Shower Pan Liner

Category: infrastructure

An impervious waterproof membrane installed beneath a shower floor mortar bed to channel subsurface water to the weep holes.

Commonly composed of thick polyvinyl chloride (PVC) or chlorinated polyethylene (CPE) sheeting, the pan liner forms an absolute basin boundary beneath the sloped mortar bed. It must be folded cleanly into corners without punctures and run up the framing studs at least three inches above the finished curb line.

Common Examples

• The plumbing inspector filled the shower basin with water for twenty-four hours to verify the shower pan liner was completely leak-free.
• Nailing directly through the front face of a shower pan liner below the threshold line will completely ruin the waterproof envelope.