Check that the countertop 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 or laser level to extend this reference line across the wall and around the entire area that is being tiled
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 (image 2). 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 mastic 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 countertop and wall cabinets 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 countertop 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 or laser level to extend this reference line across the wall and around the entire area that is being tiled (image 3). 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. If you are tiling all the way up to the cabinets, place the cut tiles or uneven gap just below the cabinets where it won't be as noticeable.
To ensure a symmetrical layout from end-to-end, measure and mark the center point of each area being tiled. Before you apply mastic and begin tiling, 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 (image 4). Don’t forget to include spacers between each tile, if required.
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.
If you are tiling over painted drywall, use course-grit sanding sponge to rough up the surface. This will help the mastic adhere better to the wall. Wipe off the dust and debris with a damp rag.
While you are dry-fitting the tiles and before you apply the mastic, make your bottom row and end cuts. Top-row tiles, sized to fit under cabinets, and special cuts are better made just as you are about to install them.
You can use a manual snap cutter (image 1) for most ceramic or porcelain tile. The cut edges will likely be rough, use a sanding stone to smooth them over (image 2). For glass or larger size tile, using a water-cooled, power wet saw will produce smoother, more precise cuts (image 3). Cut tiles as needed for electrical outlets, pipes or other obstacles. You can also use a power drill with a tile-hole saw, an angle grinder with a diamond-grit blade, or a hacksaw or file with a carborundum blade.
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. For most wall tiles, the trowel will have 1/4- or 3/8-inch notches. Use the flat side of the trowel to spread the mastic onto the wall, starting at the center mark and working up to the horizontal reference line. Then, turn the trowel around and hold it at a 45-degree angle to rake the mastic with the notched side, creating ridges of the proper depth. 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 (image 1). If you do not have a border, being with the bottom row at the center mark, press the tiles firmly into place, placing spacers between each tile if required. Avoid squeezing the mastic into the joints. If corner pieces must be cut to fit, do not set them in place just yet.
When the first row of tiles is complete, begin the second. Work upward one complete row at a time. Spacers are especially important between horizontal rows to maintain an even grout space between the tiles. Periodically check your work to ensure that the tiles are securely bonded to the wall, and use a straightedge to make sure the rows are level.
If you are installing sheets of smaller tile with mesh backing like we are (image 2), 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 (image 3).
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. When you reach the top row, cut the tiles as necessary to fit around the cabinets. For smaller cuts on ceramic, porcelain or stone tile, you can use a tile nipper to round corners or make small cuts.
If you are tiling a small area where you can't fit the trowel into, apply the adhesive directly to the back of the tile — known as "back buttering".
Before applying grout, allow the tile adhesive to set for 24 hours or as the manufacturer recommends. Unsanded 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. To prevent grout from staining or sticking to porous natural tiles like stone and terra cotta, check with your tile distributor to see if they require a commercial sealer before you apply grout.
Use a mixing attachment on a variable-speed drill set at low speed to mix the grout to the consistency of peanut butter. 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. Hold the float at a 45-degree angle as you work the grout into the seams. Do not grout the bottom seam where the tile meets the countertop, 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. Wipe at a 45-degree angle across the grout lines to avoid raking the grout out of the joints. 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.
Complete the installation by replacing the wall receptacles. You'll probably need longer attachment screws to compensate for the thickness of the tiles.