The other day I decided that I’d had it with watching the caulk around my bathtub keep cracking and slowly grunge-ify. I was going to recaulk the tub myself.
Bathroom caulk that cracks is not only ugly but also it is dangerous. Mildew and mold can easily grow in the gaps, but worse, it can then colonize the walls behind the bathroom. Plus water that seeps in the gaps of cracked caulk can cause rot and structural damage.
Re-caulking the bathroom might take a bit of time. It can also cost you a few dollars in supplies, but in the end, preventing structural damage and health hazards is well worth the small hassle.
In this post, I’ll explain why your bathroom caulk is cracking, what kind of caulk you should be use in the bathroom and how to reapply bathroom caulk so that it will last.
Why Your Bathroom Caulk Keeps Cracking
There are several common reasons that bathroom caulk cracks:
- You used the wrong kind of caulk. By wrong, I mean either your caulk is made of the wrong material, the caulk you’re using is old, or the brand just isn’t high enough quality. (The highest quality caulks are only about $10.) For the bathroom, you need a new, high-quality caulk that is flexible and waterproof.
- You applied new caulk over old caulk. This is a no-no and can lead to cracking. You always need to clean out the old caulk before applying the new.
- Your house is settling. Wood in a new house may be shrinking or the floor in an old bathroom is moving. If this is the case, see tips at the end of this post for applying caulk in settling bathroom.
Caulk vs. Grout: Know the Difference
I have to admit that it wasn’t long ago when I used the terms “grout” and “caulk” interchangeably. But it’s critical that you know the difference between the two, when it comes to preventing your caulk from cracking.
Grout is cement-based. It’s used between tile, and it’s not designed for any movement whatsoever. When used in the bathroom, most grout will need to be sealed annually to stay waterproof.
Caulk, on the other hand, is designed to be flexible and the type made for the bathroom is waterproof. You usually will have caulk running around the rim of your bathtub and other bathroom fixtures, in order to prevent water from seeping into floors and walls. When someone fills the tub with water and gets in for a bath, the caulk should be flexible enough to accommodate the change in weight inside the tub.
Don’t Use Grout and Caulk in the Same Place
Ideally, you will use grout to fill in the gaps between tiles, but you will leave an empty 1/8″ margin at the bottom edge of the tile for any caulking. For example, a tiled walk-in shower would have grout between all the tiles, but at the perimeter where the bottom of the tiles meets the shower bed, there would be no grout at all. This would be the spot for adding caulk.
Types of Caulk
There are many types of caulk on the market, and each one is best for a specific use. For example, acrylic latex caulk is best for filling in holes on baseboards and molding. Try expandable foam caulk to fill holes left by pests on the exterior of your home. Or try rubber caulk on exterior gutters and siding.
In the bathroom, there’s one type of superior caulk and that’s one hundred percent silicone sealant. Technically speaking “sealant” is a more flexible, stretchy, respondent type of caulk. So you definitely want a silicone sealant that’s specifically made for the bathroom. Check the label to be sure it says something like “For Kitchen and Bath” or “For Tub and Tile”.
Silicone Sealant for the Bathroom
You can also find 100% Silicone Sealants that have a mold-resistant formula. That seems like the best of both worlds! The last thing I want is bathroom mold.
But if you already see some growing or you suspect it’s there, be sure to read Bathroom Mold: A Battle Plan to Destroy It. This post has tips that can literally save you thousands of dollars down the road.
As for sealant, I recommend the Advanced Silicone Sealant for Kitchen and Bath from GE. First of all, it worked magic in my bathroom—the improvement in looks is huge! Second, it dries in 30 minutes. (This product is made to use with a caulking gun. You can tell because of the shape of the base. If you plan to hand-squeeze caulk, it will come in a toothpaste-type of tube.)
This silicone sealant comes in clear, white or almond color.
Back in the day, you could only get silicone sealant in a clear color. But now you can find it in all kinds of shades. Plus there is also paintable silicone sealant.
However, Bathroom Designer Kathleen Finley advises going with the color of the nearby tile grout or a clear, but not introducing a third shade. In most cases, you don’t want your caulking (or grout) to be the focal point of your bathroom design.
Cracked Caulk: Are You Sure?
I have two bathrooms in my house. The downstairs bathroom caulk was really getting nasty. It had black specks on it that I am convinced were mold. I could also see the gaps in strips of caulk with my naked eye, so I’m sure water got in there and that’s how the colony began.
Then just last week in my upstairs bathroom, I noticed a dark spot on the caulking. I really couldn’t see a crack in the caulking, though, but I knew there could be a crack under the spot which wouldn’t wipe off.
So I decided to try a mold removing product to see if the stain was on the surface of the caulk or if it was deep inside it. I
Get a Better Look at the Problem
It took about a minute to wipe a mold cleaner on the caulk. I left it on overnight. In the morning, when I wiped it off, the black stain (whatever it was) had completely disappeared.
Well, that was super easy and super awesome!
Also, with the stain gone, I could see the caulk beneath it clearly, and there weren’t any cracks. It turned out that the caulking in my upstairs bathroom was fine, but I wouldn’t have known, if I hadn’t used the mold remover.
Here’s the product I used to remove the stain:
How to Remove Old Caulk
Okay, like a dummy, I tried to remove the caulk in my downstairs bathroom without softening up the old caulk first. Why? Because I didn’t have the right solution on hand, but I really wanted to move forward with my project.
I had to work up a huge sweat and spend at least an hour getting off the old caulk.
Once that part was done, the rest of my project only took about 20 minutes.
