Tips for repairing bathtub tile include replacing the supporting wall and preventing further damage by replacing grout. If the tiles are still serviceable but the drywall supporting them becomes wet, it requires replacement. Most of the time owners can save the tile, which is a good idea, as finding exact replacements is often very difficult. After removing the tile, cut away the damaged drywall and replace it with concrete backerboard before reinstalling the tiles.
Removing tiles from saturated drywall is usually easy; however, as the removal moves away from the water-soaked area, tiles become more difficult to remove. Sliding a wide putty knife behind the tiles is sometimes helpful. To remove firmly attached tiles, it may be necessary to cut the drywall from behind and soak the pieces in boiling water to loosen the glue.
Concrete backerboard is a superior option for installing tile in areas exposed to water. The concrete does not suffer water damage like wallboard and protects the studs in the wall from water damage. The manufacturer covers the backerboard with fiberglass fibers so tile adheres well to it.
If the wall behind the tile is still in good shape, but there is some damage to the grout, early intervention prevents having to remove and replace tiles. A power grinder makes removing the damaged grout easier. After removing the dust, apply new grout using the manufacturer's directions.