Actually putting the tile on the wall or floor of your shower stall is only part of the overall installation. When it comes to finishing a shower stall, there is another important aspect: grouting. Grout is a cement-based mixture that fills the gaps between tiles and helps to lock the pieces in place as well as provide color accents or blending, based on the color you choose. The basic principle of grouting is “make a mess and clean it up,” although there are a few things to keep in mind so you have a professional finish upon completion.
Mix the grout in a bucket, using the margin trowel. Follow the directions on the bag of grout for the amount of water needed. Aim for a thick, creamy, peanut-butter consistency.
Let the grout sit for 15 to 20 minutes. This is known as slaking and lets the pigments and other elements in the grout completely absorb the water. While you are waiting, mask off any edges around the tile stall -- such as against the wall -- so you don’t get grout on the other surfaces.
Remix the grout until it is creamy and smooth.
Scoop some grout out of the bucket and smear it onto the bottom of the wall. Hold the float at a 45-degree angle. Apply pressure as you move the grout around, forcing it into the joints. For best results, pull the grout up the wall, using different angles and covering joints from more than one angle to ensure they are filled. Hold the grout float at a 90-degree angle and pull it diagonally across joints to remove excess from the tile face.
Work your way up the wall for at least 30 minutes. Check the grout joints where you started. If they are hardening to the point where no grout sticks to your finger when you lightly touch the joints, they are ready for washing. Otherwise, continue until you finish smearing and filling the joints.
Fill a bucket with water. Dampen a sponge. Start at the bottom of the wall. Apply light pressure and use circular motions to smooth the joints and remove excess grout from the wall. Wring the sponge out frequently. Work your way up the shower stall. Cut grout out of the corner joints and from around fixtures such as soap dishes, using the tip of the margin trowel.
Change the water in your bucket. Wait 30 minutes until the remaining grout haze forms a film over the face of the tile. Dampen the sponge. Apply gentle pressure and wipe diagonally across the joints to remove the final grout haze. Remove the masking tape.
Wait 24 hours. Fill a bucket with water. Cut the tip off a caulking tube, using the utility knife. Apply masking tape to either side of the corner joints that need to be filled with caulking.
Press the tip into the joints of the corners and around soap dishes and other fixtures. Fill the joints with caulking until they are flush.
Smooth the caulking with your finger and remove excess, using a damp sponge. Remove the masking tape. Smooth the remaining rough edges with the damp sponge. Allow 48 to 72 hours before using the shower.