How to Install a Slab With Sewer Plumbing

Updated February 21, 2017

Unprotected from the natural shifting of a concrete slab, sewer plumbing pipes develop cracks that can result in costly repairs. Properly installing drain pipes through a slab requires basic hand tools and a few simple steps. You can avoid extensive renovation down the road.

Install under-slab and through-slab drain piping according to your blueprint's specifications. Bury pipes according to local building codes. Extend pipes above the level of the future slab, installing enough length to complete rough-in plumbing following the concrete pour.

Unroll the foam pipe wrap. Use duct tape to attach a loose end of the foam pipe wrap to an area of the drain pipe that will ultimately rest beneath the slab. Wrap the foam around the drain pipe, overlapping each layer, until the wrap extends beyond the future level of the slab's surface.

Secure the loose end of the foam pipe wrap to the pipe with duct tape.

Back-fill the trench and cover the under-slab portion of the drain pipe with soil. If properly wrapped, foam pipe wrap will extend both above and below the concrete slab. Proceed with the concrete pour.


Use a level and tape measure to double-check your pipe wrap's height before you backfill the trench.

Things You'll Need

  • Duct tape
  • Foam pipe wrap
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About the Author

Based in Hawaii, Shane Grey began writing professionally in 2004. He draws on his construction experience to write instructional home and garden articles. In addition to freelance work, Grey has held a position as an in-house copywriter for an online retailer. He holds a Bachelor of Arts in theater arts from Humboldt State University.