How to Build Up Back Splash Walls

Measure and mark the dimensions you want for the backsplash on the wall, using a square and a pencil. Make it a size that will encompass all full tiles, without cuts, leaving enough space around the edges for trim tiles.

Run a vibrating sander over the wall within the marked area to get it dull, smooth and flat.

Spread thinset mortar over the wall within the marked area, using a notched trowel.

Set the lowest row of standard tiles into the mortar, along the countertop. Set spacers between the tiles and the countertop and between the tiles themselves, so each tile is spaced all around. Leave enough room at either end of the trim tiles. Repeat, working your way up the wall course by course.

Spread mortar on the back of a trim tile with a notched trowel. Press the tile to the wall, on the perimeter of the tiled area, with the finished edge facing out. Put spacers between the trim tile and the standard tiles.

Repeat, hanging trim tiles all around the perimeter of the backsplash. Let the mortar set for 24 hours. Pull out the spacers.

Spread grout over the backsplash with a grout float, pressing it into the spaces between the tiles. Fill all the lines except the one between the bottom row of tiles and the countertop. Wipe up the residual grout with a damp sponge.

Let the grout set 24 to 48 hours. Caulk the space between the bottom row of tiles and the countertop.