CSLB C-39 Roofing ContractorLow-Slope RoofingMedium
During a roof drainage inspection, a technician checks the strainer/dome on a primary roof drain. Per the California Plumbing Code, at minimum how many inches must the strainer extend above the roof surface immediately surrounding the drain?
- A4 inches
- B8 inches
- C2 inches
- D6 inches
Show answer & explanationAnswer & explanation
Correct answer: A. 4 inches
The California Plumbing Code requires roof drain strainers to extend a minimum of 4 inches above the surface of the roof immediately adjacent to the strainer, ensuring debris does not block water flow into the drain.
Why the other options are wrong
- B. 8 inches is well above the required minimum and not the code standard.
- C. 2 inches is below the code-required minimum height.
- D. 6 inches exceeds the code minimum requirement.
Roof Drain Strainer Height
The minimum height (4 inches) that a roof drain strainer dome must extend above the adjacent roof surface per the California Plumbing Code, to prevent debris blockage.
- CPC requires minimum 4-inch strainer height
- Prevents leaves/debris from clogging the drain
- Applies to primary roof drains on low-slope roofs
Memory trick: Four inches high keeps the leaves from the sky.