Lay out the backsplash, wall tiles are typically thinner and lighter in weight than floor tiles. Many are made with built-in spacer on their edges, also known as lugs. If your tiles don’t have lugs, ask your tile dealer for the proper size plastic spacers. Using spacers between the tiles will help maintain the proper gap and prevent the tiles from slipping downward before the adhesive sets up. The mortar will not adhere to the spacers; they can easily be removed and discarded before the joints are filled or grouted.
The backsplash space between a tub and wall shower fixtures usually can be filled with two or three horizontal tile rows, depending on the size of your tiles. Because tiles create a grid-like pattern, try to choose tiles that fit this space — wall installations look better when they are vertically even and symmetrical from end to end. Bull-nose or edge tiles of various sizes are also available to finish edges, fill gaps or to avoid having to cut tiles to fit.
Check that the shower tub is level. If it is not, stand a tile at the lowest spot and mark a level line on the wall at the tile’s top — this will be your starting point. Use a standard level to extend this reference line across the wall and around the entire area that is being tiled.
The tops of all tiles in the bottom row must meet this line or be cut (from the bottom) to line up with the mark. Tiles installed above this line will not require cutting.
To ensure a symmetrical layout from end-to-end, measure and mark the center point of each area being tiled. Before you apply mortar and begin to tile, do a dry run by lining up the edge of one tile with the center mark, then place tiles side by side to determine how many tiles will be needed and the width of the end pieces. Don’t forget to include spacers between each tile.
If the end pieces will be very small or odd-sized, you may be able to adjust the spacing slightly to avoid having to cut the ends. If this does not work, repeat the dry run but place the first tile directly over the center mark, which may enable you to cut equal-size end pieces, often from a single tile. If one side of your tile work will have exposed edges, use whole tiles near this edge and cut only the tiles that end at the wall.
Wall tile adhesive comes pre-mixed or in powder form. If you are using the powder mix it with water until it is the consistency of peanut butter. Apply it with a notched trowel sized to your tile. Use the flat side of the trowel to spread the mortar onto the wall, starting at the center mark and working up to the horizontal reference line. Tile adhesive dries rather quickly, so spread only as much adhesive as you can tile in about 15 minutes.
If you have a vertical border row, start there and remember to put a spacer at the bottom to allow room for caulking between tub and tiles.
If you are installing sheets of smaller tile with mesh backing like we are, use a utility knife to cut the sheet to size. Press it firmly with your hands then use a clean grout float to tamp it onto the adhesive.
After you have completed two or three rows, measure and cut corner tiles to size and set them in place with the cut edges facing into the corners. For smaller cuts on ceramic, porcelain or stone tile, you can use a tile nipper to round corners or make small cuts.
Before applying grout, allow the tile adhesive to set for 24 hours or as the manufacturer recommends. Un-sanded grout is usually specified for wall installations, glazed tiles, and tile with narrow grout lines. Pre-mixed grout is available in a wide variety of colors to match or contrast with your tiles. Grout can dry out, so mix only what you will be using in the next 20 to 25 minutes.
Wipe down the tile with a barely wet sponge to make sure there is no dust on them before you grout. Remove the plastic spacers. Apply grout with a rubber float working diagonally across the tile. Do not grout the bottom seam where the tile meets the tub, you’ll want to use caulk in that seam. Use the float to take off any excess grout then allow the grout to set for 10 minutes.
Use a damp sponge to wipe off the excess. Rinse and wring out the sponge frequently. Do not wet the grout, it will weaken the bond. After the grout has dried completely, clean any grout haze off the face of the tiles with a commercial release agent. Wait a couple days then apply a grout sealant.