If you discover water damage—punky, soft mortar—chip out the bad stuff behind adjacent tile and keep removing mortar until you reach solid ground. If the repair spans two studs, I find Dens-Shield tile backer easier to work with and more moisture-resistant than either green drywall or concrete backerboard. For smaller repairs, use a method similar to that used for patching plaster walls.
Repair damaged backing.
Step 3: For one tile, mix 2 cups of Durabond 20 adhesive with water. With a 1″ plastic putty knife, push the Durabond through the lath. Form a key behind the original mortar. Get as much around the edge as possible. (If you’re repairing the damaged subsurface of a floor, use a cementitious filler/leveler.)
Step 4: Remove the tie wire. Fill the middle, leveling the surface even with the original mortar. Crosshatch the Durabond to provide “tooth” for the tile adhesive. Replace
Now that you’re ready to set tile, you’ll find professional tilesetter’s tools reduce breakage:
5⁄8″ carbide-tipped, tile nipper for making round cut-outs around pipes
tile cutter (a rental tool) or an electric tile saw (also a rental tool)
60-grit rubbing brick to smooth rough edges
tile spacers to maintain uniform grout lines
12″ carbide hacksaw blade for square cut-outs
You’ll also need a notched spreader to apply adhesive, a rubber tile float or squeegee, a sponge, and a toothbrush to finish the grout joints.
Step 1: Mark tile for cutting with a strip of masking tape. For cutting with an electric tile saw, transfer the cut line to the back, using a wax crayon to prevent the line from washing off. Shave rough edges or plane them with a 60-grit rubbing brick. Step 2: To make square notches, clamp tile on a rubber pad and use a 12″ diamond, hacksaw blade or rod saw.
Step 3: For round holes, place tile on a rubber pad (such as a mouse pad), and outline a circle with holes drilled with a masonry or ceramic-tile drill bit. For rare tile, consider using a “hole breaker tile vise.” This tool reduces breakage. Then cover holes for pipes with escutcheons. Reattach
While there are several types of adhesive, from solvent-based to epoxy, the one I prefer for wall tile is a Type I acrylic. (Type I means the adhesive is water-resistant.) Super-Tek Dual Purpose Adhesive can be used on almost any subsurface, and a tile pressed in place, top or bottom first, won’t slide down. It also has a long “open time,” which allows you time to place additional tile, clean tools, and remove the excess that squeezes up through the grout joints.
On floors, use a cementitious, thin-set adhesive (with an acrylic or latex additive, depending on the product). Thin-sets support more weight, so they’re needed for floors. To set fixtures, such as soap dishes, use a fast-setting adhesive, such as Super-Fixset, which hardens in 10 minutes. Hold the fixture in place meanwhile with duct tape.
Step 1: With a notched plastic spreader, apply Type I ceramic tile adhesive from edge to edge over the patched subsurface. Step 2: Position tile, using plastic spacers to maintain joint width. Tap lightly on a padded 2×4 to flatten high spots.
Grout your tiles 24 hours after they have been set. Use the waiting period to make up trial batches, working with powdered colorant and sand until the dry sample matches the original. Use teaspoons and measuring cups to keep color uniform. Scale up, if you’re regrouting a large area.
Step 1: Working diagonally, push grout between the tile with a rubber tile float. Wipe off excess with squeegee or float.
Step 2: Sponge tile, rinsing frequently. Run a toothbrush handle down the grout joints to compact them. When a powdery film forms on the tile, polish the haze off with a soft cloth.