CPC · California Plumbing Code
How must fixtures be installed and secured (wall‑hung, floor‑mounted, closet flanges)?
Fixtures must be firmly attached: floor fixtures bolted to floor and drain, wall‑hung fixtures carried on structural metal supports (not on piping), and closet flanges sized, seated at the finished floor, and fastened with corrosion‑resistant hardware as required by the California Plumbing Code (§402.3–§402.6.3).
Last reviewed: July 6, 2026
What the code requires — plain English
Fixtures must be firmly attached so they cannot move or place strain on piping. Floor‑mounted fixtures must be bolted to the floor and the drainage connection; wall‑hung fixtures must be supported on structural metal members so no strain is transmitted to the plumbing connections; and closet flanges (closet rings) must be of approved materials, sized and secured to properly support the fixture. See § 402.3, § 402.4, § 402.6, § 402.6.1, § 402.6.2, § 402.6.3.
The single most important rule: fixtures must be rigidly supported and attached by approved, corrosion‑resistant hardware so the fixture cannot shift or transfer load to the plumbing joints.
Requirements in detail
Securing floor‑outlet and floor‑mounted fixtures (what § 402.3 requires)
- Floor‑outlet / floor‑mounted fixtures must be rigidly secured to the drainage connection and to the floor using screws or bolts of copper, copper alloy, or other equally corrosion‑resistant material. § 402.3.
Wall‑hung fixtures (what § 402.4 requires)
- Wall‑hung fixtures must be rigidly supported by metal supporting members so no strain is transmitted to the connections.
- Off‑the‑floor public fixtures and concealed‑tank water closets must use supports that comply with referenced ASME standards (ASME A112.6.1M and ASME A112.6.2). Flush tanks and similar appurtenances must be secured by approved non‑corrosive screws or bolts. § 402.4.
Flanged fixture connections (what § 402.6 requires)
- Connections between drainage pipe and water closets, floor‑outlet service sinks and urinals must use an approved flange or connection method (copper alloy, hard lead, ABS, PVC, iron; caulked, soldered, solvent‑cemented, rubber gasket, or screwed), and be bolted with an approved gasket, washer, or setting compound between the fixture and the connection.
- The bottom of the flange shall be set on the top of the finished floor. § 402.6.
Closet rings / closet flanges (what § 402.6.1 requires)
- Closet rings (closet flanges) must be of an approved type and may be constructed of copper alloy, copper, hard lead, cast‑iron, galvanized malleable iron, ABS, PVC or other approved materials.
- They shall be approximately 7 inches (178 mm) in diameter and, together with the soil pipe, present a 1-1/2 inch (38 mm) wide flange or face to receive the fixture gasket/closet seal.
- Caulked‑on closet rings must be at least 1/4 inch (6.4 mm) thick and 2 inches (51 mm) overall depth. Closet rings must be properly joined to the soil pipe (burned/soldered, caulked, solvent cemented, or screwed/fastened as appropriate) and shall be adequately designed and secured to support fixtures connected thereto. § 402.6.1.
Securing closet flanges (what § 402.6.2 requires)
- Closet screws, bolts, washers, and similar fasteners shall be of copper alloy, copper, or listed equally corrosion‑resistant materials.
- Fasteners must be of a size and number to properly support the fixture installed. § 402.6.2.
Securing floor‑mounted, back‑outlet water closet bowls (what § 402.6.3 requires)
- Floor‑mounted back‑outlet bowls must be set level with a 90° angle between floor and wall at the fixture outlet centerline. The floor and wall must provide a flat mounting surface not less than 5 inches (127 mm) to the right and left of the fixture outlet centerline.
- The closet flange shall be secured to the wall mounting surface; offset, eccentric, or reducing closet flanges are not permitted with these fixtures.
- The fixture must be secured to the wall outlet flange or drainage connection and to the floor by corrosion‑resistant screws or bolts. § 402.6.3.
Installation interface and gaskets
- Wall‑mounted water closets must be securely bolted to an approved carrier fitting which is securely attached to the structure. The connecting pipe must be approved material sized to accept a gasket; gasket materials include neoprene, felt, or similar approved types. § 402.6.
