Say Goodbye to Moldy Shower Caulk with These 3 Easy Fixes

Due to high humidity levels, mold can sneakily build up in bathroom corners and crevices. Porous surfaces in the shower, such as grout and caulking, are especially vulnerable to mold and mildew growth. Caulking is a mold magnet even though its purpose is to be a moisture sealant. If it wears down or cracks over time—or if it was improperly installed to begin with—it loses its ability to be waterproof.

The good news is that it’s a relatively easy fix. As with cleaning grout, removing mold requires just a handful of household ingredients. Learn how to remove mold from your shower caulking (or replace it if necessary) and see how to prevent it from accumulating in the first place.

What Causes Mold to Grow in the Shower?

Mold has the potential to pop up anywhere in your home that has high levels of humidity and moisture. So it’s no wonder that bathrooms, and the showers and tubs within them, are susceptible to mold growth. In the case of caulking, there are several factors to consider.

Other than its repeated exposure to water when the shower is in use, moisture can collect onto caulking and linger long after you’ve turned the faucet off. Soap scum and other residue (both from your body and the products you use to clean it) may also stick to caulking and act as food for mold. If you notice gaps in the caulking or if it’s begun to peel away from the tile edges, there’s a good chance mold is hanging out just under the surface (if it hasn’t seeped through already). Although it’s unlikely, there is the possibility that standard caulk (which is not moisture- and mold-resistant) was used when sealing the shower. If you know for sure that it was or even suspect it, consider swapping it out for mold-resistant caulk using our tips below.

How to Remove Mold from Shower Caulking

There are two easy solutions to kick caulking mold to the curb, but, as always, safety comes first. Before attempting either method, ensure the bathroom is adequately ventilated by turning on the exhaust fan and, if available, opening a window. Consider wearing rubber gloves, especially when using bleach. Also, never attempt to combine the two methods, which use vinegar and bleach, respectively, as mixing the two chemicals will release toxic fumes that can be dangerous.

Method 1: Remove Mold with Vinegar

While vinegar isn’t ideal to use on unsealed grout, it’s safe and effective on silicone caulking. It’s also one of the most successful (and all-natural!) ways to combat mold. Simply fill a spray bottle with white vinegar and generously apply it to the caulking where mold appears (being careful not to get too close to any surrounding unsealed grout). Leave the vinegar application for at least one hour, allowing it to kill spores. Then, go in with a small, soft brush (an old toothbrush can do the trick!) and scrub until the mold disappears. Rinse the caulking and then wipe it completely dry using a clean cloth.

Method 2: Remove Mold with Bleach

For more pervasive or stubborn stains on shower caulking, bleach can serve as an extra powerful mold killer. Dilute bleach with water in a spray bottle and use it to saturate the moldy spots along the caulking. Let it sit for approximately thirty minutes before following up with the same scrubbing, rinsing, and wiping process as you would with vinegar. If mold persists after using either the bleach or vinegar method, repeat the process.

Method 3: Replace the Caulking

Once shower caulking begins to show wear and tear, or if it was poorly applied from the start, it’s nearly impossible to prevent mold from growing. Even if you regularly clean visible mold and mildew on the outside of the caulking, you can still be breathing in the invisible spores. The best thing to do in this case is to completely replace it, but, fortunately, it’s a simple and inexpensive project.

First, remove the old caulk and thoroughly clean the area underneath, using either vinegar or bleach. Once it’s dry, use a caulk gun to apply new mold-resistant silicone caulk along all the edges of the shower. While most caulk will dry in under two hours, it can take up to two days to fully cure, which is vital if you want it to be waterproof (which you do). Keep that in mind when planning this project, especially if you’re working on your home’s one and only shower.

How to Prevent Mold in the Shower

To minimize the amount of mold growth and the time spent cleaning it, make the following habits part of your daily bathroom routine.

• Keep the shower dry when not in use. Remove excess water by wiping the walls with a squeegee or a towel, paying extra attention to areas with caulking, after every shower.
• Maintain appropriate ventilation and humidity levels in the bathroom. Check to ensure fans are working correctly, and always run them when showering. If your bathroom gets excessively humid (and you don’t want to give up your steamy hot showers), consider cracking a window or adding a dehumidifier.
• Clean the shower routinely. Sticking to a regular bathroom cleaning schedule will help prevent mold buildup by addressing the residue that feeds it. Furthermore, cleaning the shower often provides the opportunity to inspect caulking for cracks. Catching them quickly might make the difference between repairing small areas of damage and replacing the entire caulking.