CSLB C-36 Plumbing ContractorRough-in PlumbingMedium

A plumbing inspector is reviewing a rough-in installation for a new gas piping system in a commercial kitchen. The inspector observes that the gas piping is run through a concrete slab. What specific protection is required for gas piping installed within a concrete slab?

  1. ANo special protection is required if the pipe is Schedule 40 steel.
  2. BThe pipe must be painted with a corrosion-resistant coating.
  3. CThe pipe must be wrapped with approved electrical tape.
  4. DThe pipe must be encased in a continuous sleeve or conduit.
Show answer & explanation

Correct answer: D. The pipe must be encased in a continuous sleeve or conduit.

Gas piping installed in or under a concrete slab must be protected from corrosion and damage. The California Plumbing Code (CPC) mandates that such piping be encased in a continuous, approved sleeve or conduit that extends through the slab and is sealed at the ends to prevent water or concrete from contacting the pipe.

Why the other options are wrong

  • A. Even Schedule 40 steel pipe requires protection when embedded in concrete due to potential corrosion from the concrete and moisture.
  • B. While corrosion resistance is good, painting alone is not sufficient protection for gas piping within a slab.
  • C. Electrical tape is not an approved method for protecting gas piping within a concrete slab.

Gas Pipe Slab Protection

Measures required to protect gas piping when it is installed within or under concrete slabs from corrosion, physical damage, and leaks.

  • Prevents corrosion from concrete.
  • Protects against damage from slab movement.
  • Typically involves sleeving or conduit.

Memory trick: Slab Gas needs a Sleeve: Safe, Sealed, Secured.

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