 Portable Fire Extinguishers . . . . . . . . . . . . . . . . . . . . . 9-22

907 Fire Alarm and Detection Systems . . . . . . . . . . . . . . . 9-25

908 Emergency Alarm Systems . . . . . . . . . . . . . . . . . . . . . 9-43

909 Smoke Control Systems . . . . . . . . . . . . . . . . . . . . . . . . 9-43

910 Smoke and Heat Removal . . . . . . . . . . . . . . . . . . . . . . 9-51
CPC § 6.6.1.4 Medium relevance — show source text
6.6.1.4 The number of fire appurtenances between sectional control valves is allowed to be modified by the authority having jurisdiction.

Revise Section 10.4.3.1.1 as follows:

10.4.3.1.1 Pipe joints shall not be located under foundation footings. The pipe under the building or building foundation shall not contain mechanical joints.

Exceptions:

1. Where allowed in accordance with 10.4.3.2.

2. Alternate designs may be utilized where designed by a registered professional engineer and approved by the enforcing agency.

Revise Section 10.9.1 as follows:

10.9.1 Backfill shall be well tamped in layers or puddle under and around pipes to prevent settlement or lateral movement. Backfill shall consist of clean fill sand or pea gravel to a minimum 6″ below and to a minimum of 12″ above the pipe and shall contain no ashes, cinders, refuse, organic matter or other corrosive materials. Other backfill materials and methods are permitted where designed by a registered professional engineer and approved by the enforcing agency.

25—13CA: California NFPA 25 Edition (Based on the 2011 Edition) Inspection, Testing and Maintenance of Water-based Fire Protection Systems Chapter 31F, 3108F

30—24: Flammable and Combustible Liquids Code

607.1, 5001.1, 5701.2, 5703.6.2, 5703.6.2.1, 5704.2.7, 5704.2.7.1, 5704.2.7.2, 5704.2.7.3.2, 5704.2.7.4, 5704.2.7.6, 5704.2.7.7, 5704.2.7.8, 5704.2.7.9, 5704.2.9.3, 5704.2.9.4, 5704.2.9.6.1.1, 5704.2.9.6.1.2, 5704.2.9.6.1.3, 5704.2.9.6.1.4, 5704.2.9.6.1.5, 5704.2.9.6.2, 5704.2.9.7.3, 5704.2.10.2, 5704.2.11.3, 5704.2.11.4.2, 5704.2.12.1, 5704.3.1, 5704.3.6, Table 5704.3.6.3(1), Table 5704.3.6.3(2), Table 5704.3.6.3(3), 5704.3.7.2.3, 5704.3.8.4, 5706.8.3

30A—24: Code for Motor Fuel Dispensing Facilities and Repair Garages

2301.4, 2301.5, 2301.6, 2306.6.3, 2310.1
CPC § 901.1 Medium relevance — show source text
901.1 Applicability. This chapter shall govern the materials, design, and installation of plumbing vent systems. 901.2 Vents Required. Each plumbing fixture trap, except as otherwise provided in this code, shall be protected against siphonage and backpressure, and air circulation shall be ensured throughout all parts of the drainage system by means of vent pipes installed in accordance with the requirements of this chapter and as otherwise required by this code. 901.3 Trap Seal Protection. The vent system shall be designed to prevent a trap seal from being exposed to a pressure differential that exceeds 1 inch water column (0.24 kPa) on the outlet side of the trap.

902.0 Vents Not Required.

902.1 Interceptor. Vent piping shall be permitted to be omitted on an interceptor where such interceptor acts as a primary settling tank and discharges through a horizontal indirect waste pipe into a secondary interceptor. The second interceptor shall be properly trapped and vented. 902.2 Bars, Soda Fountains, and Counter. Traps serving sinks that are part of the equipment of bars, soda fountains, and counters need not be vented where the location and construction of such bars, soda fountains, and counters are such as to make it impossible to do so. Where such conditions exist, said sinks shall discharge using approved indirect waste pipes into a floor sink or other approved type of recep tor.

