Turn off the power to the outlets on the side of the room you are working on. Unscrew and remove the outlet covers to any outlets in your work area.
Wipe down the drywall with a dust cloth. Grout adheres best to clean surfaces.
Cover your countertops with newspaper. Tape the newspaper in place with painter's tape. This keeps your newspaper from moving around while you work.
Install 1/8-inch spacers around the tops of your counters.
Measure the length and height of the space you plan to tile. Multiply the backsplash's length by its height to determine how many tile sheets you need. Glass tiles typically come in 12-by-12 sheets. Thus, if your counter is 10 feet long and 3 feet high, you will need 30 glass tile sheets to complete the project.
Mark a focal point for the installation by placing a piece of painter's tape against the counter in the designated spot. The focal point determines where your line of tile begins.
Place each tile sheet against the wall. Mark where each tile sheet ends and a new sheet begins with a pencil. Cut your tile sheets with scissors to fit properly around cabinets and electrical outlets during the installation.
Mix the thinset mortar in a plastic bucket following the manufacturer's instructions. If your mortar mix did not come with instructions, add water and mix until the mortar is the consistency of peanut butter.
Apply a 1/4-inch deep layer of thinset mortar to the wall with the notched trowel. Smooth out the ridges in the grout with the trowel edge.
Press each sheet of glass mosaic tile into the mortar starting at the focal point line and working upward and outward. Lay a flat board over each tile sheet. Tap the board gently with a hammer to set each tile sheet in place. Let the tile dry for approximately 30 minutes.
Wipe down the surface of the tile with a damp sponge. Peel away the surface paper from the tile.
Mix the grout in a plastic bucket. Wipe the tile with the damp sponge. The moisture helps the grout move smoothly across the tile and into the gaps. Scoop up a generous amount of grout with the trowel. Move the trowel across the tile, working the grout into the empty spaces.
Move the trowel edge back across the freshly grouted surface, smoothing the grout and removing excess grout from the tile surface. Wipe down the backsplash with a clean, damp sponge. Let the tile cure for 24 hours.
Buff the backsplash with a dry, lint-free cloth. This removes the grout haze – leaving you with a shiny backsplash.
Remove the 1/8-inch spacers, tape and newspaper.Apply a thin bead of silicone caulk in the empty space between your glass tile sheets and the countertop.
Replace the electrical outlet covers. Turn the power back on.