Whether you are retiling a shower or tiling an existing shower for the first time, you will need to gut the shower stall down to the studs. You may need to remove the shower pan and ceiling as well. Make sure the surface onto which you plan to affix the tiles is strong because tile is heavy. Our shower has a cement backer onto which we'll be laying the tiles.
Measure all surfaces of the shower that will be tiled for length and width (Images 1 and 2). You'll need these measurements to determine how much tile, cement and grout you'll need. A paper drawing of the area to be tiled will help to determine the proper number of tiles and other materials needed. You will need graph paper and a pencil for that. If you're tiling on existing construction, you'd need to put up a sturdy cement board backer over the studs.
Tiles come in a wide variety of materials so decide which material will work best for your space, especially in terms of design and maintenance. Make sure you use tiles made for walls. Decide on design and layout, and choose a starting point. Measure up from the bottom of the backer board the height of a tile minus 1/2". This will give you a 1/2" overlap over the tile lip on your shower pan. Mark this with a sharpie and using a level, transfer the mark across the shower stall. This will be a guide for the top of the first row so that all tiles will be level.
Choose your setting material and prepare it. Mix enough thinset for the bottom row. Follow the directions on the bag of thinset as to what type of trowel you will need. At your designated starting point, trowel on some thinset and spread it with a notched trowel (Image 1). With the notched edge of the trowel, comb the material into ridges. Then set the tile into it by twisting slightly while pushing into the thinset. Remove the tile to make sure you have good coverage on the back. Reinstall and keep setting the tiles (Image 2) using spacers in between. Let the bottom row set for up to 24 hours. Pick out the right trowel for your thinset and tile size, also pay attention to spacing recommendations and use the right spacers. To achieve an even tiling job, use consistent measurements for the space between your tiles where the grout will go. This measurement may vary depending on what you prefer, but 1/8" is a good standard. Shim in some spacers between your tile rows (Image 3). How many and where will vary depending on what kind of tile you're using, so find out what your tile manufacturer suggests. Since most adhesives set in 20 to 30 minutes, quickly wipe away any excess. With thinset mortar, use a sponge and water. Repeat the procedure, setting each row of tile on top of the last row of tile. Continue until you reach the top of the shower stall.
Measure up from the top of the last row. Mark a line with a level as a guide for the next row. As you reach the corners of your shower, you'll need to measure and plan to custom cut the tiles to be put in the spaces that do not accommodate a full tile. Cut the tiles using tile nippers or a tile saw. Our job requires we tile vertically around the tub surround, so it is important to see exactly what areas will be covered with the tub and which areas will be open for us to tile upon after we apply a backer board. Always wear protective eyewear when cutting tile. Before cutting tile, all cut lines should be marked with a pencil. Use a tile cutter for all straight cuts. It scores the tile and then snaps it along that score. To cut away small sections of tile, use tile nippers, which take small "bites" out of tile. For more complex curves or edges, use a rod saw, which can make more accurate and smooth cuts. After making any tile cut, smooth the edges with sandpaper or a tile sander.
Let the tile set for 48 hours. If you'll be installing any new appliances into/onto the areas around which you are tiling, now would be a good time to dry fit the appliances into their designated areas to make sure no changes will need to be made prior to finishing your tile job.
After placing all of your tiles, mix your grout to a thick paste and apply, pressing it between tiles using a grout float. Spread grout paste with a firm, sharp rubber float. Work the grout paste into the joints until completely filled, making certain the paste is not just sitting on top or "bridging the joint." Be sure to pack all joints firmly. Don't grout the whole shower at once. You will want to be able to wipe the grout after it sets, but before it is too hard to remove from the tile. Remember you are not going to grout at the corners, you are going to caulk, so try to maintain an even spacing.
Remove all excess grout from the face of the tiles with the edge of the grout float. Work the float at a 45-degree angle, diagonally to the grout joints, to avoid pulling out the paste. Remove any remaining grout with a damp (not wet) sponge or towel. Work the strokes diagonally to the tile joints and allow floor to dry. Wait about 20 minutes for grout to set and repeat the rinsing of the tiles. Then let the grout set for at least 24 hours. Wet down the grout joints with clean cold water during this period. If a haze appears on the surface of the tiles after grout is dry, buff off with clean dry cloth.