How to Replace a Shower Pan

A shower pan is the floor portion—or the base—of your shower. Designed with a slight slope to help water go down your drain, it may need replacing if it significantly moves, has visible leakage or large cracks, especially in the center.

In this video, This Old House plumbing and heating contractor Richard Trethewey explains how to replace a shower pan.

Steps to Replacing a Shower Pan:

1. Cut old acrylic shower surround with a reciprocating saw, and remove the surround.
2. Saw through drainpipe connected to old shower pan; remove shower pan.
3. Set new acrylic shower pan on floor and check its fit against the studs.
4. If necessary, build out studs with ½-inch plywood strips so pan clears any obstructions.
5. Mark shower pan’s drain hole onto the subfloor; also mark if pan overlaps the floor tile.
6. Remove shower pan.
7. If necessary, use hammer and cold chisel to chop out any tile that extends under the pan.
8. Attach the strainer to the drain hole in shower pan.
9. Vacuum the subfloor clean of all dust and debris.
10. Check floor with a 4-foot level; install shims to create level surface.
11. Set shower pan into place and check for level.
12. Secure shower pan to studs with galvanized screws; be sure to bore pilot holes first.
13. Dry fit new PVC trap to drainpipe; glue together the PVC parts using primer and cement.
14. Connect drainpipe to shower pan’s strainer with a compression gasket; use a rubber mallet to tap gasket and pipe flush with shower floor.
15. Install the screen to the strainer in the drain hole.
16. Complete the installation by covering the walls with backerboard, and then tile or other finished material.

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