When installing a shower, one of your most important tasks is to seal the shower properly. A shower without the proper sealing will leak. This can cause water damage to the subfloor underneath the shower. If the shower is on the second floor it may cause ceiling leaks and water damage to the lower floor. Proper sealing requires that you apply silicon around the shower lip and grout the tiles along the shower walls.
Mix your grout according to the instructions on the package.
Place a small amount of grout on the joint of the tile.
Push the grout diagonally along the tile using a padded grout float. Hold the float at a sharp angle and run it along the tile face to remove any excess grout.
Clean the face of the tile with a wet sponge to remove any of the excess grout from the tile face.
Run the padded float parallel to the joint to shape the grout line. Wash the tile face again with a wet sponge. Let the tile harden a few days before the next step.
Apply caulk to the area of the wall where the tiles and the bathtub portion of the shower meet. Also apply caulk along the floor tile. Insert a silicone caulk into a caulking gun and cut off the tip of the caulk tube using a pair of scissors. Press the trigger for the caulk gun to get a small flow going then wipe the tip. Apply the tip in a smooth line along the caulking joint.
Apply a silicone grout sealer to the joints between tiles using a small sponge with a handle. Apply according to the instructions on the label.
Allow the shower to dry for a 48-hour period before sealing with grout.