Quick reference table — decision‑relevant dimensions, materials and requirements
| Item | Value / Requirement | Code Reference |
|---|---|---|
| Flange bottom location | Set on top of finished floor | § 402.6 |
| Closet ring diameter (approx.) | 7 inches (178 mm) | § 402.6.1 |
| Flange/face width to receive gasket | 1‑1/2 inch (38 mm) | § 402.6.1 |
| Caulked‑on closet ring thickness | ≥ 1/4 inch (6.4 mm) | § 402.6.1 |
| Caulked‑on closet ring depth | ≥ 2 inches (51 mm) overall depth | § 402.6.1 |
| Wall/floor flat mounting surface (back‑outlet WC) | ≥ 5 inches (127 mm) each side of outlet centerline | § 402.6.3 |
| Angle requirement (back‑outlet WC) | 90° between floor and wall at outlet centerline | § 402.6.3 |
| Fastener material | Copper, copper alloy, or equally corrosion‑resistant | § 402.3; § 402.6.2 |
| Gasket materials (carrier fittings) | Neoprene, felt, or similar approved types | § 402.6 |
| Unsupported flanges | Offset/eccentric/reducing flanges not allowed (for certain back‑outlet WC) | § 402.6.3 |
Exceptions & special cases
- Supports for off‑the‑floor plumbing fixtures for public use must comply with ASME A112.6.1M; framing‑affixed supports for off‑the‑floor water closets with concealed tanks must comply with ASME A112.6.2 (see § 402.4).
- The code requires fixtures be installed per the manufacturer’s installation instructions; where a manufacturer provides specific fastening or support requirements, those instructions apply in addition to the CPC. See § 402.8 and § 402.9.
- Where the code specifies "size and number to properly support the fixture," the CPC intentionally defers to the fixture manufacturer and approved engineering judgment rather than fixed bolt counts; follow manufacturer guidance and local AHJ direction (see § 402.6.2).
Common mistakes
- Using ordinary steel hardware instead of corrosion‑resistant screws/bolts (violates § 402.3 / § 402.6.2).
- Allowing a wall‑hung fixture to be supported by the trap or waste connections (strain must not be transmitted to connections per § 402.4).
- Installing a closet flange below the finished floor plane or not seating the flange on the finished floor (violates § 402.6).
- Using offset, eccentric, or reducing closet flanges with floor‑mounted back‑outlet water closets (expressly prohibited by § 402.6.3).
- Failing to secure the carrier fitting to structure for wall‑mounted water closets (carrier must be securely attached; § 402.6).
Worked example — applying the rule (concrete scenario)
Scenario: You are installing a floor‑mounted, back‑outlet water closet on a finished bathroom floor.
- Verify the finished floor is complete and plan to set the closet flange bottom on the top of the finished floor as required by § 402.6.
- Use an approved closet ring (for example, PVC or copper alloy) that is approximately 7 inches in diameter and presents a 1‑1/2 inch face for the gasket/seal (per § 402.6.1).
- Ensure the wall and floor provide a flat mounting surface not less than 5 inches to the right and left of the fixture outlet centerline and that the bowl will be set level with a 90° angle at the outlet centerline, per § 402.6.3.
- Fasten the closet flange to the wall mounting surface and the fixture to the flange and floor using copper or copper‑alloy screws/bolts of a size and number sufficient to properly support the fixture; confirm fastener selection with the fixture manufacturer and local AHJ as required by § 402.6.2.
- Do not use an offset or reducing flange with this back‑outlet fixture (prohibited by § 402.6.3).
This sequence follows the CPC requirements and avoids common failures (improper flange height, inadequate fasteners, prohibited flange types).
Related provisions
- § 402.1 — Fixtures must allow access for repairs and cleaning.
- § 402.2 — Joints where fixture contacts wall or floor must be watertight.
- § 402.5 — Fixture setting and clearances (layout, clearances from walls/obstructions).
- § 402.7 — Supply lines and fittings must prevent backflow (see Chapter 6).
- § 402.8 / § 402.9 — Install fixtures per manufacturer’s instructions; do not compromise backflow prevention.
- § 402.10 — Accessibility for concealed slip‑joint connections (access panels).
Code references
Grounded in the retrieved California Plumbing Code — click a citation to read the verbatim passage:
CPC § 402.4 High relevance — show source text
402.4 Wall-Hung Fixtures. Wall-hung fixtures shall be rigidly supported by metal supporting members so that no strain is transmitted to the connections. Floor-affixed supports for off-the-floor plumbing fixtures for public use shall comply with ASME A112.6.1M. Framing-affixed supports for off-thefloor water closets with concealed tanks shall comply with ASME A112.6.2. Flush tanks and similar appurtenances shall be secured by approved non-corrosive screws or bolts.
402.5 Setting. Fixtures shall be set level and in proper alignment with reference to adjacent walls. No water closet or bidet shall be set closer than 15 inches (381 mm) from its center to a side wall or obstruction or closer than 30 inches (762 mm) center to center to a similar fixture. The clear space in front of a water closet, lavatory, or bidet shall be not less than 24 inches (610 mm). No urinal shall be set closer than 12 inches (305 mm) from its center to a side wall or partition or closer than 24 inches (610 mm) center to center.