If you’re going to recaulk your bathroom, put on your rubber gloves. Then follow these directions for how to easily remove old caulk and add the new. It’s definitely worth it, as new caulk can make a huge difference in the overall appearance of your bathroom:
Step 1: Soften the Caulk
You need to soften the old caulk before you try to remove it. Unless you want to work up a sweat and spend much more time than necessary like I did.
To soften up caulk, there are a few options:
- Try a heat gun on low to soften up old caulk. (Don’t use a plumbing torch).
2. Use a caulk softener. This will run you less than $5 and will make the job a breeze.
Step 2: Remove Caulk with a Utility Knife and Scraper Blade
Once the caulk is softened, you’ll simply run your utility knife horizontally along the top and bottom edges of the line of caulk. Then you can use the scraper to pull it out. Just be careful not to scratch your bathroom fixtures or any tile in the process.
Step 3: Clean the Surface with Rubbing Alcohol
Dampen a cloth or paper towel with rubbing alcohol. Then wipe down the area where you removed the old caulk. This will get any residue left so that the surface is truly clean and the new caulk can adhere to it.
If you notice that you are getting a sandy residue on your paper towel, this may be because there was grout beneath the caulk. Make sure to leave the grout in place. (Ideally, there wouldn’t be grout there, but if it’s old and hard, you should be fine.)
Step 4: Mark Off the Area With Painter’s Tape
You are going to run two parallel lines of painter’s tape, leaving a gap ⅛ – ¼ inch for the caulk between the two lines of tap. For example, if you are caulking the joint between the bathroom vanity and the vanity backsplash, run one line of painter’s tape along the edge of the vanity and one along the vanity backsplash.
Step 5: Prepare Your Caulk Gun and Caulk
You can freehand the application of caulk if you really do have a steady hand. But if you’re like me, and you could never cut a straight line with a pair of scissors, definitely get a caulking gun. I use the Newborn Drip-Free Gator Caulking Gun. It’s really light and easy to handle.
First, take off the cap on the caulk. Then snip off the end of the tube. This is important: Snip at an angle.
Most caulking guns have a piercing rod. This is a long thin piece of metal–about 6 inches and narrower than a pencil–attached to the side. You can pull this out from the caulking gun and stick it into the top of the snipped nozzle and it will go through the seal. Then flip the thin metal rod back into place alongside the caulking gun.
Next, stick your tube of caulk into the caulking gun. Squeeze the first bead of caulk out onto a piece of paper towel. (This is just in case the piercing rod was dirty. You want to be sure the caulk you use is clean.)
Now you’re ready for action!
Step 6: Run a Bead of Caulk Between the 2 Pieces of Tape
Start on one end of the tape. Squeeze the handle on the caulking gun and run a bead of caulk along the thin gap you left between the two pieces of tape. Try not to go back and forth over the same spot multiple times.
The bead of caulk will be thicker at the beginning and then narrow as you proceed. You can add another bead along the way if you need to.
Step 7: Smooth the Caulk
There are a few ways to smooth out the line of caulk. But whatever method you choose, you want to do this quickly, before the caulk starts to harden. Here are some options:
- Wrap your pointer finger in a thin (not plush) damp cloth. Then run your finger down the line of caulk.
- Run your bare finger down the line of caulk.
- Use a plastic spoon. (This is my favorite option!) Hold the handle and drag the spoon down the line, using the scoop to level out the caulk you just applied.
Step 8: Let Your Bathroom Caulk Dry
Every brand of caulk is different, so be sure to check the drying directions on the tube. You don’t want to use any water near the caulk before it’s fully dried.
Tips for Bathroom Caulking Projects
Here are a few tricks to make your bathroom caulking project easier:
How to Prevent Clogged Drains While Caulking
If you’re removing caulk around a bathroom vanity or sinks, bathtub or walk-in shower, plug the drain so that the “shavings” don’t clog it and give you a whole new problem. Once you’ve scraped off the old caulking, remove the shavings with a wet cloth or a Dustbuster before you open the drain again.
How to Make a Neater Caulk Application
When you snip off the tip of the caulk tube nozzle, cut close to the end–and always at an angle. This will give you a narrow bead of caulk. You can always snip off more to get a wider bead, but if you snip off too much of the nozzle, you can’t go back and make the bead narrower.
How to Apply Caulk in a Settling Bathroom
If you suspect your bathroom is settling, then when you caulk around the sink or tub, fill them with water first. When water is in the tub or sink, the joint around these fixtures is wider. You want to caulk the widest version of the joint, rather than the narrowest.
When to Recaulk
Many silicone sealants claim to last up to 10 years. However, many contractors agree that 3-5 years is a more accurate estimation. But even if it hasn’t been 3 years yet, if you’re looking to put your house on the market, recaulking bathroom fixtures is a very easy way to improve the appearance of a bathroom without much money or time invested.
Rotted Drywall or Hidden Mold? Gulp!
Maybe you’ve ignored the cracks in your caulk for years. Do you suspect that the drywall in your bathroom is already rotting, or that you could have hidden mold growing deep inside your walls or ceiling?
Use a moisture meter like the MMD4E to find out the truth without destroying anything. For less than $25, this simple device will give you an instant digital reading of the extent of any moisture damage or leaking that’s not visible to the naked eye. And the great news is that you won’t have to tear into your walls or ceiling to get the answer.
This digital moisture meter will work on wood or drywall anywhere in your home, allowing you to prevent massive mold problems before they escalate.
Repeated Cracking of Bathroom Caulk
If you repeatedly face caulk that’s cracking in the exact same joint, make sure that the old caulk is fully removed and cleaned. Next, try a different brand of caulk and be sure that the bottle you use is new.
If you’re trying to fill a joint wider than ¼” you may need to use a foam backing.
Have you tried all the tips in this post and your bathroom caulk is still cracking? Then it’s probably time to call a contractor for professional help.