Black Mold in the Bathroom? Cleaning Supplies May Not Be Enough

Discolorations in your bathroom’s tile and grout aren’t just unsightly—sometimes they’re downright dangerous. Once you determine which type of mold you’re dealing with, you can wipe it out with the appropriate plan of attack.

By Bob Vila and Evelyn Auer | Updated Oct 6, 2023 3:56 AM

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Mold grows on the ground around a tub floor.

Photo: istockphoto.com

Q: I just went to clean our rental property after the tenant moved out, and I found black mold in the bathroom. Yuck! How do I get rid of it, and how can I prevent it from coming back?

A: Yuck is right! Mold is gross. And depending on which variety it is, it could be dangerous. If the space has been flooded or a long-term leak only recently revealed itself, what you see might be black mold. But what is black mold, exactly? Also called Stachybotrys chartarum, this mold species is an aggressive and highly toxic mold variety that is best removed by a professional.

It can be difficult to tell whether an accumulation of grossness along your bathtub or shower tile is an indication of bathroom black mold vs. mildew or another mold variety. The appearance of black mold can be described as a dark patch that forms in a circular pattern. But the only way to identify black mold for sure is to test it—either by asking professionals to collect samples or sending some away using a black mold test kit—and wait for results. Once you can confirm that it’s the latter, garden-variety bathroom mold type, you can get to work ridding it yourself by learning how to remove black mold.

In general, mold is a fungus that’s plentiful in the natural environment and, when conditions are right, indoors as well. Take the bathroom: Its damp, dark, and often warm interior makes mold growth a perennial problem there. Without adequate ventilation or routine towel-drying after each use, black mold can easily take up residence and thrive. Here’s how to get rid of black mold in the bathroom and prevent it from making a comeback.

1. Remove the mold—either by yourself or by hiring a pro.

Depending on the extent of the mold growth, it may be best to leave the cleanup to one of the best mold removal companies such as ServiceMaster Restore or ServPro. The Environmental Protection Agency (EPA) advises that mold growth that exceeds 10 square feet, is the result of a sewage leak, or is located in the home’s HVAC system be handled by a professional to ensure that the removal is handled safely. Mold remediation costs average $2,254, which may seem steep, but many residents find the cost to be worth it to know that the mold has been removed for good. Residents who are planning on going the DIY route will want to use an antifungal surface cleaner and a sponge or cloth to wipe the mold off of nonporous surfaces like tile and porcelain. They’ll then want to follow up by using a scrub brush on any stubborn areas and thoroughly rinsing with water. This process should remove the mold, even if some dark coloring remains.

2. Take the appropriate safety precautions to protect yourself from mold spores.

A hand in a blue cleaning glove uses a toothbrush to remove mold from grout on a bathroom wall.

Photo: istockphoto.com

Black mold can cause serious health effects after just a short period of exposure. According to the Cleveland Clinic, some of the milder black mold symptoms include sneezing, congestion, coughing, difficulty breathing, and skin rashes. Reactions may be more severe for those with asthma or compromised immune systems. According to the EPA, the best way for residents to protect themselves from the effects of black mold is to avoid exposure, but since removing mold involves being in close proximity to it, it’s a good idea for residents to put on protective clothing and gear before getting started. Wearing an N-95 mask can reduce the risk of breathing in spores. It’s a good idea to cover up with long sleeves and wear gloves to avoid coming into direct contact with the mold. Lastly, it’s also recommended that residents wear goggles that do not have ventilation holes. These measures are likely to provide sufficient protection, but if a resident does notice any black mold side effects, it’s advisable for them to stop working and have a professional take over.

3. Clean surface stains and eliminate mold spores.

For those who are not sure how to treat black mold or don’t know what kills mold, there are a few methods to try. Bathroom black mold is most common in showers, so to remove the stains that mold leaves on nonporous surfaces like grout, they’ll want to mix equal parts of bleach and water in a spray bottle and spray it over the stained area, allowing it to sit for several minutes. Then, they’ll want to return and spray the area again, then use a scrub brush to scrub out any remaining discoloration. An old toothbrush aptly reaches inside grout’s narrow lines. Hydrogen peroxide is also effective for cleaning black mold and can be applied (undiluted) using the same method.

