How To Get Rid of Shower Caulk Mold

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Have a mold problem on your shower walls? While shower caulking is waterproof, it isn't mold-resistant.

Sooner or later, mold spores are going to make a home out of the excess moisture in your shower caulk and bathroom.

Once mold attacks shower caulk or grout, it can be particularly hard to remove. But thankfully, the task to remove caulk mold growing from shower surfaces is not an impossible one with the right method and regular cleaning.

Let's go over what you can do to clean shower caulk and kill mold.

First Things First: Where is the Mold Infestation Growing?

If mold is growing on top of your caulking or grout, consider yourself lucky. Why? Because mold can actually form inside or under grout or caulk.

The reason this can happen is that over time, your caulking may crack. All it takes is a tiny fissure for mold to get underneath.

To figure out what you are dealing with, soak a few cotton balls in bleach, and press them onto the affected area. If you see the mold go away right away, it is probably superficial.

But if 30 or 40 seconds go by and you can still see some black mold, then it is inside the caulk. That is bad news, but you can still stop and proceed with mold removal, even when it penetrates your caulk.

What You Need to Remove Shower Caulking

Exactly what you need to remove mold from shower caulk depends on your exact situation. But for the sake of this post, we are going to assume you need to remove mold growth from under your caulk. We also will be focusing on shower caulking specifically, not grout.

You may already have most of the materials, a cleaning solution, and tools you require on hand. If not, gather supplies on this list for mold removal from your local hardware store.

Tools and Materials

  • Bleach
  • Caulk remover
  • Utility knife
  • Putty knife
  • Water
  • Rubber gloves
  • Grout sealer
  • Caulk
  • Wet towels
  • Toilet paper

How to Remove Mold From Shower Caulk Step by Step

If you assess caulk frequently and the mold problem only affected the top of the caulk, the process described using the bleach should have been sufficient to kill it. But if it is under your caulk, you are going to need to start by removing and replacing the caulk.

Step 1

Apply a caulk remover of your choice to the old caulk you want to get rid of. You will need to wait while the caulk removal product softens your caulk.

The more time you give it, the easier it will be for you to remove the caulk. About 4 hours is ideal.

Step 2

Use a utility knife to scrape away the caulk. If you prefer, you can invest in a caulk removal tool designed specifically for this purpose.

Step 3

Still, some residue left over once the caulk is gone? You can use a putty knife to get rid of what is left. If you do not have one, an old toothbrush is often sufficient.

Step 4

Look for the mold. Do you see it? Is it black or pink mold? You may be able to proceed to the next step. But if you do not, you need to figure out the shower caulk source. Sometimes, unfortunately, that might involve prying out one of your tiles.

Step 5

It is now time to kill the mold from shower caulking. You do not need a special product to do this, just a simple bleach solution. Mix bleach and warm water at a ratio of 1:5.

You can soak cotton balls with this fairly simple remedy and let them sit for a minute over the mold spores. If necessary, you can also try scrubbing the mold with a small brush.

Step 6

It is now time to put everything back. Depending on what you had to do in step 4, that could mean replacing a tile or two and also sealing up your grout.

After that, you can re-caulk or proceed with replacing caulk. Just make sure you are applying the new caulk to a dry surface.

How Do You Prevent Mold in Shower Caulking?

It is great to know how to remove mold from the caulk in your shower–but it is far better not to have to do so at all. After all, every time you need to scrub away mold or remove and replace your caulk, it will take a lot of time and effort.

How can you prevent mold from taking hold in your bathroom to begin with? Is there mold-resistant caulk?

For one thing, make sure that going forward, you are using the right type of caulk. Silicone caulking is ideal for preventing mold. Look specifically for a product that contains a biocide.

For another, make sure that you are properly cleaning and maintaining your caulk on a regular basis. Doing this is necessary even if you have a “mold-resistant” caulk containing biocide.


If you spot cracks in your caulk or grout, seal them before they can lead to more mold underneath your caulk. Wipe away surface mold before it can creep into vulnerabilities in your caulk.

