Remove Old Caulk

• If the bathroom fixture has been installed for years and caulk needs to be reapplied, the first step is to remove old caulk from the joint between the fixture and the surface it is installed on. Make sure the area is entirely dry before you begin removing the old caulk so that no water can seep in between the fixture and the wall or tile. Use a putty or utility knife to scrape away the old caulk from the edge of the fixture, cleaning out all of it, because new caulk won't adhere to the old caulk. If possible, remove the entire fixture, such as a sink faucet, to clean the old caulk off before applying the new caulk. If you have just installed the bathroom fixture, there is no need for this step.
  
  

Correct Caulk

• There are several types of caulk, but only a few which can be used in the bathroom. Do not use latex caulk because it will dissolve with constant exposure to water and allow it to seep into your fixture. Acrylic latex can be used in bathrooms, as it is a bit more flexible and expensive than straight latex. Most have fungicide additives that keep mildew or other fungus from growing for up to 15 years. Silicone caulk is the most expensive of the bathroom latex and comes in anti-fungal versions as well. These caulks are the best for bathrooms, but they dry incredibly quickly and require a steady hand to properly apply.
  
  

Applying the Caulk

• Once the joint is clean and dry and you have chosen the right kind of caulk, simply run a bead of it into the joint with your tube of caulk or with a caulking gun. While this may seem simple, there are a few tips that can help you out. The caulk should be at room temperature, which should be warm, about 70 to 75 degrees F. This makes the caulk more malleable and easy to spread. Use a plastic spoon, Popsicle stick or store-bought caulking tool to help smooth the bead of caulk and remove any excess. You can also smooth it with your finger. Make sure you have a number of clean rags on hand to wipe up any caulk that gets on the wall, floor or fixture before it dries.