Remove and replace old silicone caulk.
Nothing looks worse in a bathroom than old, moldy and discolored silicone. Black spots of mildew in the silicone sealant are unsightly and impossible to clean. The good news is that we can to remove old silicone and update with a new waterproof silicone sealant. Employing the right sealant will help hold back those moldy black spots coming back. It is important to completely remove old silicone. This is because an established mold colony in the old sealant can grow through your new sealant, even if your new sealant has mold inhibitors to prevent this from happening.
1. Cut away the sealant using a sharp blade.
2. Clean the suspected moldy surface with the Clorox solution.
3. Ensure the surfaces are completely dry.
4. Applying a new silicone sealant.