Last but not least, make sure that your bathroom has adequate ventilation if possible. The less moisture you have trapped in your shower, the less inviting it will be for mold or mildew. 

Clean and dry your washroom doors, floors and windows and have proper ventilation.

Depending on your situation, this could entail anything from a minor change in your habits to a major renovation.

Frequently Asked Questions About Cleaning Caulk Mold

Now that you know the basic method to stop mold in your shower, let's answer some frequently asked questions.

Q: How do you remove black mold from shower caulking?

A: The same methods that are recommended in general will work fine for black mold as well.

Q: How do you remove mold from silicone caulk?

A: The method we described above which can be used should work fine on this type of caulk.

Q: Does bleach in a spray bottle really work to kill mold?

A: You may have heard that a bleach mixture is ineffectual for dealing with mold in an affected area. Actually, it can be ineffective on porous surfaces. But in the bathroom, you are dealing with the caulk line, which is non-permeable, and the non-porous surfaces in your shower.

So, using bleach and cotton balls kills mold just fine as long as you wear gloves and other protective gear like eye protection.

But if you do not want to use this method or if it is not getting the job done for whatever reason and there is visible black mold, there are some other ideas you can try.

Q: What are some alternatives to bleach to kill mold?

A: If you are not keen on using bleach, there are a number of other solutions you can consider for getting rid of mold.

One method that can work well is to combine water and hydrogen peroxide in equal parts. You can use a spray bottle to dispense the hydrogen peroxide. Wear rubber gloves as needed if you are cleaning mold this way.

You will need to wait for a little bit while the hydrogen peroxide goes to work and remove mold from shower caulking, and then you can rinse it off.

Another option to remove mold from a shower caulk is to combine water and baking soda. You can try adding just a little baking soda to the water, then spray, wait, and wipe it down. Alternately, you can adjust the ration to make a baking soda paste and use a scrub brush or toothbrush.

Yet another shower caulking removal solution is white vinegar. You do not need to dilute the vinegar with water. Unlike a water solution, you can pour this right into a spray bottle.

Spray the vinegar to remove mold from the shower caulking, and then wait. After the vinegar has had some time to work, you can rinse it off to remove mold spores from the acrylic caulk, bathroom door, or shower tiles.

If you want to enhance your vinegar, you can add a bit of tea tree oil to your spray bottle. Spray it onto the shower caulking and wait before rinsing off the silicone caulking. With all of these mold removal methods, your shower caulk should be just fine.

Q: What if the mold growth is extensive?

A: Hopefully, you will find that you can clean the mold out of your shower yourself using vinegar, baking soda, or one of the other methods in this article.

But you might discover that your mold issue isn't confined to one small spot in your shower. If it covers a more extensive part of the shower, you may need to call in a professional to help you kill mold from shower caulking for good.

Also, if you are currently unable to control the moisture levels in your bathroom, you might need to make modifications to remove growing mold.

You may, for instance, benefit from adding ventilation to the room or upgrading it to remove excess moisture. If that is the case, that could also necessitate calling in a professional. It would depend on how extensive the work would need to be to achieve the result you are looking for. For example, a bathroom fan to aid poor ventilation may require professional help while a much eaaier method is to keep your windows open.

Q: Can I just replace caulking?

Yes, if there is black mold, soap scum, or mildew has built up and your shower caulking has started to pull away from your shower walls, re-caulking is an option.

Shower Caulk Mold Summary

A moist environment is more prone to mold which is usually seen on shower caulking. If your washroom or shower drips, then the first step is to get the plumbing issues sorted. Removing or cleaning mold growing in the tub and shower can take some time and effort, but if you can find the root of the problem, you can prevent more mold growth in your shower caulking in the future.

Kristina Perrin

Kristina Perrin

Kristina is an expert DIY home remodeler and mom to three. When she's not cooking or experimenting with new recipes, you can find her working on new home improvement projects or writing about her favorite kitchen appliances or DIY projects on Kitchen Infinity blog.

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