How To Install Bathtub Insert Walls with Tile

Measure the bathtub walls over which you want to install tile and bathtub insert walls. Cut cement backer board or green board down to these sizes if the walls have exposed studs.

Hold the backer board or green board piece up to the wall where you want to install the bathtub insert walls. Pull the board away from the wall at the top and make a mark on the front side of the board in each location where the board hits a wall stud. Then move to the bottom of the board and mark the studs again. Drive 1 1/4- to 1 1/2-inch screws into the backer board every 6 inches along each stud to secure the backer board in place.

Measure the backer board walls. Cut the bathtub insert walls down to size if necessary with a carbide blade saw. Clean the back of each panel with alcohol and allow the surface to fully dry.

Place 1-inch dots of silicone caulk on the wall surface. Space the dots every 6 inches and press the insert walls into place on the backer board, pressing each section of the insert hard against the wall. Let the insert panels dry for 24 hours before installing surrounding tile.

Wipe the areas of the walls where you want to install tiles with a tack cloth. Apply a layer of thin-set mortar to the wall space and apply the tiles to the wall, with tile spacers between all of the corners to maintain the correct spacing. If tiles need to be cut to fit the space, use a tile saw.

Give the tiles 24 hours to dry, pull out the tile spacers and spread grout over the tiles with a float to fill the spaces. Squeeze a line of silicone caulk around the edges of the tile, at the seams where the tiles meet the bathtub insert walls and around fixtures. Allow the grout and caulk to dry for 48 hours before allowing the shower to get wet.