Grouting tile, and then sealing the grout, are the final, crucial steps in any bathroom tiling job. The grouting process is simple and straightforward and will not take much time to complete. Doing a good job is important, however, because you will have to live with the results for a while, and the grout will have to stand up to the bathroom's damp, high-traffic environment. So plan ahead and complete your due diligence before adding water to your grout and mixing.
Use a drill and mixer to mix grout with water according to directions on the package to a peanut-butter-like consistency.
Use a margin trowel to load a grout float with grout, and spread the grout over the wall tile using upstrokes. Focus on forcing grout into the grout lines.
Allow the grout to set up for 15 to 20 minutes. Then, with a bucket of warm water and a grout sponge, begin removing the residual grout and grout haze from the faces of the tile. Form the grout lines to their finished quality as you go.
Allow the grout to cure for 72 hours. Then apply two to three coats of a high-quality penetrating grout and tile sealer to the grout lines with a brush bottle. This will prevent mould and mildew growth in showers and around floor tiles, prevent water from getting under the tiles and loosening them, and help the grout keep its beauty over time.
Allow the sealer to dry completely between coats. When the last coat of sealer is dry, the shower is OK to use. If grouting around floor tile, follow the same steps as above. Use the same colour of grout and the same tile spacer size for the floor and the wall. After the grout has cured for 24 hours after installation, your tiled bathroom floor, wall or countertop is ready for use.