Silicone caulk in a bathroom provides a much-needed barrier of protection between your fixtures and walls and the moisture inherent in a bathroom. Caulk prevents water from penetrating wall surfaces, holding off mould and mildew that can easily grow in a bathroom. Over time the silicone will start to erode around all fixtures, including your shower faucets. Removing the old caulk and reapplying new silicone is the only way to ensure that your faucets stay sealed against leaks and mould growth.
Dry the area around the shower faucet with a towel. Peel off any old caulk that is sticking out or hanging down. Dispose of old caulk safely in a dustbin.
Rub caulk remover onto the caulk around the faucet. This material will soften the caulk, making it easier for you to remove it and make room for the new silicone.
Cut into the old caulk with a sharp utility knife. A lot of the caulk will probably just fall out. Once you have softened and loosened the caulk, pull any remaining old caulk out of the area around the faucet with needle-nosed pliers.
Run the hook of a five-in-one painting tool into the gap left over by the caulk to remove any remaining small pieces of old silicone. Use a flashlight if necessary to see into the gap, making sure you've removed all old silicone.
Clean the joint with a bathroom cleaner that does not contain ammonia. Rinse the area thoroughly when you have removed surface dirt, dust and soap scum.
Mix 1/3 cup of household bleach into one gallon of water. Dampen a rag in the mixture and rub it into the joint to kill mould or mildew. Scrub with a scrub brush to remove all mould and then rinse the area with clean water. Repeat as necessary until all mould and mildew are gone.
Fill a caulk gun with tub and tile caulk. If possible, use a product that contains a fungicide, which will help to stifle mould growth. Cut a small hole (about ¼ inch diameter) in the top of the caulking tube at a 45 degree angle, and then stick a long, thin nail through the hole to break the inner seal, allowing caulk to flow.
Spread a thin bead of caulk into the joint around the shower faucet, holding the gun at a 45 degree angle to make sure the caulk penetrates the joint. Keep the hole of the caulk gun flush against the wall of the joint for optimal spreading.
Dampen a paper towel and wrap it around your pointer finger. Run your finger along the length of the joint, pushing the caulk firmly into place. Apply more silicone as necessary and smooth until the joint is completely full.
Wipe off any excess silicone with a damp paper towel. Allow the silicone caulk to dry for 24 hours before using the shower.
If you do not kill mould and mildew before applying new silicone, the mould will erode the new sealant.
Never combine ammonia and bleach, even if it's only in small amounts on the wall of your shower. The combination produces toxic fumes.