Repairs to bathroom shower walls can be challenging since the job requires several skills that must be performed in a tight location. Since shower walls are often tiled, repairing a hole may require replacing both the tile and the cement board underneath. This task could be complicated by pipes and wires running behind the damaged area. However, if done well, the repaired area should be indistinguishable from the rest of the shower wall.
Demolition and Patching
Remove any remaining pieces of broken tile surrounding the hole, using a small pry bar or chisel.
Fill a small hole -- less than a few inches in diameter -- with filler compound approved for high-moisture areas, using the small putty knife. Let the patch dry and cure according to the package instructions.
Prepare holes that are too large to fill by removing tile and cement board. Cut the tile and cement board with a keyhole saw, removing enough material to expose the nearest wall stud.
Cut a new piece of cement board large enough to cover the exposed area. Secure it to the stud using screws and a drill.
Fill gaps between the cement board with joint filler, using a putty knife. Let it dry according to the manufacturer's instructions.
Smooth the patched cement board with sandpaper. Wipe away the sanding dust.
Lay out your replacement tiles to ensure they fit properly. Cut any tiles that are too large using the tile saw.
Apply a coating of thin-set mortar to the repair area, using the flat side of the notched trowel. Scrape grooves into the thin-set mortar, using the square-notched side of the trowel.
Lay your tiles into the mortar. Press them gently into place.
Apply a strip of painter's tape across the tiles after they are all in place to ensure they do not fall off while the mortar is drying. Allow the tile to dry for at least 24 hours.
Remove the painter's tape. Check for any loose tiles.
Select a tile grout that matches the color of the shower's existing grout.
Mix the grout according to the package instructions. Apply and press the grout between the tiles, using the rubber float.
Remove any excess grout by lightly wiping the surface with the sponge and warm water. Wipe across the gaps, not with them, so you don't pull out the grout.
Allow the grout to dry according to the manufacturer's instructions.
Clean the newly tiled area with warm water.