CSLB C-36 Plumbing ContractorRough-in PlumbingMedium
A plumber is installing a new underground storm drainage system for a commercial building. The system includes a 6-inch diameter PVC pipe. What is the minimum required cover for this pipe under a landscape area not subject to vehicular traffic?
- A24 inches
- B6 inches
- C12 inches
- D18 inches
Show answer & explanationAnswer & explanation
Correct answer: C. 12 inches
According to the California Plumbing Code (CPC), underground drainage piping not subject to vehicular traffic, such as in a landscape area, must have a minimum cover of 12 inches. This protects the pipe from damage due to routine ground disturbances.
Why the other options are wrong
- A. 24 inches is often required under vehicular traffic areas or deeper for frost protection, but not the minimum for this condition.
- B. 6 inches is generally insufficient protection for underground piping and does not meet code.
- D. 18 inches is more than the minimum required for this specific scenario.
Underground Pipe Cover
The depth of earth or fill material above an underground pipe, specified by code to protect the pipe from damage.
- Protects pipes from crushing, freezing, and external forces.
- Varies based on pipe material, location, and traffic type.
- Minimums are set by plumbing codes (e.g., CPC).
Memory trick: Cover the pipe, keep it safe and sound, 12 inches from the top of the ground.