Exception: The installation of paper dispensers or accessibility grab bars shall not be considered obstructions.
402.6 Flanged Fixture Connections. Fixture connections between drainage pipes and water closets, floor outlet service sinks and urinals shall be made using an approved copper alloy, hard lead, ABS, PVC, or iron flanges caulked, soldered, solvent cemented; rubber compression gaskets; or screwed to the drainage pipe. The connection shall be bolted with an approved gasket, washer, or setting compound between the fixture and the connection. The bottom of the flange shall be set on the top of the finished floor.
Wall-mounted water closet fixtures shall be securely bolted to an approved carrier fitting. The approved carrier fitting shall be securely attached to the structure. The connecting pipe between the carrier fitting and the fixture shall be an approved material and designed to accommodate an adequately sized gasket. Gasket material shall be neoprene, felt, or similar approved types.
402.6.1 Closet Rings (Closet Flanges). Closet rings (closet flanges) for water closets or similar fixtures shall be of an approved type and shall be copper alloy, copper, hard lead, cast-iron, galvanized malleable iron,
2025 CALIFORNIA PLUMBING CODE 59
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
PLUMBING FIXTURES AND FIXTURE FITTINGS
ABS, PVC, or other approved materials. Closet rings (closet flanges) shall be approximately 7 inches (178 mm) in diameter and, where installed, shall, together with the soil pipe, present a 1 [1] ⁄ 2 inch (38 mm) wide flange or face to receive the fixture gasket or closet seal.
Caulked-on closet rings (closet flanges) shall be not less than [1] ⁄ 4 of an inch (6.4 mm) thick and not less than 2 inches (51 mm) in overall depth.
Closet rings (closet flanges) shall be burned or soldered to lead bends or stubs, shall be caulked to cast-iron soil pipe, shall be solvent cemented to ABS and PVC, and shall be screwed or fastened in an approved manner to other materials.
CPC § 1101.1 High relevance — show source text
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. See Civil Code Section 1101.1, et seq., for the def- inition of a noncompliant plumbing fixture, types of residential buildings affected and other important enactment dates. Note 3: [OSHPD 1, 2, 3 & 4] Also refer to Title 20, Cali- fornia Code of Regulations, Division 2, Chapter 4, Article 4, Section 1605.3 (i). Note 4: Appliance Efficiency Regulations – Water Effi- ciency. [CEC] Where California law in Title 20 Sections 1601 et seq. applying to water-using appliances sold or offered for sale within the state specifies a lower maximum flow rate than specified in Section 407.2, 408.3, or 411.2, the lower maximum flow rate shall be required.
402.0 Installation.
402.1 Cleaning. Plumbing fixtures shall be installed in a manner to afford easy access for repairs and cleaning. Pipes from fixtures shall be run to the nearest wall.
402.2 Joints. Where a fixture comes in contact with the wall or floor, the joint between the fixture and the wall or floor shall be made watertight.
402.3 Securing Fixtures. Floor-outlet or floor-mounted fixtures shall be rigidly secured to the drainage connection and to the floor, where so designed, by screws or bolts of copper, copper alloy, or other equally corrosion-resistant material.
402.4 Wall-Hung Fixtures. Wall-hung fixtures shall be rigidly supported by metal supporting members so that no strain is transmitted to the connections. Floor-affixed supports for off-the-floor plumbing fixtures for public use shall comply with ASME A112.6.1M. Framing-affixed supports for off-thefloor water closets with concealed tanks shall comply with ASME A112.6.2. Flush tanks and similar appurtenances shall be secured by approved non-corrosive screws or bolts.
402.5 Setting. Fixtures shall be set level and in proper alignment with reference to adjacent walls. No water closet or bidet shall be set closer than 15 inches (381 mm) from its center to a side wall or obstruction or closer than 30 inches (762 mm) center to center to a similar fixture. The clear space in front of a water closet, lavatory, or bidet shall be not less than 24 inches (610 mm). No urinal shall be set closer than 12 inches (305 mm) from its center to a side wall or partition or closer than 24 inches (610 mm) center to center.
Exception: The installation of paper dispensers or accessibility grab bars shall not be considered obstructions.
402.6 Flanged Fixture Connections. Fixture connections between drainage pipes and water closets, floor outlet service sinks and urinals shall be made using an approved copper alloy, hard lead, ABS, PVC, or iron flanges caulked, soldered, solvent cemented; rubber compression gaskets; or screwed to the drainage pipe. The connection shall be bolted with an approved gasket, washer, or setting compound between the fixture and the connection. The bottom of the flange shall be set on the top of the finished floor.
