Skip to content

Earlier editions: 20222019

Chapter 10 — TRAPS AND INTERCEPTORS

1003.1 General Requirements. Each trap, except for

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.

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

Notes: 1 Maintain 1 ⁄ 4 inch per foot slope (20.8 mm/m). 2 The developed length between the trap of a water closet or similar fixture (measured from the face of the closet flange to the inner edge of the vent) and its vent shall not exceed 6 feet (1829 mm). 3 Horizontally wet vented bathtubs, showers and similar fixtures shall be limited to a maximum of 6 feet (1829 mm) for 1½ inch (40 mm) fixture drains and 8 feet (2438 mm) for 2 inch (50 mm) fixture drains, maintaining ¼ inch per foot slope (20.8 mm/m).

Get a plain-English answer with a citation back to this text.

Ask AI about this code
Export this section
▸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
  10. ▸Chapter 10 — TRAPS AND INTERCEPTORS
    Overview
    1. 1001.1 Applicability. This chapter shall govern the materials,…
    2. 1001.2 Where Required. Each plumbing fixture shall be separate…
    3. 1002.1 Vent Pipes. Each plumbing fixture trap, except as
    4. 1002.2 Fixture Traps. Each fixture trap shall have a protectin…
    5. 1002.3 Change of Direction. A trap arm shall be permitted to c…
    6. 1002.4 Vent Pipe Opening. The vent pipe opening from
    7. 1003.1 General Requirements. Each trap, except for
    8. 1003.2 Slip Joint Fittings. A maximum of one approved
    9. 1003.3 Size. The size (nominal diameter) of a trap for a
    10. 1004.1 Prohibited. No form of trap that depends for its seal
    11. 1004.2 Movable Parts. Bladders, check valves or another
    12. 1005.1 General. Each fixture trap shall have a liquid seal of
    13. 1006.1 General. Floor drains shall connect into a trap so
    14. 1007.1 General. Floor drain or similar traps directly connecte…
    15. 1007.2 Trap Seal Primers. Potable water supply trap seal
    16. 1008.1 General. Building traps shall not be installed except
    17. 1009.1 Where Required. Interceptors (clarifiers) (including gr…
    18. 1009.2 Approval. The size, type, and location of each intercep…
    19. 1009.3 Design. Interceptors (clarifiers) for sand and similar …
    20. 1009.4 Relief Vent. Interceptors (clarifiers) shall be so
    21. 1009.5 Location. Each interceptor (clarifier) cover shall be
    22. 1009.6 Maintenance of Interceptors. Interceptors shall
    23. 1009.7 Discharge. The waste pipe from oil and sand interceptor…
    24. 1010.1 General. A fish, fowl, and animal slaughterhouse or
    25. 1010.2 Meat and Poultry Processing Plants. [AGR]
    26. 1010.3 Collection Centers and Facilities. [AGR] All
    27. 1010.4 Horse Meat and Pet Food Establishments.
    28. 1010.5 Draining and Plumbing. [AGR] There shall be
    29. 1011.1 General. A private or public wash rack or floor or
    30. 1012.1 General. Laundry equipment in commercial and
    31. 1013.1 General. Bottling plants shall discharge their process
    32. 1014.1 General. Where it is determined by the Authority
    33. 1014.2 Hydromechanical Grease Interceptors. Plumbing fixtures …
    34. 1014.3 Gravity Grease Interceptors. Required gravity
    35. 1015.1 Purpose. The purpose of this section is to provide
    36. 1015.2 Components, Materials, and Equipment. FOG
    37. 1015.3 Sizing and Installation. FOG disposal systems
    38. 1015.4 Performance. FOG disposal systems shall produce
    39. 1015.5 [OSHPD 1, 1R, 2, 3, 4 & 5] Grease interceptors
    40. 1015.6 [OSHPD 1, 1R, 2, 3, 4 & 5] Grease interceptors
    41. 1016.1 Discharge. Where the discharge of a fixture or drain
    42. 1016.2 Authority Having Jurisdiction. Sand interceptors
    43. 1016.3 Construction and Size. Sand interceptors shall be
    44. 1016.4 Separate Use. Sand and similar interceptors for
    45. 1017.1 Interceptors Required. Repair garages and gasoline stat…
    46. 1017.2 Interceptor Design Alternatives. Oil interceptors
    47. 1017.3 Interceptor Details. Oil and flammable liquid intercept…
    48. 1017.4 Design of Interceptors. Each manufactured interceptor t…
  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

GoCodebook provides public access, search, citation, multilingual explanation, and practical interpretation of legally adopted building regulations. It is not a substitute for the official ICC or California code publications.