- 1). Remove damaged tiles by prying them loose with a flat chisel.
- 2). Cut the broken edges of the old drywall with a drywall saw to create neat and straight seams.
- 3). Scrape off any residual caulking from the shower base or bathtub base with a sharp razor knife.
- 4). Scrape off old grout with a grout saw from surrounding tiles around the immediate damaged tiles. Remove a thin layer of grout.
- 5). Soak the old tiles in boiling water and scrape off old mastic with a wide putty knife from the back of the tiles. Do this only if the tiles are salvageable. If the tiles are broken, replace them entirely.
- 6). Measure the section needed for the new baseboard and mark it on a new piece of cement backer board. Slice through the fiberglass mesh and score the marked line with a utility knife. Score the baseboard until it can be snapped off. Fit the backer board into the wall to make sure that it fits, with the smooth side facing outward.
- 7). Attach the new backer board by hammering roofing nails into the wall studs. Keep the backer board a little above the shower or bathtub's base, leaving about 1/8-inch space between the base and the bottom of the backer board.
- 8). Apply latex mastic on the backer board with a 1/8-inch notched trowel. Spread evenly on the surface.
- 9). Press the new or salvaged tiles on the backer board, aligning joint lines to maintain uniform joints. Let the mastic dry for three days.
- 10
Mix powdered grout with a latex additive following the manufacturer's directions. Apply the grout mixture into the joint lines with a rubber trowel. Wipe off excess grout with a damp sponge and let the grout dry for two to three hours. Then buff the tiles with a soft cloth. - 11
Fill in the gap in between the shower base and wall with silicone caulk. Fit the caulking tube in a caulking gun and squeeze a small amount into the gap. Smooth out excess with a gloved finger. - 12
Finish by sealing the grout joints with liquid silicone sealer.
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