How to Make Mosaic Countertops

Sand the counter surface with a belt sander to remove all shine. Wipe up the dust.

Measure across the countertop and mark the center. Mark a line front to back at the center, using your pencil and square.

Spread tile mastic over the counter with a notched trowel. The middle line should still be visible through the combed pattern of the mastic.

Press trim tiles along the front edge of the counter, starting at the center and working to the sides. Cut the two trim tiles at the ends on your tile cutter, as needed, to fit.

Press the first sheet of mosaic tiles into the mastic behind the front line of trim tiles, on one side of the center line. Put spacers between the tile sheet and the front row of trim tiles. Press down on the individual mosaic tiles one by one to make sure they’re all set.

Set the next sheet alongside the first one, with spacers between them. Repeat, covering the whole counter in the sheets of tiles.

Use your razor knife to cut through the mesh of the tile sheets at the ends, so they will fit. If necessary, cut the individual tiles at the ends with your tile cutter.

Let the mastic dry for 12 hours. Remove the spacers.

Spread grout over mosaic tiles with a grout float, forcing the grout into the spaces between the tiles. Use a damp sponge to wipe off the residual grout.