903.0 Materials.

903.1 Applicable Standards. Vent pipe and fittings shall comply with the applicable standards referenced in Table 701.2, except that:

(1) No galvanized steel or 304 stainless steel pipe shall be installed underground and shall be not less than 6 inches (152 mm) aboveground.

(2) ABS and PVC DWV piping installations shall be in accordance with the firestop protection requirements in the California Building Code . Except for individual single-family dwelling units, materials exposed within ducts or plenums shall have a flame-spread index of not more than 25 and a smoke-developed index of not more than 50 where tested in accordance with ASTM E84 or UL 723. Plastic piping installed in plenums shall be tested in accordance with all requirements of ASTM E84 or UL 723. Mounting methods, supports and sample sizes of materials for testing that are not specified in ASTM E84 or UL 723 shall be prohibited.

903.1.1 [HCD 1 & HCD 2] ABS or PVC installations are limited to not more than two stories of areas of resi- dential accommodation.

903.1.2 [HCD 1] All malleable iron vents shall be gal- vanized.

903.1.3 [OSHPD 1, 2, 3, 4 & 5] ABS and PVC instal- lations are not allowed.

903.2 Use of Copper or Copper Alloy Tubing. Copper or copper alloy tube for underground drainage and vent piping shall have a weight of not less than that of copper or copper alloy drainage tube type DWV. 903.2.1 Aboveground. Copper or copper alloy tube for aboveground drainage and vent piping shall have a weight of not less than that of copper or copper alloy drainage tube type DWV. 903.2.2 Prohibited Use. Copper or copper alloy tube shall not be used for chemical or industrial wastes as

defined in Section 811.0.
CPC § 1.1 Medium relevance — show source text
1(2)_||||X||||||||||||||||||||| |903.1.1||||X|X|||||||||||||||||||| |903.1.2||||X||||||||||||||||||||| |903.1.3||||||||||X||X|X|X|X|||||||||| |906.2.1||||||||||X|X|X|X|X|X||||||||||

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 187

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

188 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 9

VENTS

901.0 General.

901.1 Applicability. This chapter shall govern the materials, design, and installation of plumbing vent systems. 901.2 Vents Required. Each plumbing fixture trap, except as otherwise provided in this code, shall be protected against siphonage and backpressure, and air circulation shall be ensured throughout all parts of the drainage system by means of vent pipes installed in accordance with the requirements of this chapter and as otherwise required by this code. 901.3 Trap Seal Protection. The vent system shall be designed to prevent a trap seal from being exposed to a pressure differential that exceeds 1 inch water column (0.24 kPa) on the outlet side of the trap.

902.0 Vents Not Required.

902.1 Interceptor. Vent piping shall be permitted to be omitted on an interceptor where such interceptor acts as a primary settling tank and discharges through a horizontal indirect waste pipe into a secondary interceptor. The second interceptor shall be properly trapped and vented. 902.2 Bars, Soda Fountains, and Counter. Traps serving sinks that are part of the equipment of bars, soda fountains, and counters need not be vented where the location and construction of such bars, soda fountains, and counters are such as to make it impossible to do so. Where such conditions exist, said sinks shall discharge using approved indirect waste pipes into a floor sink or other approved type of recep tor.

903.0 Materials.

903.1 Applicable Standards. Vent pipe and fittings shall comply with the applicable standards referenced in Table 701.2, except that:

(1) No galvanized steel or 304 stainless steel pipe shall be installed underground and shall be not less than 6 inches (152 mm) aboveground.

TRAP ARM PIPE DIAMETER (inches)	DISTANCE TRAP TO VENT MINIMUM (inches)	LENGTH MAXIMUM (inches)
11⁄4	21⁄2	30
11⁄2	3	42
2	4	60
3	6	72
4	8	120
Exceeding 4	2 x Diameter	120

CPC § 301.3. Medium relevance — show source text

form plumbing design work. Details are necessary to ensure compliance with the requirements of this section, together with a full description of the complete installation including quality, grade of materials, equipment, construction, and methods of assembly and installation. Components, materials, and equipment shall comply with standards and specifications listed in Chapter 17 of this code or approved by the Authority Having Jurisdiction and other national consensus standards applicable to plumbing systems and materials. Where such standards and specifications are not available, alternate materials and equipment shall be approved in accordance with Section 301.3.