CPC § 402.6.1 High relevance — show source text
Wall-mounted water closet fixtures shall be securely bolted to an approved carrier fitting. The approved carrier fitting shall be securely attached to the structure. The connecting pipe between the carrier fitting and the fixture shall be an approved material and designed to accommodate an adequately sized gasket. Gasket material shall be neoprene, felt, or similar approved types.
402.6.1 Closet Rings (Closet Flanges). Closet rings (closet flanges) for water closets or similar fixtures shall be of an approved type and shall be copper alloy, copper, hard lead, cast-iron, galvanized malleable iron,
2025 CALIFORNIA PLUMBING CODE 59
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
PLUMBING FIXTURES AND FIXTURE FITTINGS
ABS, PVC, or other approved materials. Closet rings (closet flanges) shall be approximately 7 inches (178 mm) in diameter and, where installed, shall, together with the soil pipe, present a 1 [1] ⁄ 2 inch (38 mm) wide flange or face to receive the fixture gasket or closet seal.
Caulked-on closet rings (closet flanges) shall be not less than [1] ⁄ 4 of an inch (6.4 mm) thick and not less than 2 inches (51 mm) in overall depth.
Closet rings (closet flanges) shall be burned or soldered to lead bends or stubs, shall be caulked to cast-iron soil pipe, shall be solvent cemented to ABS and PVC, and shall be screwed or fastened in an approved manner to other materials.
Closet bends or stubs shall be cut-off to present a smooth surface even with the top of the closet ring before the rough inspection is called.
Closet rings (closet flanges) shall be adequately designed and secured to support fixtures connected thereto.
402.6.2 Securing Closet Flanges. Closet screws, bolts, washers, and similar fasteners shall be of copper alloy, copper, or other listed equally corrosion-resistant materials. Screws and bolts shall be of a size and number to properly support the fixture installed. 402.6.3 Securing Floor-Mounted, Back-Outlet Water Closet Bowls. Floor-mounted, back-outlet water closet bowls shall be set level with an angle of 90 degrees (1.57 rad) between the floor and wall at the centerline of the fixture outlet. The floor and wall shall have a flat mounting surface not less than 5 inches (127 mm) to the right and left of the fixture outlet centerline. The closet flange shall be secured to the wall mounting surface. Offset, eccentric, or reducing closet flanges shall not be permitted with these fixtures.
The fixture shall be secured to the wall outlet flange or drainage connection and the floor by corrosion-resistant screws or bolts.
402.7 Supply Fittings. The supply lines and fittings for every plumbing fixture shall be so installed as to prevent backflow in accordance with Chapter 6.
402.8 Installation. Fixtures shall be installed in accordance
with the manufacturer’s installation instructions.
402.9 Design and Installation of Plumbing Fixtures. Plumbing fixtures shall be installed in accordance with the manufacturer’s installation instructions. The means of backflow prevention shall not be compromised by the designated fixture fitting mounting surface. **402.10 Slip Joint Connections.
CPC § 402.6.2 High relevance — show source text
Closet rings (closet flanges) shall be adequately designed and secured to support fixtures connected thereto.
402.6.2 Securing Closet Flanges. Closet screws, bolts, washers, and similar fasteners shall be of copper alloy, copper, or other listed equally corrosion-resistant materials. Screws and bolts shall be of a size and number to properly support the fixture installed. 402.6.3 Securing Floor-Mounted, Back-Outlet Water Closet Bowls. Floor-mounted, back-outlet water closet bowls shall be set level with an angle of 90 degrees (1.57 rad) between the floor and wall at the centerline of the fixture outlet. The floor and wall shall have a flat mounting surface not less than 5 inches (127 mm) to the right and left of the fixture outlet centerline. The closet flange shall be secured to the wall mounting surface. Offset, eccentric, or reducing closet flanges shall not be permitted with these fixtures.
The fixture shall be secured to the wall outlet flange or drainage connection and the floor by corrosion-resistant screws or bolts.
402.7 Supply Fittings. The supply lines and fittings for every plumbing fixture shall be so installed as to prevent backflow in accordance with Chapter 6.
402.8 Installation. Fixtures shall be installed in accordance
with the manufacturer’s installation instructions.
402.9 Design and Installation of Plumbing Fixtures. Plumbing fixtures shall be installed in accordance with the manufacturer’s installation instructions. The means of backflow prevention shall not be compromised by the designated fixture fitting mounting surface. 402.10 Slip Joint Connections. Fixtures having concealed slip joint connections shall be provided with an access panel or utility space not less than 12 inches (305 mm) in its least dimension and so arranged without obstructions as to make such connections accessible for inspection and repair. 402.11 Future Fixtures. Where provisions are made for the future installation of fixtures, those provided for shall be considered in determining the required sizes of the drain and water supply piping. Construction for future installations shall be terminated with a plugged fitting or fittings. Where the plugged
fitting is at the point where the trap of a fixture is installed, the plumbing system for such fixture shall be complete and be in accordance with the plumbing requirements of this code.
