Applying waterproofing silicone to tile joints can help prevent water damage and mold growth.

Applying waterproofing silicone to tile joints can help prevent water damage and mold growth. Clean the tile joints thoroughly. Remove any old grout, dirt, or residue.
Make sure the area is dry before applying the silicone. Apply painter's tape to the edges of the tile joints to create clean lines and prevent the silicone from spreading onto the tiles. Cut the tip of the silicone tube at a 45-degree angle to the desired bead size. Puncture the inner seal if necessary. Load the tube into the caulking gun and apply the silicone evenly along the joint. Keep a steady hand and try to maintain a steady bead. Use a caulking tool or your finger, dipped in water or a mild soap solution, to smooth the silicone and press it into the joint. It helps to create neatness and ensures good adhesion.
Carefully remove the painter's tape while the silicone is still wet to avoid stretching any of the silicone. Allow the silicone to cure according to the manufacturer's instructions, usually 24 hours, before water or heavy use. This process helps ensure a watertight seal and professional finish for your tile joints