Most of the bathroom shower remodel work we do include replacing a failed shower pan. “Failed” means that water is seeping through cracks in the shower floor or corners causing water damage (mold) — resulting in a smell that won’t go away or dis-colorization that can’t be removed. The following is an anatomy of a typical shower —
- Subfloor — For a 2nd floor shower or peer-and-beam home, this is typically 3/4″ plywood (or greater) to support the floor structure of the shower.
- Waterproof Composite — For 2nd floor and peer-and-beam homes, we install a Hardie-Backer material to keep either the mortar or water damaging the subfloor. For concrete foundations, this is typically not needed.
- Liner — The liner material is ether polyvinyl chloride (PVC) or chlorinated polyethylene (CPE). This liners are very difficult to puncture, but precautions are always taken to protect.
- Mortar Bed — This is a hard surface which will be sloped towards the drain to insure proper water flow. It also provides the backing for the tile. It should provide enough space below the top of the drain for tiles to be installed flush with the top.
- Thinset — this is the adhesive for the tile.
- Tile — ranging from 1/4 to 3/8″ thick, the tiles should be no larger than 4×4″ to ensure adequate traction while wet. The grout lines and the tile surface (friction coefficient) determines the overall traction of the surface.
- Drain — Interestingly enough, the drain is more complex than you would think.
- The base is the portion that connects to the drain system of your home.
- The liner coupler is just that, it connects the liner to the drain assembly to ensure that no any water that may seep from the shower walls / floor is directed to the drain … not to the foundation of sub-floor.
- The adjustable top screws into the base — it is adjustable to account for varying depths of mortar. The top leaks where it screws into the drain base … THAT’S RIGHT! … it leaks. There are weep holes / slots that allows any water or moisture penetrating the mortar to drain. IMPORTANT — it is important not to have these weep holes clogged by the mortar bed during installation — place pea-gravel or sand these areas to avoid clogs.
The shower pan installation approach is shown in the following video. Please note that the demonstrated installation is for either a 2nd floor or peer and beam home. Installations on concrete foundations differs slightly.