403.0 Accessible Plumbing Facilities. 403.1 General. Where accessible facilities are required in applicable building regulations, the facilities shall be installed in accordance with those regulations. [HCD 1-AC] For spe- cific requirements regarding accommodations for persons with disabilities, see Chapter 11A of the California Building Code. 403.2 Fixtures and Fixture Fittings for Persons with Disabilities. Plumbing fixtures and fixture fittings for persons with disabilities shall be in accordance with ICC A117.1 and the applicable standards referenced in Chapter 4. [HCD 1-AC] Specific requirements regarding accommodations for persons with disabilities are contained in Chapter 11A of the California Building Code. 403.3 Exposed Pipes and Surfaces. Water supply and drainpipes under accessible lavatories and sinks shall be insulated or otherwise be configured to protect against contact. Protectors, insulators, or both shall comply with ASME A112.18.9 or ASTM C1822.
CPC § 11A-9 High relevance — show source text
2. Clear space at fixtures. Doors shall not swing into the clear floor space required for any fixture. Required clear floor space, clearance at fixtures, and turning space shall be permitted to overlap.
3. Accessible water closet compartment. Accessible water closet compartments shall be 60 inches (1524 mm) wide minimum measured perpendicular to the side wall, 56 inches (1422 mm) deep minimum for wall hung water closets and 59 inches (1499 mm) deep minimum for floor mounted water closets measured perpendicular to the rear wall. (See Figure 11A-9A(c).)
Water closet fixtures located in accessible water closet compartments shall be positioned with a wall or partition to the rear and to one side. The centerline of the water closet shall be 17 inches (432 mm) minimum to 18 inches (457 mm) maxi- mum from the side wall or partition.
In ambulatory accessible toilet compartments specified in Item 6 of this section, the water closet shall be 17 inches (432 mm) minimum and 19 inches (483 mm) maximum from the side wall or partition. (See Figure 11A-9A (d).)
Clearance around a water closet shall be 60 inches (1524 mm) minimum measured perpendicular from the side wall and 56 inches (1422 mm) minimum measured perpendicular from the rear wall. The required clearance around the water closet shall be permitted to overlap the water closet, associated grab bars, dispensers, sanitary napkin disposal units, coat hooks, shelves, accessible routes, clear floor space and clearances required at other fixtures, and the turning space. No other fixtures or obstructions shall be located within the required water closet clearance.
A minimum 48 inches (1219 mm) deep and 60 inches (1524 mm) wide clear maneuvering space shall be provided in front of the water closet if the compartment has an end-opening door (facing the water closet). A minimum 60 inches (1524 mm) deep and 60 inches (1524 mm) wide clear maneuvering space shall be provided in a compartment with the door located at the side. (See Figure 11A-9A.)
4. Grab bars. Grab bars shall be provided on the side wall closest to the water closet and on the rear wall. Grab bars shall comply with this section and Section 1127A.4.
The side wall grab bar shall be 42 inches (1067 mm) long minimum, located 12 inches (305 mm) maximum from the rear wall and extend 54 inches (1372 mm) minimum from the rear wall. The front end of the side grab bar shall be positioned 24 inches (610 mm) minimum in front of the water closet.
The rear wall grab bar shall be 36 inches (914 mm) long minimum and extend from the centerline of the water closet 12 inches (305 mm) minimum on one side and 24 inches (610 mm) minimum on the other side.
Exceptions:
1. The rear grab bar shall be permitted to be 24 inches (610 mm) long minimum, centered on the water closet, when wall space does not permit a length of 36 inches (914 mm) minimum due to the location of a recessed fixture adja- cent to the water closet.
2025 CALIFORNIA BUILDING CODE 11A-23
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
HOUSING ACCESSIBILITY
CPC § 401.2 High relevance — show source text
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. See Civil Code Section 1101.1, et seq., for the def- inition of a noncompliant plumbing fixture, types of residential buildings affected and other important enactment dates. Note 3: [OSHPD 1, 2, 3 & 4] Also refer to Title 20, Cali- fornia Code of Regulations, Division 2, Chapter 4, Article 4, Section 1605.3 (i). Note 4: Appliance Efficiency Regulations – Water Effi- ciency. [CEC] Where California law in Title 20 Sections 1601 et seq. applying to water-using appliances sold or offered for sale within the state specifies a lower maximum flow rate than specified in Section 407.2, 408.3, or 411.2, the lower maximum flow rate shall be required.
