How to Tile a Plastic Sheet Shower Wall

Turn off the water supply to the shower using the supply valves in the access panel on the other side of the wall from which the shower pipes protrude. Turn on the faucet to empty any remaining water from the valves. Dry off the shower enclosure with a towel.

Cover the edges of any surfaces adjacent to the plastic shower wall with a strip of masking tape. Place a drop cloth over the shower base to prevent any debris from falling into the shower drain.

Remove all shower faucets and fixtures from the walls. Use a utility knife to cut through any caulking surrounding the fixtures' bases, then pull the caulking away with a putty knife. Use a Phillips screwdriver to remove any screws holding the fixtures in place, then pull the fixtures away from the wall, leaving only the protruding pipes.

Sand the plastic walls with a piece of medium-grit sandpaper attached to a sanding block, until you remove the glossy finish from the plastic. The finish can interfere with the tile adhesive. The sanding also creates a slight texture on which the adhesive can stick. Wipe the shower walls clean with a piece of cloth.

Mark the base guideline for the tiles by measuring 1/8 inch up the wall from the shower base and placing a horizontal line along the wall with a marker, using a straightedge as a guide. Make certain the straightedge is level by placing a carpenter’s level on top before marking your line. Measure the length of the wall and place a mark at its center as well.

Place a line of test tiles along the base of the wall, using the center mark you made in Step 5 to align the middle tile. Extend the tile line outwards, leaving a gap between the tiles by using tile spacers. Check the sizes of the tiles on the ends of the line. If the edges contain partial tiles wider than half of a single tile, then leave the row as is. If one of the end tiles would be shorter than half a tile width, then shift the row over in that direction until you have a full tile on one edge and a partial on the other edge.

Spread a layer of tile adhesive onto the wall along the base at the guideline, using a notched trowel. Tilt the trowel and run the notches along the trowel's edge over the adhesive to raise ridges across the adhesive surface. The ridges will help the adhesive to spread evenly across the rear of the tiles when you press them into place. Press the first row of tiles onto the adhesive. Use the guideline to position the bottoms of the tiles, and place tile spacers between the tiles to create joints. Begin in the center and tile outwards until you reach the edge. Cut the partial tiles for the edges with a tile saw, then place them onto the plastic shower wall as well.

Spread adhesive for the next row, then continue placing the tiles, positioning a spacer between rows as well, to create uniform joints. Continue tiling upwards until you clear the level of the showerhead, to prevent splashing water from running beneath the tiles. Cut tiles as needed with the tile saw for placement around the fixture holes. For round fixture holes, use a hole saw of the same diameter to drill through the tiles where necessary.

Level the tiles by placing the carpenter’s level across adjacent tile surfaces and then pressing higher tiles deeper into the adhesive, or adding more adhesive under lower tiles. Allow the tile adhesive to cure overnight.

Remove the tile spacers, then grout the tile using a grout float to push the grout into the joints. Wipe off any excess once you’ve filled the joints with grout, using a damp sponge. Fill all joints, except for the ones running along the base and on top of the tiles, with grout. For the base, use a bead of silicone caulking between the tiles and the shower base. For the top of the tiles, place a second line of caulk along the tiles to prevent moisture from flowing underneath.

Allow the grout seven days drying time, then remove the masking tape. Restore the fixtures, and place a bead of caulk around the fixture bases where they meet the tiles to waterproof the joints. Restore the water source.

Spray the tiles and grout with a tile and grout sealant to add additional waterproofing. Allow the sealant and new caulk 48 hours drying time before using the shower.