While bleach is superb at removing surface mold, it’s not the most effective way to eliminate the mold membrane. Luckily, vinegar kills mold even more effectively. Residents can simply spray vinegar onto the area and allow it to dry so that it can penetrate any porous materials and take care of remaining mold spores. Residents will want to be advised that mixing vinegar and bleach creates a gas that is highly toxic, so it’s a good idea to thoroughly rinse any bleach from the shower before applying the vinegar.

Vinegar can also be used to treat black mold in bathroom walls since the acid is able to penetrate drywall, which is relatively porous. If the vinegar smell is too strong, baking soda can also work. Residents can combine 1 teaspoon of baking soda with 2 cups of water in a spray bottle and apply it to the wall. They’ll then want to scrub the area and rinse with water before reapplying the solution and letting it dry. Baking soda has the added benefit of effectively neutralizing the smell of mold. Both the vinegar and baking soda methods can also be used for black mold on bathroom ceilings. Residents will want to resist the temptation to paint over mold on walls and ceilings since this merely covers up the problem rather than eliminating it.

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4. Keep plenty of cleaning supplies on hand to prevent future black mold growth.

Residents will want to do a thorough cleaning of the bathroom weekly; if all else fails, this consistent regimen should keep mold spores from taking hold and running amok. They can rotate an antifungal cleaner into the routine at least once a month, and they may want to stock up on some of the best mold test kits to use at the earliest sign of mold, which is when it’s easiest to remove.

To prevent black mold in the shower, residents can use a squeegee to remove water droplets from the shower walls, then towel down glass doors and tile to remove the remaining moisture from those surfaces. It’s also a good idea for residents to dry off shampoo bottles and wipe out sinks after each use, too, so that mold and mildew have nowhere to go (and grow). For good measure, residents can also store a spray bottle of vinegar in the bathroom, then apply it and let it air-dry after every shower or soak. (They might want to add several drops of their favorite essential oil—tea tree, peppermint, or lavender—to the bottle to make the vinegar smell less offensive.) At the first signs of black mold returning, residents will want to give the area a good scrub—the longer the problem is allowed to progress, the more difficult it will be to clean.

5. Control the humidity levels.

If the bathroom doesn’t already have a fan, residents will want to choose an exhaust fan to install. Running one every time they shower or bathe and several minutes following will remove any residual steam and dry the air out. If the home’s washer and dryer are located in the bathroom, it’s also worth the resident running the fan when doing laundry. If getting a bathroom fan isn’t an option, opening a window, running a dehumidifier, or leaving the bathroom door ajar can further help with ventilation.

In addition to wiping down the shower after bathing, it’s important for residents to stay vigilant about water in the rest of the bathroom. Wet floors will need to be wiped up as soon as possible. Mold on windowsills is common due to the accumulation of condensation, so residents will want to wipe away steam on windows and mirrors as needed.

The most enjoyable way to keep moisture levels down is to shop for a few plants that thrive in low-light, humid conditions. Tropical plants such as orchids and peace lilies are some of the best-suited plants for this purpose and can double as charming decor.

6. If in any doubt, hire a professional mold remediation company to get rid of black mold in the bathroom.

In the event that DIY black mold removal methods fall short, or if residents begin to exhibit symptoms of black mold exposure, it’s a good idea for them to let a professional mold removal company treat the home. If the mold growth covers a large area or is the result of extensive water damage, it may be difficult for a resident to know if they’ve completely eradicated the problem. Professionals have the equipment and expertise to return the home to a safe state. They’ll also be able to make recommendations on how to prevent mold from coming back in the future.

If a resident isn’t sure where to start, they’ll want to call a remediation company for a mold inspection. These pros can determine the extent of the problem and let the resident know the best next steps. Mold inspection costs typically fall around $648, but some companies will waive this fee if the customer hires them for remediation services. Black mold removal costs start at about $800 on average, and this is often well worth the peace of mind for residents that comes from knowing their home is mold-free. It’s also worth noting that homeowners insurance may cover mold remediation depending on the circumstances.

Some jobs are better left to the pros
Get free, no-commitment estimates from mold removal experts near you.
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