Note that the adhesive must be completely dry before moving on to this step.
10.1. Begin with the wall surfaces. Dampen the tiles with clean water before starting to apply the grout. That way, the mixture will be easier to apply and will have less tendency to stick to the surface of the tiles, which makes them easier to wipe clean afterwards.
10.2. Mix the grout according to the manufacturer’s instructions. The grout should be a uniform colour and the consistency of toothpaste.
10.3. Pour some of the grout directly onto the tiles and work it into the joints using a rubber float.
10.4. Apply the grout section by section, covering an area no bigger than 10 sq. ft. at a time. Hold the float at a 45° angle.
10.5. Do not grout gaps separating the tiles from other types of material, the shower curb, or faucets. These gaps must act as expansion joints and will be sealed later.
10.6. Since grout dries fairly quickly, it is a good idea to have someone help you at this stage; one person trowels in the grout while the other wipes off the excess a few minutes later, both working in the same direction.
10.7. Grout the floor tiles and the curb.
10.8. Use the float to remove the excess grout from the entire tiled surface.
10.9. Clean the surface with a damp sponge, working diagonally over the tiles. Rinse the sponge often, using as little water as possible so as not to dilute the grout. Remove as much milky residue as you can.
10.10. After 24 hours, when the grout is completely dry, apply grout sealer to the joints. Avoid spreading the sealer onto the tiles. Apply another layer thirty minutes later.
10.11. As an alternative you can use epoxy grout, which is both stain and mildew resistant and easy to clean. This type of grout is more difficult to apply, however, because it sets very quickly.