402.0 Installation.
402.1 Cleaning. Plumbing fixtures shall be installed in a manner to afford easy access for repairs and cleaning. Pipes from fixtures shall be run to the nearest wall.
402.2 Joints. Where a fixture comes in contact with the wall or floor, the joint between the fixture and the wall or floor shall be made watertight.
402.3 Securing Fixtures. Floor-outlet or floor-mounted fixtures shall be rigidly secured to the drainage connection and to the floor, where so designed, by screws or bolts of copper, copper alloy, or other equally corrosion-resistant material.
CPC § 5.4.7 Medium relevance — show source text
Where the bar used is Grade 60 and the size specified in the table, the actual spacing in the wall shall not exceed a whole-
number multiple of 12 inches such as, 12, 24, 36 and 48, that is less than or equal to the tabulated spacing. Vertical reinforcement with a yield strength of less than 60,000 psi
or bars of a different size than specified in the table are permitted in accordance with Section R608.5.4.7 and Table R608.5.4(2).
h. See Table R608.3 for minimum core dimensions and maximum spacing of horizontal and vertical cores.
i. “Top” means gravity load from roof or floor construction bears on top of wall. “Side” means gravity load from floor construction is transferred to wall from a wood ledger or
cold-formed steel track bolted to side of wall. For nonload-bearing wall and where floor framing members span parallel to the wall, use of the “Top” bearing condition is
permitted.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s, 1 pound per square inch = 6.895 kPa, 1 square foot = 0.0929 m2.
a. Table is based on ASCE 7 components and cladding wind pressures for an enclosed building using a mean roof height of 35 feet, interior wall area 4, an effective wind area of
10 square feet, topographic factor,Kzt, equal to 1.0, and Risk Category II.
b. Table is based on concrete with a minimum specified compressive strength of 2,500 psi.
c. See Section R608.6.5 for location of reinforcement in wall.
d. Deflection criterion is_L_/240, where_L_ is the unsupported height of the wall in inches.
e. Interpolation is not permitted.
f. Where No. 4 reinforcing bars at a spacing of 48 inches are specified in the table as indicated by shaded cells, use of bars with a minimum yield strength of 40,000 psi or 60,000
psi is permitted.
g. Other than for No. 4 bars spaced at 48 inches on center, table values are based on reinforcing bars with a minimum yield strength of 60,000 psi. Maximum spacings shown are
the values calculated for the specified bar size. Where the bar used is Grade 60 and the size specified in the table, the actual spacing in the wall shall not exceed a whole-
number multiple of 12 inches such as, 12, 24, 36 and 48, that is less than or equal to the tabulated spacing. Vertical reinforcement with a yield strength of less than 60,000 psi
or bars of a different size than specified in the table are permitted in accordance with Section R608.5.4.7 and Table R608.5.4(2).
h. See Table R608.3 for minimum core dimensions and maximum spacing of horizontal and vertical cores.
i. “Top” means gravity load from roof or floor construction bears on top of wall. “Side” means gravity load from floor construction is transferred to wall from a wood ledger or
cold-formed steel track bolted to side of wall. For nonload-bearing wall and where floor framing members span parallel to the wall, use of the “Top” bearing condition is
permitted.|2025 CALIFORNIA RESIDENTIAL CODE 6-121
CPC § 910.7 Medium relevance — show source text
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
2025 CALIFORNIA PLUMBING CODE 191
), 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.
911.2 Circuit Vent Size and Connection. The circuit vent size shall be in accordance with Table 703.2 according to the number of circuit vented fixtures connected to the horizontal branch but shall be not less than 2 inches (50 mm) in diameter. The vent shall connect to the horizontal branch on the vertical between the two most upstream trap arms. The circuit vent pipe shall not receive the discharge of soil or
waste.
911.2.1 Multiple Circuit Vents. When multiple circuit vents are interconnected according to Section 911.4.1, each individual circuit vent shall be sized according to Section 911.2. The vent pipe connecting each circuit vent shall be sized according to Table 703.2.
911.3 Relief Vent. A 2 inch (50 mm) relief vent shall be provided for circuit-vented horizontal branches receiving the discharge of four or more water closets when connecting to a drainage stack that receives the discharge of soil or waste from upper horizontal branches.
911.3.1 Connection and Installation. The relief vent
shall connect to the horizontal branch between the stack and the most downstream trap arm of the circuit vent. The relief vent shall be installed on the vertical to the
horizontal branch.
911.3.2 Fixture Drain. The relief vent is permitted to serve as a fixture drain. Fixtures discharging to a relief vent shall be one or two fixture unit fixtures but shall not
exceed a total of 4 fixture units.