390 2025 CALIFORNIA PLUMBING CODE

APPENDIX C

Col1	Col2	TABLE C 401.1 SIZE AND LENGTH OF VENTS	Col4	Col5	Col6	Col7	Col8	Col9	Col10	Col11
SIZE OF SOIL OR WASTE STACK (inches)	FIXTURE UNITS CONNECTED	DIAMETER OF VENT REQUIRED (inches)	DIAMETER OF VENT REQUIRED (inches)	DIAMETER OF VENT REQUIRED (inches)	DIAMETER OF VENT REQUIRED (inches)	DIAMETER OF VENT REQUIRED (inches)	DIAMETER OF VENT REQUIRED (inches)	DIAMETER OF VENT REQUIRED (inches)	DIAMETER OF VENT REQUIRED (inches)	DIAMETER OF VENT REQUIRED (inches)
SIZE OF SOIL OR WASTE STACK (inches)	FIXTURE UNITS CONNECTED	11⁄4	11⁄2	2	21⁄2	3	4	5	6	8
SIZE OF SOIL OR WASTE STACK (inches)	FIXTURE UNITS CONNECTED	MAXIMUM LENGTH OF VENT (feet)	MAXIMUM LENGTH OF VENT (feet)	MAXIMUM LENGTH OF VENT (feet)	MAXIMUM LENGTH OF VENT (feet)	MAXIMUM LENGTH OF VENT (feet)	MAXIMUM LENGTH OF VENT (feet)	MAXIMUM LENGTH OF VENT (feet)	MAXIMUM LENGTH OF VENT (feet)	MAXIMUM LENGTH OF VENT (feet)
11⁄2	8	50	150	––	––	––	––	––	––	––
2	12	30	75	200	––	––	––	––	––	––
2	20	26	50	150	––	––	––	––	––	––
21⁄2	42	––	30	1

CPC § 705.10 Medium relevance — show source text

Waste,
and Vent (DWV), Sewer, Sanitary, and Storm Plumbing Sys-
tems for Above and Below Ground Use|Joints|705.10|

340 2025 CALIFORNIA PLUMBING CODE

REFERENCED STANDARDS

TABLE 1701.1 (continued) REFERENCED STANDARDS

STANDARD NUMBER	STANDARD TITLE	APPLICATION	REFERENCED SECTION
ASTM C1540-2020	Standard Specification for Heavy-Duty Shielded Couplings Joining Hubless Cast Iron Soil Pipe and Fittings	Joints	705.2.2
ASTM C1563-2008 (R2021)	Standard Test Method for Gaskets for Use in Connection with Hub and Spigot Cast Iron Soil Pipe and Fittings for Sanitary Drain, Waste, Vent, and Storm Piping Applications	Joints	705.2.2
ASTM C1822-2021	Standard Specification for Insulating Covers on Accessible Lavatory Piping	Miscellaneous	403.3
ASTM D1253-2014	Standard Test Method for Residual Chlorine in Water	Miscellaneous	1506.10.6, 1603.4.1
ASTM D1785-2021a	Standard Specification for Poly (Vinyl Chloride) (PVC) Plastic Pipe, Schedules 40, 80, and 120	Piping	Table 604.1, Table 701.2
ASTM D2235-2021	Standard Specification for Solvent Cement for Acrylonitrile- Butadiene-Styrene (ABS) Plastic Pipe and Fittings	Joints	705.1.2
ASTM D2239-2021	Standard Specification for Polyethylene (PE) Plastic Pipe (SIDR-PR) Based on Controlled Inside Diameter	Piping	Table 604.1
ASTM D2241-2020	Standard Specification for Poly (Vinyl Chloride) (PVC) Pressure- Rated Pipe (SDR Series)	Piping	Table 604.1
ASTM D2464-2015	Standard Specification for Threaded Poly (Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 80	Fittings	Table 604.1
ASTM D2466-2021	Standard Specification for Poly (Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 40	Fittings	Table 604.1
ASTM D2467-2020	Standard Specification for Poly (Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 80	Fittings	Table 604.1
ASTM D2513-2020	Standard Specification for Polyethylene (PE) Gas Pressure Pipe, Tubing, and Fittings	Piping	1208.5.4, 1208.5.6.2, 1208.5.10.2, 1210.1.7.1(1)
ASTM D2564-2020	Standard Specification for Solvent Cements for Poly (Vinyl Chloride) (PVC) Plastic Piping Systems	Joints	605.12.2, 705.6.

