10 Effective Ways to Prevent Mold on Baseboards

Giovanni Valle is a licensed architect and LEED-accredited professional and is certified by the National Council of Architectural Registration Boards (NCARB). He is the author and managing editor of various digital publications, including BuilderSpace, Your Own Architect, and Interiors Place.

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Mold on your baseboards can be an indicator of bigger problems behind and inside the drywall, so it is wise to address mold problems before they become serious business. Mold isn’t just unsightly and damaging: it also poses a significant health hazard.

Luckily, there are plenty of ways you can keep your baseboards free from mold. Many of these tips are easy maintenance tasks that can easily fit into your regular household chores.

Inspect Baseboards and Walls Regularly for Signs of Mold

Mold can be difficult and expensive to eradicate once it gets a foothold, so a large part of preventing mold on baseboards is to check them often to make sure that none is developing. The presence of even a small amount of mold can be a sign that bigger problems are on the horizon. So, if you find any mold, it needs to be removed immediately.

Here are some of the signs you should look for when searching your baseboards for mold:

Discoloration on the baseboards or walls around areas that are humid or exposed to moisture
A damp smell of mildew
“Bubbling up” of plaster, sheetrock, or paint

There are over a dozen common types of mold that are found in water-damaged buildings and humid interiors. Some of these molds—such as the notorious Stachybotrys or black mold—are very dangerous to human health. (Source: Aerin Industries) They are especially a hazard for children and people with compromised immune systems, such as cancer patients or people with HIV. Even perfectly healthy people can fall prey to serious organ infections as the result of breathing in mold spores.

If you see a spot on the wall or baseboard that appears discolored as if it might be contaminated with mold, a surefire way to tell is to take a cotton swab and bleach the area. If the area lightens immediately but darkens again a few days later, you have a mold infestation.

This is a sign that the mold has re-invaded the area that you sterilized, and the growth of the mold on your wall or baseboard is aggressive. Therefore, it should be treated before it gets worse.

It’s also important that you make a point to look behind large appliances when inspecting your baseboards and walls for mold. It is easy to forget about these hidden areas both when inspecting your house and cleaning it. Since these areas tend to be magnets for both moisture and darkness, it is essential to check them for mold regularly.

Once you’ve inspected all of the baseboards and found no evidence of mold, you should clean them carefully with a bleach solution to prevent future mold growth. However, if you do find signs of mold, you may have to consider bringing in a professional to remove it.

Keep the Humidity Level Low to Prevent Mold on Baseboards

A huge factor in mold growth on baseboards and walls is ambient humidity—which is the amount of moisture that is in the air. Even if you don’t have leaks into a room that could affect the baseboards, just a high amount of humidity can encourage mold growth. This is especially true in households that use humidifiers or have aquariums.

Dehumidifiers should be used in areas of the house that tend to have high humidity levels, such as basements or rooms that contain aquariums or water features such as fountains. A dehumidifier can help to keep the humidity in the room lower, inhibiting the growth of mold and mildew. This is even more important in climates that are already hot and humid.

Keep the Temperature Controlled to Inhibit Mold Growth

Another way to prevent mold growth in your home is to make sure to keep the temperature indoors cool. Mold grows best between 77 and 86 degrees Fahrenheit. (Source: Wet and Forget) Therefore, indoor areas that are hot and humid, such as kitchens, bathrooms, and basements, are the biggest culprits when it comes to mold growing on the baseboards and walls.

Keeping the air conditioning in your home set at 72 degrees Fahrenheit or less can help lessen the growth of mold in your home (and on your baseboards). If you don’t have air conditioning, you’ll need to keep a closer lookout for mold growth during summer months. This is especially true if you live in a climate that is hot and humid, such as the Southeastern United States.

Dry Any Wet Areas Near the Baseboards Immediately to Prevent Mold

If you find a leak (say the water heater in the basement busts or you have an aquarium break) and you end up dumping lots of water on the area near the baseboards all at once, you must do damage control immediately to prevent the onset of mold. Mold can begin to develop within 24 to 48 if an area isn’t sufficiently dried. (Source: Consumer Reports)

Even if it appears that all the water has been dried with a visual inspection, once water soaks into the plaster or the floor of a house, there can be a lot of hidden water damage. In some cases, you may even have to pull up carpeting or sub-flooring and replace it to prevent the growth of mold beneath the flooring or in the walls.

