How to Tile a Premade Plastic Shower Pan
When remodeling a bathroom, one thing to be replaced is often the shower, bathtub, or shower/bath combination. If you have a shower, you'll need to make a choice about shower pans. Do you install a pre-fabricated shower stall, which offers the advantage of a premade shower pan, or a tiled shower with a built-from-scratch shower pan?
Instead of choosing between one or the other, it's possible to have a combination: Tile the walls and still install a synthetic shower pan. This gives you the beauty of the tiled walls and the easy installation of a prefabricated pan. For do-it-yourselfers, using a premade shower pan with tile is easier and far more foolproof than the traditional tilers' method of forming a shower base from scratch.
What a Tile-Over Shower Pan Is
A tile-over shower pan is a shower pan that is designed to accept tile and can do so because it is heavier and sturdier than a normal pan. This allows the pan to withstand the weight of most users without cracking the grout or tile.
In a typical installation, the shower pan is set into a bed of mortar to level it and secure it to the subfloor. Next, the walls are covered with cement board and are sealed to the pan with silicone caulk or with a special flashing followed by caulk.
The tiles adhere to the base either with a conventional modified thinset or with an epoxy adhesive supplied by the shower pan manufacturer. You cannot tile over standard polymer or fiberglass shower pans because they flex too much and will eventually crack the tile grout and possibly even the tile itself.
Pre-sloped: no need to slope and incline the tile
Possibility of leaking greatly reduced
Reduces the amount of work
Considerably more expensive than building a mortar-base tiled shower pan
Comes only in a limited number of sizes
What You'll Need
Equipment / Tools
- 1 notched trowel
- 1 bucket
- 1 wet tile saw
- 1 rail tile cutter
- 1 rubber tiling float
- 1 tile-ready shower pan
- 2 boxes tile
- 1 subfloor waterproofing
- 1 bag mortar
- 1 bag grout
- 1 grout sealer
Instructions for Tiling a Premade Plastic Shower Pan
The standard installation of a tile-over polyurethane shower pan starts with a framed-in shower alcove that is sized for the shower pan. If the subfloor is wood, it should receive a layer of cement board to protect the wood from the mortar bed under the pan.
If there is access to the drain connection below the shower, the subfloor simply needs a hole for the shower pan drain assembly to fit through. The final drain hookup can be made after the shower is completed. The below guide is an overview, not a step-by-step how-to.
If there is no access below, the drain must be stubbed out to the proper height below the subfloor surface, and the shower pan drain assembly must be glued to the stubout when the pan is installed.
Frame the Shower
Frame the shower or shower/bathtub stall to the dimensions that come with the shower pan. Start by purchasing the shower pan (or referring to instructions) before framing out the enclosure.
Dry-Fit the Pan
Dry-fit the pan's drain with the subfloor's drain hole. Fit the shower pan itself into the shower or tub framed enclosure to check for proper fit.
Prepare the Drainpipe
Prepare the PVC or ABS drainpipe. It should extend upward far enough that it fits the target drain hole of the shower pan and it should be flush with the shower pan floor.
Apply the Waterproofing
Remove the shower pan. Apply the waterproofing to the subfloor. Waterproofing methods include a liquid membrane like Kemper Kemperol, tar paper, or a synthetic solid membrane such as Schluter Kerdi. Do not pour mortar directly onto a plywood subfloor. Always use an intervening waterproofing material.
Mix the Mortar
Mix up the mortar for the base of the shower pan.
Spread the Mortar Base on the Subfloor
With a trowel, spread the mortar across the subfloor to the depth specified by the shower pan manufacturer. The mortar should be spread evenly across the subfloor. Otherwise, pockets will develop in the mortar that will create hollowness below the shower pan.
Lay the Shower Pan in the Mortar Base
Carefully lay the shower pan on top of the mortar base. Apply enough pressure across the entire shower pan to evenly set the pan into the mortar. Avoid standing on the pan while the mortar is still wet.
Install the Cement Board on the Walls
After the shower pan mortar is solid enough to walk on, install the cement backer board on the walls of the shower. Seal all joints with silicone caulk.
Tile the Shower Pan
Tile the floor and the sides of the shower pan with a modified thinset. Use a notched trowel to regulate the flow of the thinset across the shower base.
Grout the Tile
After the thinset has cured solid, grout the tile.
Seal the Grout
Apply the grout sealer to the grout with a brush, sponge, or roller. Make sure to allow the sealer to dry completely before using the shower. You can easily test the grout sealer by applying a small amount of water to the grout. If the water beads up on the surface of the grout, the sealer is working properly.
When to Call a Professional
Hiring a licensed contractor to perform your installation is a wise investment when dealing with issues involving waterproofing. This step can potentially save you costly repairs later if done correctly.
If you do decide to build a tiled shower pan from scratch, it's often best to hire trained tile professionals. They have the knowledge and experience to create a built-up shower pan that will be durable, aesthetically pleasing, and most importantly, watertight.