911.4 Slope and Size of Horizontal Branch. The vented section of the horizontal branch shall be uniformly sloped and not more than 1 inch per foot (83.3 mm/m). The entire length of the vented section of the horizontal branch shall be sized for the total drainage discharge to the branch according to Table 703.2.
CPC § 409.6.1 Medium relevance — show source text
1, 409.6.1| |ASME A112.19.12-2014
(R2019)|Wall Mounted, Pedestal Mounted, Adjustable, Elevating, Tilt-
ing, and Pivoting Lavatory, Sink, and Shampoo Bowl Carrier
Systems and Drain Waste Systems|Fixtures|407.1, 420.1| |ASME A112.19.14-2013
(R2018)|Six-Liter Water Closets Equipped with a Dual Flushing Device|Fixtures|411.2.1| |ASME A112.19.15-2012
(R2017)|Bathtubs/Whirlpool Bathtubs with Pressure Sealed Doors|Fixtures|409.1| |ASME A112.19.19-2016
(R2021)|Vitreous China Nonwater Urinals|Fixtures|412.1, 412.1.2| |ASSE 1002-2020/ASME
A112.1002-2020/CSA
B125.12-2020|Anti-Siphon Fill Valves for Water Closet Tanks|Backflow Protection|413.3, Table 603.2| |ASME A112.36.2M-1991
(R2017)|Cleanouts|DWV Components|Table 707.2, 707.4.1| |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 1037-2020/ASME
A112.1037-2020/CSA
B125.37-2020|Pressurized Flushing Devices for Plumbing Fixtures|Backflow Protection|413.2| |ASSE 1070-2020/ASME
A112.1070-2020/CSA
B125.70-2020|Water Temperature Limiting Devices|Valves|407.3(1), 409.4(1),
410.3(1), 417.7(1),
417.8| |ASME B1.20.1-2013
(R2018)|Pipe Threads, General Purpose (Inch)|Joints|605.1.5, 605.2.3,
605.5.2, 605.12.3,
705.1.3, 705.3.4,
705.4.2, 705.6.3,
1208.5.8, 1322.5(2)| |ASME B16.1-2020|Gray Iron Pipe Flanges and Flanged Fittings: Classes 25, 125,
and 250|Fittings|1208.5.11.1|336 2025 CALIFORNIA PLUMBING CODE
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
REFERENCED STANDARDS
TABLE 1701.1 (continued) REFERENCED STANDARDS
STANDARD NUMBER STANDARD TITLE APPLICATION REFERENCED
SECTIONASME B16.3-2021 Malleable Iron Threaded Fittings: Classes 150 and 300 Fittings Table 604.1,
Table 701.CPC § 1.48 Medium relevance — show source text
16| |4 × 4 ×1/4 wall thickness|120|1.48|2.59|3.50|4.30| |6 double extra strong
0.864 wall thickness|80|0.59|1.46|2.23|2.92| |6 double extra strong
0.864 wall thickness|100|0.73|1.71|2.54|3.29| |6 double extra strong
0.864 wall thickness|110|0.80|1.82|2.69|3.47| |6 double extra strong
0.864 wall thickness|120|0.86|1.93|2.83|3.63| |6 extra strong 0.432
wall thickness|80|0.94|1.90|2.70|3.42| |6 extra strong 0.432
wall thickness|100|1.10|2.13|2.98|3.74| |6 extra strong 0.432
wall thickness|110|1.17|2.22|3.11|3.89| |6 extra strong 0.432
wall thickness|120|1.24|2.34|3.24|4.04| |6 standard 0.280
wall thickness|80|1.14|2.12|2.93|3.64| |6 standard 0.280
wall thickness|100|1.29|2.33|3.19|3.94| |6 standard 0.280
wall thickness|110|1.36|2.43|3.31|4.08| |6 standard 0.280
wall thickness|120|1.42|2.53|3.43|4.22| |5 double extra strong
0.750 wall thickness|80|0.70|1.61|2.40|3.12| |5 double extra strong
0.750 wall thickness|100|0.85|1.86|2.71|3.47| |5 double extra strong
0.750 wall thickness|110|0.91|1.97|2.85|3.63| |5 double extra strong
0.750 wall thickness|120|0.98|2.02|2.99|3.79| |5 extra strong 0.375
wall thickness|80|1.04|2.01|2.83|3.54| |5 extra strong 0.375
wall thickness|100|1.19|2.23|3.09|3.85| |5 extra strong 0.375
wall thickness|110|1.26|2.34|3.22|4.00| |5 extra strong 0.375
wall thickness|20|1.32|2.44|3.34|4.14| |5 standard 0.258
wall thickness|80|1.20|2.19|3.00|3.72| |5 standard 0.258
wall thickness|100|1.34|2.39|3.25|4.00| |5 standard 0.258
wall thickness|110|1.41|2.49|3.37|4.14| |5 standard 0.258
wall thickness|120|1.47|2.58|3.49|4.28| |4 double extra strong
0.674 wall thickness|80|0.80|1.75|2.56|3.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
2025 CALIFORNIA PLUMBING CODE 191
), 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 § 6.1507 Medium relevance — show source text
