While it might not be the most exciting job in the DIY catalog, removing old caulk is a necessary task if you’re going to apply new caulk to a bathtub, sink, or shower. Once caulk starts to crack and degrade, it’s time to remove it completely and replace it with a fresh bead of new caulking.
Replacing old caulk not only creates a seal that prevents moisture, dust, and air from getting into sensitive places, it also greatly improves the look of any bathroom.
In fact, one of the easiest ways to improve the look of any bathroom is by removing old, mildewy caulk and replacing it with brand new sparkling white caulk. Think of it like painting your exterior window trim for your bathroom!
Let’s take a look at how to remove old caulk in step-by-step detail.
Tools & Materials Needed
- Utility knife
- Razor scraper or caulk removal tool
- Caulk remover chemical (optional)
- Rubbing alcohol
- Stiff bristle brush
Removing Old Caulk – Guide
Step 1: Test Existing Caulk
Before you get down to work, you’ll want to determine what type of caulking you’re dealing with. Make a small cut into the caulking with your utility knife and test how difficult it is to peel away.
Silicone caulking is soft and rubbery, and can normally be removed with less difficulty than other types. Acrylic and water-based caulk are typically harder and more difficult to remove.
If you can peel the old caulking away from the seam without difficulty then you should be able to skip the next step.
Step 2 (Optional): Apply Caulk Remover
This step is not always necessary, but when you’re dealing with particularly stubborn caulk it can make removal much easier. There a number of different products made specifically for this task, just be sure to match the caulk remover to the type of caulking your dealing with.
You’ll want to apply the caulk removal to the entire caulk surface with an old rag or cloth. The chemicals in the caulk remover will cause the caulk to soften and weaken the bond between the caulk and the surface. The longer you leave it, the softer and weaker it will get.
Follow the directions on the bottle, but in general, you’ll want to let the caulk remover sit for at least 3 to 4 hours.
Step 3: Cut and Peel Away Old Caulk
Now, it’s time to get down and dirty with removing the old caulk.
Start by cutting into the caulk with a utility knife. Try to get ahold of a large piece of it and peel it away from the seam in long strips. Removing it like this is easier than scraping it away with a razor.
Use a razor scraper to cut and scrape away any leftover pieces of caulk left on either edge of the seam. Try to get the blade as flat to the surface as possible, so you can ‘push’ through the caulk rather than scraping. Be careful when using a razor scraper against painted surfaces or tile, as it can actually chip and damage finished surfaces.
There are also several well-made caulk removal tools formulated particularly for this task. These tools are purposefully designed for removing caulk without scratching or damaging any surfaces. If you’ve got a lot of caulking to re-do, or you tend to be a little clumsy, one of these can be a lifesaver.
Step 4: Remove Remaining Caulking Bits
No matter how well you peel away the old caulk, you’ll always be left with a few stubborn bits. There are a number of different ways you can remove these, but don’t be tempted to leave them in place. New caulk won’t adhere well to old caulk, so leaving these bits in place can result in a poor quality seal.
How to remove stubborn bits of caulk:
- Soak them in rubbing alcohol for an hour or so. This will start to break down the bonds and make the caulk easy to scrape off.
- Use a stiff-bristled brush or an old toothbrush to scrub away the remaining pieces.
- Use a hairdryer or heat gun to soften the material before scraping it away.
Step 5: Clean & Dry the Entire Surface
Before you can apply a new bead of caulk to the seam, you’ll want to thoroughly clean the surface of dirt and grime. Grime, dirt, mildew, and other nasty stuff has a tendency to collect in the seams of the old caulk, so you want to go a good job removing it.
Use an old rag, toothbrush, or brush to scrub away any nasty buildup. Then use a clean, dry rag or paper towel to dry the seam completely.
If you’ve got some mold or mildew to deal with, use bleach or a cleaning product with mildewcide to kill the mildew and prevent it from coming back.
Now you’ve got a perfectly cleaned and prepped seam ready for a new bead of caulk. All that’s left to do is load your caulking gun and get to work!