How to Lay a Stone Tile Floor

The next day, wash away thinset residue with muriatic acid, and, to protect the stone from grout stains, apply a sealer. When that's dry, mix up a sanded grout and push it diagonally into the joints with a grout float. Wait 10 minutes, then wipe off grout residue from the stone with a damp sponge, rinsing it often. Don't disturb the joints. The next day, rub off any haze with cheesecloth and wipe on a final sealer coat.