CPC § 701.4 Medium relevance — show source text

701.4 Continuous Wastes. Continuous wastes and fixture tailpieces shall be constructed from the materials specified in Section 701.2 for drainage piping, provided, however, that such connections where exposed or accessible shall be permitted to be of seamless drawn brass not less than No. 20 B & S Gauge (0.032 inches) (0.8 mm). 701.5 Lead. (See Chapter 17) Sheet lead shall comply with the following:

(1) For safe pans – not less than 4 pounds per square foot (lb/ft [2] ) (19 kg/m [2] ) or [1] ⁄ 16 of an inch (1.6 mm) thick. (2) For flashings or vent terminals – not less than 3 lb/ft [2] (15 kg/m [2] ) or 0.0472 of an inch (1.2 mm) thick. (3) Lead bends and lead traps shall be not less than [1] ⁄ 8 of an inch (3.2 mm) in wall thickness. 701.6 Caulking Ferrules. Caulking ferrules shall be manufactured from copper or copper alloy and shall be in accordance with Table 701.6.

701.7 Soldering Bushings. Soldering bushings shall be of copper or copper alloy and shall be in accordance with Table 701.7.

TABLE 701.6

CAULKING FERRULES

PIPE SIZE (inches)	INSIDE DIAMETER (inches)	LENGTH (inches)	MINIMUM WEIGHT EACH	Col5
PIPE SIZE (inches)	INSIDE DIAMETER (inches)	LENGTH (inches)	pounds	ounces
2	21⁄4	41⁄2	1	0
3	31⁄4	41⁄2	1	12
4	41⁄4	41⁄2	2	8

For SI units: 1 inch = 25 mm, 1 pound = 0.453 kg, 1 ounce = 0.02834 kg

TABLE 701.7

SOLDERING BUSHINGS

PIPE SIZE (inches)	MINIMUM WEIGHT EACH	Col3	PIPE SIZE (inches)	MINIMUM WEIGHT EACH	Col6
PIPE SIZE (inches)	pounds	ounces	ounces	pounds	ounces
11⁄4	0	6	21⁄2	1	6
11⁄2	0	8	3	2	0
2	0	14	4	3	8

For SI units: 1 inch = 25 mm, 1 pound = 0.453 kg, 1 ounce = 0.02834 kg

702.0 Fixture Unit Equivalents. 702.1 Trap Size. The unit equivalent of plumbing fixtures shown in Table 702.1 shall be based on the size of the trap

TABLE 701.6

CAULKING FERRULES

CPC § 8-903.3 Medium relevance — show source text
8-903.3 Materials. New nonhistorical materials shall comply with the regular code requirements. The enforcing agency shall accept alternative materials which do not create a safety hazard where their use is necessary to maintain the historical integrity of the building.

8-903.4 Drainage and vent systems. Plumbing fixtures shall be connected to an adequate drainage and vent system. The enforcing agency may require operational tests for drainage and vent systems which do not comply with applicable requirements of the regular code. Vent terminations may be installed in any location which, in the opinion of the enforcing agency, does not create a safety hazard.

8-903.5 Indirect and special wastes. Indirect and special waste systems shall be installed so that no safety hazard is created. Chemical or industrial liquid wastes which may detrimentally affect the sanitary sewer system shall be pretreated to render them safe prior to discharge.

