PVC Shower Pan Liner. An economical, flexible liner designed to provide a waterproof seal to tile shower bases and for other concealed waterproofing applications. It is made of abrasion-resistant PVC material for long-lasting use, and is marked on the back in 6-inch increments to allow for easy measuring and trimming. This kit also includes two Oatey PVC Dam Corners, preformed, with flexible corners designed to seal the junction of the curb and door jamb.