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Earlier editions: 20222019

Chapter 9 — VENTS

903.1 Applicable Standards. Vent pipe and fittings shall

California Plumbing Code (Title 24, Part 5) · 2025 edition · updated 2026-09-10 · California

Italicized text is a California amendment to the model code, as printed in the official publication.

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.

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▸Contents — California Plumbing Code (Title 24, Part 5)
California Plumbing Code (Title 24, Part 5)
  1. Chapter 1 — GENERAL CODE PROVISIONS
  2. Chapter 2 — DEFINITIONS
  3. Chapter 3 — GENERAL REGULATIONS
  4. Chapter 4 — PLUMBING FIXTURES AND FIXTURE FITTINGS
  5. Chapter 5 — WATER HEATERS
  6. Chapter 6 — WATER SUPPLY AND DISTRIBUTION
  7. Chapter 7 — SANITARY DRAINAGE
  8. Chapter 8 — INDIRECT WASTES
  9. ▸Chapter 9 — VENTS
    Overview
    1. 901.1 Applicability. This chapter shall govern the materials,
    2. 901.2 Vents Required. Each plumbing fixture trap, except
    3. 901.3 Trap Seal Protection. The vent system shall be
    4. 902.1 Interceptor. Vent piping shall be permitted to be
    5. 902.2 Bars, Soda Fountains, and Counter. Traps serving sinks t…
    6. 903.1 Applicable Standards. Vent pipe and fittings shall
    7. 903.2 Use of Copper or Copper Alloy Tubing. Copper
    8. 903.3 Changes in Direction. Changes in the direction of
    9. 904.1 Size. The size of vent piping shall be determined from
    10. 904.2 Length. Not more than one-third of the total permitted l…
    11. 905.1 Grade. Vent and branch vent pipes shall be free from
    12. 905.2 Horizontal Drainage Pipe. Where vents connect to
    13. 905.3 Vent Pipe Rise. Unless prohibited by structural conditio…
    14. 905.4 Roof Termination. Vent pipes shall extend undiminished i…
    15. 905.5 Location of Opening. The vent pipe opening from
    16. 905.6 Common Vertical Pipe. Two fixtures shall be permitted to…
    17. 906.1 Roof Termination. Each vent pipe or stack shall
    18. 906.2 Clearance. Each vent shall terminate not less than
    19. 906.3 Use of Roof. Vent pipes shall be extended separately
    20. 906.4 Outdoor Installations. Vent pipes for outdoor
    21. 906.5 Joints. Joints at the roof around vent pipes shall be
    22. 906.6 Lead. (See Chapter 17) Sheet lead shall comply with
    23. 906.7 Frost or Snow Closure. Where frost or snow closure is li…
    24. 907.1 Drainage Stack. Each drainage stack that extends 10
    25. 907.2 Yoke Vent. The yoke vent connection to the vent stack
    26. 908.1 Vertical Wet Venting. Wet venting is limited to vertical…
    27. 908.2 Horizontal Wet Venting for a Bathroom Group.
    28. 909.1 General. Traps for island sinks and similar equipment
    29. 910.1 Where Permitted. Combination waste and vent systems shal…
    30. 910.2 Approval. Construction documents for each combination wa…
    31. 910.3 Vents. Each combination waste and vent system, as
    32. 910.4 Connections and Size. Branches serving traps
    33. 910.5 Vertical Waste Pipe. No vertical waste pipe shall be
    34. 910.6 Cleanouts. An accessible cleanout shall be installed
    35. 910.7 Fixtures. No water closet or urinal shall be installed
    36. 911.1 Circuit Vent Permitted. A maximum of eight flooroutlet w…
    37. 911.2 Circuit Vent Size and Connection. The circuit
    38. 911.3 Relief Vent. A 2 inch (50 mm) relief vent shall be provi…
    39. 911.4 Slope and Size of Horizontal Branch. The vented
    40. 911.5 Additional Fixtures. Fixtures, other than the circuitven…
    41. 912.1 General. The design and sizing of a vent system shall
    42. 912.2 Minimum Requirements. An engineered vent system shall pr…
  10. Chapter 10 — TRAPS AND INTERCEPTORS
  11. Chapter 11 — STORM DRAINAGE
  12. Chapter 12 — FUEL GAS PIPING
  13. Chapter 13 — HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICA…
  14. Chapter 14 — FIRESTOP PROTECTION
  15. Chapter 15 — ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS
  16. Chapter 16 — NONPOTABLE RAINWATER CATCHMENT SYSTEMS
  17. Chapter 17 — REFERENCED STANDARDS
  18. Appendix A — RECOMMENDED RULES FOR SIZING THE WATER SUPPLY SYS…
  19. Appendix B — EXPLANATORY NOTES ON COMBINATION WASTE AND VENT S…
  20. Appendix C — ALTERNATE PLUMBING SYSTEMS
  21. Appendix D — SIZING STORM WATER DRAINAGE SYSTEMS
  22. Appendix E — MANUFACTURED/MOBILE HOME PARKS AND RECREATIONAL V…
  23. Appendix F — FIREFIGHTER BREATHING AIR REPLENISHMENT SYSTEMS
  24. Appendix G — SIZING OF VENTING SYSTEMS
  25. Appendix H — PRIVATE SEWAGE DISPOSAL SYSTEMS
  26. Appendix I — INSTALLATION STANDARDS
  27. Appendix J — COMBINATION OF INDOOR AND OUTDOOR COMBUSTION AND …
  28. Appendix K — POTABLE RAINWATER CATCHMENT SYSTEMS
  29. Appendix L — SUSTAINABLE PRACTICES
  30. Appendix M — PEAK WATER DEMAND CALCULATOR
  31. Appendix N — IMPACT OF WATER TEMPERATURE ON THE POTENTIAL FOR …
  32. Appendix O — NON-SEWERED SANITATION SYSTEMS
  33. Appendix P — PROFESSIONAL QUALIFICATIONS
  34. Appendix Q — INDOOR HORTICULTURAL FACILITIES
  35. Appendix R — TINY HOUSES
  36. Appendix S — ONSITE STORMWATER TREATMENT SYSTEMS

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