8-903.6 Traps and interceptors. Traps and interceptors shall comply with the regular code requirements except that the enforcing agency shall accept solutions which do not increase the safety hazard. Properly maintained “S” and drum traps may remain in use.

8-903.7 Joints and connections.

8-903.7.1 Joints and connections in new plumbing systems shall comply with applicable requirements of the regular code.

8-903.7.2 Joints and connections in existing or restored systems may be of any type that does not create a safety hazard.

8-903.8 Water distribution. Plumbing fixtures shall be connected to an adequate water distribution system. The enforcing agency may require operational tests for water distribution systems which do not comply with applicable requirements of the regular code. Prohibited (unlawful) connections and cross connections shall not be permitted.

8-903.9 Building sewers and private sewage disposal systems. New building sewers and new private sewage disposal systems shall comply with applicable requirements of the regular code.

20 2025 CALIFORNIA HISTORICAL BUILDING CODE

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

MECHANICAL, PLUMBING AND ELECTRICAL REQUIREMENTS

8-903.10 Fuel-gas piping. Fuel-gas piping shall comply with the regular code requirements except that the enforcing agency shall accept solutions which do not increase the safety hazard.

SECTION 8-904 — ELECTRICAL

8-904.1 General. Electrical systems shall comply with the regular code unless otherwise permitted by this code, or approved by the authority having jurisdiction.

8-904.1.1 The provisions of the CHBC shall apply to the acceptance, location, installation, alteration, repair, relocation, replacement or addition of any electrical system or portion thereof, the premise wiring, or equipment fixed in place as related to restoration within or attached to a qualified historical building or property.

8-904.1.2 Existing systems, wiring methods and electrical equipment which do not, in the opinion of the enforcing agency, constitute a safety hazard may remain in use.

8-904.1.3 The enforcing agency may approve any alternative to the CHBC which achieves equivalent safety.

8-904.1.4 Archaic methods that do not appear in present codes may remain and may be extended if, in the opinion of the enforcing agency, they constitute a safe installation.

8-904.2 Wiring methods.

CPC § 501.0 Medium relevance — show source text

THAN THREE BRANCH INTERVALS**| |DIAMETER OF
PIPE
(inches)|HORIZONTAL FIXTURE
BRANCH1|ONE STACK OF THREE
OR FEWER BRANCH
INTERVALS|TOTAL FOR STACK|TOTAL AT ONE BRANCH
INTERVAL| |11⁄2|3|4|8|2| |2|6|10|24|6| |21⁄2|12|20|42|9| |3|202|482|722|202| |4|160|240|500|90| |5|360|540|1100|200| |6|620|960|1900|350| |8|1400|2200|3600|600| |10|2500|3800|5600|1000| |12|3900|6000|8400|1500| |15|7000|6000|8400|1500|

For SI units: 1 inch = 25 mm

Notes:

1 Does not include branches of the building drain.

2 A maximum of two water closets or bathroom groups within each branch interval or more than six water closets or bathroom groups on the stack.

than the required size for the vent serving the drainage stack. The yoke vent connection shall be permitted to be a vertical extension of the drainage stack.

C 501.0 Vacuum Drainage Systems. C 501.1 General. This section regulates the design and installation provisions for vacuum waste drainage systems. Plans for vacuum waste drainage systems shall be submitted to the Authority Having Jurisdiction for approval and shall be considered an engineered designed system. Such plans shall be prepared by a registered design professional to per

390 2025 CALIFORNIA PLUMBING CODE

APPENDIX C

Col1	Col2	TABLE C 401.1 SIZE AND LENGTH OF VENTS	Col4	Col5	Col6	Col7	Col8	Col9	Col10	Col11
SIZE OF SOIL OR WASTE STACK (inches)	FIXTURE UNITS CONNECTED	DIAMETER OF VENT REQUIRED (inches)	DIAMETER OF VENT REQUIRED (inches)	DIAMETER OF VENT REQUIRED (inches)	DIAMETER OF VENT REQUIRED (inches)	DIAMETER OF VENT REQUIRED (inches)	DIAMETER OF VENT REQUIRED (inches)	DIAMETER OF VENT REQUIRED (inches)	**DIAMETER OF VENT REQUIRED

CPC § 8-903.2 Medium relevance — show source text
8-903.2 Residential occupancies.

