A backsplash is the protective wall covering behind a sink, which prevents moisture from damaging the wall. It can be made of any waterproof material, but tile provides the widest range of colors and styles. If you have an old tile backsplash, you must remove it before you can install a new one. The good news is that you know the wall behind the backsplash is already suitable for tile. Make sure your new backsplash is at least as large as the old one, so you don't have to touch up the paint around the edges.
Things You'll Need
Thinset tile mortar
Notched tiling trowel
Standard wall tiles
Bullnose wall tiles
Remove the existing tiles of the backsplash with your hammer and chisel, tapping at the sides of the tiles where they meet the wall. Scrape the wall with a razor scraper once the tiles are off to remove any residual mortar or glue.
Use a pencil, level and tape measure to mark the dimensions you want for the new backsplash. Line up the bubbles on the level in the lines indicating level and plumb before you mark the wall. Size the perimeter so it will hold all full tiles with no cuts, leaving room for a border of bullnose tiles. Bullnose tile are those that are finished on one edge.
Spread thinset mortar over the whole marked area with your notched trowel.
Set the bottom row of tiles in place in the mastic, along the surface of the countertop. Set spacers between and below the tiles separating them from the countertop.
Install the second row of tiles above the first, again putting spacers around each of them as you press them into the mortar. Repeat and continue, building your way up the wall row by row, covering the whole marked area.
Use your trowel to spread mortar on the back of a bullnose tile. Press it onto the wall at one edge of the tiled area, so the unfinished edge of the tile is facing the backsplash and the finished side is facing out toward the open wall. Repeat the process to hang the rest of the bullnose tiles in a perimeter around the backsplash.
Let the tiles set for 12 hours. Remove the spacers.
Grout the tiles with a grout float, spreading the grout over the surface and forcing it down into the spaces between the tiles. Use a damp sponge to wipe off the excess grout.
Let the grout set for 48 hours. Run a bead of caulk along the bottom of the backsplash where it meets the countertop.