How to Remove Silicon Caulking

Silicon caulking makes a great barrier to water penetration because of its flexibility and long life. However, not all silicon caulks are designed for use in bathrooms and don’t contain a mildewicide to prevent mold and mildew growth, so over time it will start looking ugly and dirty. You can clean it, but once mildew starts to grow, it’s very difficult to get rid of it entirely.



In these cases, many folks decide to get rid of their old caulking and install new. Unfortunately, removing silicon caulking can be a chore. However, if you’re up for it, here’s how to remove silicon caulking.

Difficulty: Moderate

Instructions

Things You'll Need:

• Utility knife
• Glass scraper or razor blade holder
• Isopropyl alcohol
• Abrasive pad

1. Check to be sure the caulking you want to remove is actually silicon. Use your utility knife to cut it. If the caulking is soft and rubbery it’s probably silicon, however, if it’s somewhat hard, you’re probably dealing with a latex-based caulk. Assuming your caulk is silicon-based, it can be removed by a combination of cutting, scraping and rubbing.

2. Clean the existing caulking and the surrounding area (tub lip and walls). You want to clean this area before removing the old caulk because the whole area needs to be clean when you install your new caulking. By cleaning the walls now, you won’t have to do it after you've removed the old caulking (and water won't get in behind your walls).

3. Start by cutting through each side of the entire silicon bead with your utility knife, then pull out what you can in a long thread. Be sure to hold the knife blade at a low angle so it won’t cut into your tub or shower pan

4. Use your glass scraper or razor blade holder (again held at a low angle) to scrape away remaining caulking.

5. Soak a plastic abrasive pad with isopropyl alcohol or mineral spirits and rub off any remaining residue of the silicon caulking. You need to be sure all traces of the old caulking are gone, since new silicon won’t stick to old.

6. It’s also a good idea to clean the surrounding area (tub lip and walls) with isopropyl alcohol to be sure your new caulking will adhere to the walls and tub or shower pan.

Tips & Warnings

• Silicon caulking is tough and can be difficult to cut. Make sure your knife blade is sharp and wear gloves to protect your hands.
• Once you’ve removed the old caulking, check that the new caulk you install is formulated for use in bathrooms and resists mildew. If you’re not sure, ask at your home or hardware store.
• When you’re removing caulking you'll likely be bent over in an awkward position. It's important not to rush through the job, so be sure to take time to stand up and stretch out, so your back doesn’t cramp up.
• Some people suggest you try to soften silicon caulk using household oven cleaner applied directly to the caulk. Be aware these products could damage plastic, acrylic or fiberglass surfaces.