8-903.2.1 Where toilet facilities are provided, alternative sewage disposal methods may be acceptable if approved by the local health department. In hotels, where private facilities are not provided, water closets at the ratio of one for each 15 rooms may be acceptable.

8-903.2.2 Toilet facilities are not required to be on the same floor or in the same building as sleeping rooms. Water-flush toilets may be located in a building immediately adjacent to the sleeping rooms. When alternative sewage disposal methods are utilized, they shall be located a minimum distance from the sleeping rooms or other locations as approved by the local health department.

8-903.2.3 Kitchen sinks shall be provided in all kitchens. The sink and countertop may be of any smooth nonabsorbent finish which can be maintained in a sanitary condition.

8-903.2.4 Hand washing facilities shall be provided for each dwelling unit and each hotel guest room. A basin and pitcher may be acceptable as adequate hand washing facilities.

8-903.2.5 Hot or cold running water is not required for each plumbing fixture, provided a sufficient amount of water is supplied to permit the fixture’s normal operation.

8-903.2.6 Bathtubs and lavatories with filler spouts less than 1 inch (25.4 mm) above the fixture rim may remain in use, provided there is an acceptable overflow below the rim.

8-903.2.7 Original or salvage water closets, urinals and flushometer valves shall be permitted in qualified historical buildings or properties. Historically accurate reproduction, nonlow-consumption water closets, urinals and flushometer valves shall be permitted except where historically accurate fixtures that comply with the regular code are available.

8-903.3 Materials. New nonhistorical materials shall comply with the regular code requirements. The enforcing agency shall accept alternative materials which do not create a safety hazard where their use is necessary to maintain the historical integrity of the building.

8-903.4 Drainage and vent systems. Plumbing fixtures shall be connected to an adequate drainage and vent system. The enforcing agency may require operational tests for drainage and vent systems which do not comply with applicable requirements of the regular code. Vent terminations may be installed in any location which, in the opinion of the enforcing agency, does not create a safety hazard.

8-903.5 Indirect and special wastes. Indirect and special waste systems shall be installed so that no safety hazard is created. Chemical or industrial liquid wastes which may detrimentally affect the sanitary sewer system shall be pretreated to render them safe prior to discharge.

8-903.6 Traps and interceptors. Traps and interceptors shall comply with the regular code requirements except that the enforcing agency shall accept solutions which do not increase the safety hazard. Properly maintained “S” and drum traps may remain in use.

8-903.7 Joints and connections.

8-903.7.1 Joints and connections in new plumbing systems shall comply with applicable requirements of the regular code.

8-903.7.2 Joints and connections in existing or restored systems may be of any type that does not create a safety hazard.

8-903.8 Water distribution. Plumbing fixtures shall be connected to an adequate water distribution system. The enforcing agency may require operational tests for water distribution systems which do not comply with applicable requirements of the regular code. Prohibited (unlawful) connections and cross connections shall not be permitted.

CPC § 0.453 Medium relevance — show source text

For SI units: 1 inch = 25 mm, 1 pound = 0.453 kg, 1 ounce = 0.02834 kg

TABLE 701.7

SOLDERING BUSHINGS

PIPE SIZE (inches)	MINIMUM WEIGHT EACH	Col3	PIPE SIZE (inches)	MINIMUM WEIGHT EACH	Col6
PIPE SIZE (inches)	pounds	ounces	ounces	pounds	ounces
11⁄4	0	6	21⁄2	1	6
11⁄2	0	8	3	2	0
2	0	14	4	3	8

For SI units: 1 inch = 25 mm, 1 pound = 0.453 kg, 1 ounce = 0.02834 kg

702.0 Fixture Unit Equivalents. 702.1 Trap Size. The unit equivalent of plumbing fixtures shown in Table 702.1 shall be based on the size of the trap

