Renovating a tiled bathroom shower is a challenging task, but the do-it-yourselfer with the right equipment, patience and time can renovate a tiled shower that will add value and beauty and functionality to the home for years or even decades to come.
Ripping out the old
Turn off the water supply to the shower. In some cases, this may mean shutting off the water supply to the entire home. Make sure that if you accidentally break a pipe you don't also destroy your home with a flood. There's no such thing as a tiny flood if you burst a main pipe.
Using a hammer and/or pry bar, break the existing tile and backboard, and remove them. When you are finished, you should be down to bare studs.
Remove any screws, or other protrusions that will prevent a tight and even fit when adding new wallboard.
Add Fresh Wallboard
Staple plastic sheeting to the studs to create a moisture barrier. Using your hammer batten down any staples that don't sink in all the way.
Measure and cut your cement board to size. Cement board can be found any nearly any home building supply store. A circular saw with a diamond blade is the best tool for this task. Be sure to measure for a tight fit. Cement board is less forgiving in terms of gaps, especially when working with showers.
Using ceramic screws, to prevent rust or discoloration, fasten the cement board to the studs.
Tile the Shower Stall
Find the true center of the surface of one of your three shower walls. You will be laying your tile from the center out. Chalk lines should serve to mark your angles. Be sure to use both a horizontal and vertical level to determine that your lines are straight.
Mix enough mortar to use in about an hour of setting tiles. Using your trowel, trowel the mortar onto the wall. Then set your first tile.
Use spacers in between your tiles to create even spacing and to keep the tile lines straight as you go along. The whole span to be tiled. Do the same for your additional wall spans.
Mix enough grout to fill the gaps in between the tiles.
Using your grout float, push grout into the gaps between the tiles to fill the gaps evenly.