LIFT = Entering Condenser Water Temperature (°F) – Leaving Chilled Water Temperature (°F)
2. Condenser DT = Leaving Condenser Water Temperature (°F) – Entering Condenser Water Temperature (°F)
Kadj = 6.1507 – 0.30244(×) + 0.0062692(×)2 – 0.000045595(×)3
where× = Condenser DT + LIFT
COPadj = Kadj * COPstd|1. LIFT = Entering Condenser Water Temperature (°F) – Leaving Chilled Water Temperature (°F)
2. Condenser DT = Leaving Condenser Water Temperature (°F) – Entering Condenser Water Temperature (°F)
Kadj = 6.1507 – 0.30244(×) + 0.0062692(×)2 – 0.000045595(×)3
where× = Condenser DT + LIFT
COPadj = Kadj * COPstd|1. LIFT = Entering Condenser Water Temperature (°F) – Leaving Chilled Water Temperature (°F)
2. Condenser DT = Leaving Condenser Water Temperature (°F) – Entering Condenser Water Temperature (°F)
Kadj = 6.1507 – 0.30244(×) + 0.0062692(×)2 – 0.000045595(×)3
where× = Condenser DT + LIFT
COPadj = Kadj * COPstd|1. LIFT = Entering Condenser Water Temperature (°F) – Leaving Chilled Water Temperature (°F)
2. Condenser DT = Leaving Condenser Water Temperature (°F) – Entering Condenser Water Temperature (°F)
Kadj = 6.1507 – 0.30244(×) + 0.0062692(×)2 – 0.000045595(×)3
where× = Condenser DT + LIFT
COPadj = Kadj * COPstd|1. LIFT = Entering Condenser Water Temperature (°F) – Leaving Chilled Water Temperature (°F)
2. Condenser DT = Leaving Condenser Water Temperature (°F) – Entering Condenser Water Temperature (°F)
Kadj = 6.1507 – 0.30244(×) + 0.0062692(×)2 – 0.000045595(×)3
where× = Condenser DT + LIFT
COPadj = Kadj * COPstd|1. LIFT = Entering Condenser Water Temperature (°F) – Leaving Chilled Water Temperature (°F)
2. Condenser DT = Leaving Condenser Water Temperature (°F) – Entering Condenser Water Temperature (°F)
Kadj = 6.1507 – 0.30244(×) + 0.0062692(×)2 – 0.000045595(×)3
where× = Condenser DT + LIFT
COPadj = Kadj * COPstd|A6.207.1.2 Controls for heat pumps with supplementary electric resistance heaters. Heat pumps with supplementary electric resistance heaters shall have controls:
A6.207.1.2.1 That prevent supplementary heater operation when the heating load can be met by the heat pump alone; and
Frequently asked questions
What material must closet flange screws/bolts be made of?
They must be copper, copper alloy, or other equally corrosion‑resistant materials as required by § 402.6.2.
Can I use an offset or reducing closet flange for a back‑outlet floor‑mounted toilet?
No. Offset, eccentric, or reducing closet flanges are not permitted with floor‑mounted, back‑outlet water closet bowls per § 402.6.3.
Where should the bottom of the closet flange be located?
The bottom of the flange shall be set on the top of the finished floor, per § 402.6.
Are there prescribed bolt counts or sizes for closet flange fasteners?
The CPC requires screws/bolts be of corrosion‑resistant material and of a size and number to properly support the fixture; the exact size/number should follow the manufacturer’s instructions and the AHJ’s approval (see § 402.6.2).
Do wall‑hung toilets transmit load to the trap or piping?
No. Wall‑hung fixtures must be rigidly supported by metal supporting members so that no strain is transmitted to the connections (see § 402.4).
More in California Plumbing Code
- Administration
- Definitions
- General Regulations
- Plumbing Fixtures and Fixture Fittings
- Water Heaters
- Water Supply and Distribution
- Sanitary Drainage (Drain, Waste, and Vent)
- Indirect Wastes
- Vents
- Traps and Interceptors
- Storm Drainage
- Fuel Gas Piping
- Health Care Facilities — Medical Gas and Medical Vacuum Systems
- Alternate Water Sources and Nonpotable Rainwater Catchment Systems
Ask about the CPC
Get cited, plain-English answers on the California Plumbing Code for your project — any code section, any scenario.
Start Free Trial