TABLE 701.6

CAULKING FERRULES

For SI units: 1 inch = 25 mm, 1 pound = 0.453 kg, 1 ounce = 0.02834 kg

TABLE 701.7

SOLDERING BUSHINGS

For SI units: 1 inch = 25 mm, 1 pound = 0.453 kg, 1 ounce = 0.02834 kg

2025 CALIFORNIA PLUMBING CODE 165

SANITARY DRAINAGE

TABLE 701.2 MATERIALS FOR DRAIN, WASTE, VENT PIPE AND FITTINGS

MATERIAL	UNDERGROUND DRAIN, WASTE, VENT PIPE AND FITTINGS	ABOVEGROUND DRAIN, WASTE, VENT PIPE AND FITTINGS	BUILDING SEWER PIPE AND FITTINGS	REFERENCED STAN- DARD(S) PIPE	REFERENCED STANDARD(S) FITTINGS
ABS (Schedule 40)	X	X	X	ASTM D2661, ASTM D2680*	ASME A112.4.4, ASTM D2661, ASTM D2680*
Cast-Iron	X	X	X	ASTM A74, ASTM A888, CISPI 301	ASME B16.12, ASTM A74, ASTM A888, CISPI 301
Co-Extruded ABS (Schedule 40)	X	X	X	ASTM F628	ASME A112.4.4, ASTM D2661, ASTM D2680*
Co-Extruded Composite (Schedule 40)	X	X	X	ASTM F1488	ASME A112.4.4, ASTM D2661, ASTM D2665, ASTM F794*, ASTM F1866
Co-Extruded PVC (Schedule 40)	X	X	X	ASTM F891,

CPC § 1.4 Medium relevance — show source text

340 2025 CALIFORNIA PLUMBING CODE

REFERENCED STANDARDS

TABLE 1701.1 (continued) REFERENCED STANDARDS

STANDARD NUMBER	STANDARD TITLE	APPLICATION	REFERENCED SECTION
ASTM C1540-2020	Standard Specification for Heavy-Duty Shielded Couplings Joining Hubless Cast Iron Soil Pipe and Fittings	Joints	705.2.2
ASTM C1563-2008 (R2021)	Standard Test Method for Gaskets for Use in Connection with Hub and Spigot Cast Iron Soil Pipe and Fittings for Sanitary Drain, Waste, Vent, and Storm Piping Applications	Joints	705.2.2
ASTM C1822-2021	Standard Specification for Insulating Covers on Accessible Lavatory Piping	Miscellaneous	403.3
ASTM D1253-2014	Standard Test Method for Residual Chlorine in Water	Miscellaneous	1506.10.6, 1603.4.1
ASTM D1785-2021a	Standard Specification for Poly (Vinyl Chloride) (PVC) Plastic Pipe, Schedules 40, 80, and 120	Piping	Table 604.1, Table 701.

Frequently asked questions

Can I field‑bend copper vent tubing instead of using fittings?

Yes — provided the bending method does not deform or reduce cross‑section and is performed with proper bending equipment; however, the vent change‑of‑direction rule for all vent piping still requires approved fittings or acceptable bends and that the pipe not be strained or bent improperly per § 903.3. Also see the copper‑specific rules in § 903.2.

Are ABS or PVC vents allowed in non‑residential buildings?

They are allowed only if they meet the California Building Code firestop/plenum requirements; outside of individual single‑family dwellings, exposed materials in ducts/plenums must meet flame‑spread and smoke limits. Check § 903.1(2) and the referenced Building Code provisions.

May galvanized steel or 304 stainless be buried underground as a vent?

No. § 903.1(1) states that galvanized steel and 304 stainless steel pipe shall not be installed underground and shall be at least 6 inches (152 mm) aboveground.

What must I do after cutting a vent pipe in the field?

Remove burrs and ream to the full bore so the vent interior is smooth and unobstructed; this is mandatory per § 903.3.

If my job is governed by OSHPD, can I use ABS or PVC vents?

No — § 903.1.3 states ABS and PVC installations are not allowed for OSHPD (hospital) adoptions; use an accepted alternate material or seek AHJ direction.

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