CA Plumbing PrepC-36 License Exam Prep
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Trade Exam · Module 4

Accessible Fixtures and Specialty Piping Systems

Lesson 5 of 9~20 minFree previewCurrent as of September 2026Leer en español

What a plumber installs differently at an accessible fixture in California, taken from California Building Code Chapter 11B, with the California Plumbing Code rules that send you there: water closet centerline 17 to 18 inches from the side wall, seat 17 to 19 inches, grab bars 33 to 36 inches high, lavatory rim 34 inches maximum with 27 inch knee clearance and protected pipes, faucets you can work with one hand, and shower sizes, controls and thresholds. Then the specialty systems you must recognize: medical gas tubing, and the purple marking for graywater, recycled and rainwater piping.

Key Takeaways

  • CPC 403.1 to 403.3: where accessible facilities are required, install them per the applicable building regulations, and insulate or configure the supply and drain pipes under accessible lavatories and sinks to protect against contact. In California, public accommodations follow California Building Code Chapter 11B and housing follows Chapter 11A.
  • CBC 11B-604.2 and 11B-604.4: water closet centerline 17 to 18 inches from the side wall; seat 17 to 19 inches above the floor to the top of the seat.
  • CBC 11B-604.5 and 11B-609.4: side wall grab bar at least 42 inches long, rear wall bar at least 36 inches long, mounted horizontally 33 to 36 inches above the floor to the top of the gripping surface.
  • CBC 11B-606.3 and 11B-306.3: lavatory rim or counter 34 inches maximum; at an accessible lavatory the knee clearance is at least 27 inches high at a depth of 8 inches, rising to 29 inches at the front edge.
  • CBC 11B-309.4 and 11B-606.4: faucets work with one hand, without tight grasping, pinching or twisting of the wrist, at 5 pounds of force maximum; metering faucets stay open at least 10 seconds.
  • CBC 11B-608: a transfer shower is 36 by 36 inches inside; a standard roll-in shower is at least 30 by 60 inches with a 36 by 60 inch clearance beside it; thresholds are 1/2 inch maximum; the hand shower has a hose at least 59 inches long and delivers 120 F maximum.
  • CPC 1318.4: medical gas tube is hard-drawn seamless copper to ASTM B819, Type L (Type K above 185 psi for sizes over 3 inch).
  • CPC 601.3.3: graywater, recycled water, on-site treated water and rainwater piping is marked with a purple background and black uppercase "CAUTION ... DO NOT DRINK" lettering.

Why This Matters

Most accessibility dimensions are set by the building code, not the plumbing code, but the plumber is the one who roughs in the water closet, sets the lavatory, and installs the shower valve. If the rough-in is wrong, no amount of finish work fixes it.

The California Plumbing Code (CPC) points you to the right rules. CPC 403.1 says that where accessible facilities are required by the building regulations, they are installed in accordance with those regulations. The note at the start of CPC Chapter 4 names California Building Code (CBC) Chapter 11A (housing) and Chapter 11B (public buildings, public accommodations, commercial buildings and public housing). CPC 403.2 adds that fixtures and fittings for persons with disabilities follow ICC A117.1.

The dimensions below are California's, from CBC Chapter 11B. The federal ADA Standards are similar but not the same: the water closet centerline window and the roll-in shower clearance, for example, are different in California. For a California job and the C-36 exam, use the CBC numbers.

Pipes Under Accessible Lavatories and Sinks

CPC 403.3: water supply and drain pipes under accessible lavatories and sinks are insulated or otherwise configured to protect against contact. Protectors and insulators comply with ASME A112.18.9 or ASTM C1822. CBC 11B-606.5 says the same and adds that there can be no sharp or abrasive surfaces under lavatories and sinks.

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