If your baseboards have been soaked in water for more than 48 hours, then they should probably be pulled up and replaced since wood is porous and even painted wood can take up moisture and begin to rot. Once the baseboards begin to decay, mold will be introduced to the walls and floor areas.

The biggest problem with ignoring a potential mold infestation is that with the speed that mold grows, a small spot of it can spread completely across the interior of a wall or the backside of a baseboard in just a few weeks.

Drying out a flooded basement or room can be done with industrial-strength fans, shop vacuums, and other tools, but if you don’t have access to these kinds of tools, it may a good idea to bring in a flood remediation expert. These professionals can quickly assess the damage the water has done to your baseboards and determine what steps to take to move forward and prevent further damage.

Be Wary of Aquariums and Mold Growth

Aquariums are a beautiful focal point to add to any room, but they can accidentally introduce mold to the baseboards in a room in a couple of different ways, such as:

Increasing the ambient humidity of the room, keeping it consistently above 60% humidity. This increase in humidity is caused by the introduction of moisture to the air from filtration and aeration systems on an aquarium.
Introducing a possible source of water leaks. If check valves are not installed in an aquarium’s tubing systems or if an aquarium develops a broken seal, this can lead to the aquarium dumping several gallons of water onto the floor at the aquarium’s base. Since aquariums are usually placed up against a wall, this often involves the baseboards, too.

That isn’t to say that you shouldn’t keep an aquarium in your home to prevent mold, but if you do have an aquarium, it’s a good idea to install dehumidifiers in the room the aquariums are placed. Also, make sure that all aquarium tubing has check valves installed to prevent the water from being accidentally siphoned back out of the tank in case of an air pump failure.

Ventilation Helps Prevent Mold on Baseboards

Not only should you keep the rooms of your house dry and cool to prevent mold, but you should also keep them full of fresh air. Good circulation and airflow can significantly reduce the chance of mold building up in your living space, as mold prefers to grow in stagnant areas that don’t have much ventilation.

Along with installing fans and other devices to keep the air moving through a mold-vulnerable space, you should also be sure that any furniture and appliances are pulled far enough away from the wall to allow sufficient airflow behind them. Without this airflow, mold has a much greater chance of forming, especially since these areas tend to be dark and humid as well.

Use Mold-Inhibiting Paint to Prevent Mold on Baseboards

Mold-inhibiting paint is a great way to prevent mold from ever forming on your baseboards in the first place. By painting your baseboards with mold-resistant paint, you’re effectively setting up a barrier that prevents mold from growing on your baseboards and spreading anywhere on the floor up into the walls through the baseboards, even if they become wet.

There are also paint primers that contain fungicidal chemicals that can not only prevent new mold from forming; they can also effectively kill any existing mold that may be present even if it’s invisible to the naked eye.

Remember, before painting your baseboards with mold-inhibiting paint, you should sterilize them thoroughly with bleach and then let them dry completely before painting. Mold resistant additives can also be added to traditional paints to give them fungicidal properties, too.

Mold-resistant paints are an especially good idea for using on baseboards in areas of the house that are prone to excess moisture, such as bathrooms or the basement. By putting in a protective buffer against mold in the paint itself, you’ll have much less to worry about.

Here are some of the mold-inhibiting paints and primers that are currently available on the market:

Painting your baseboards with mold-inhibiting paint is one of the best ways to prevent the growth of mold and mildew before it even starts.

Keep Your House Clean to Prevent Moldy Baseboards

This might seem like one of the more obvious tips in this list, but a big part of keeping mold from taking hold of your baseboards is to make sure that your baseboards are clean! Allowing a build-up of grime on the baseboards and walls can eventually strip the paint from them and leave vulnerable areas for mold to develop and grow.

All of the baseboards in your house should be scrubbed with bleach 2-3 times a year. Some good times to do this are during spring cleaning and while winterizing the house before the holidays. That way, not only do you avoid having your baseboards taken over by mold, but your house also can stay clean all year round!

Other ways to keep your house clean and avoid mold is to change out air filters frequently and to vacuum the carpets regularly using an anti-allergy vacuum with a HEPA filter. (Source: National Allergy) These vacuum cleaners help take up and remove the spores of mold that might otherwise have a chance to establish themselves somewhere.

Watch Your Houseplants to Avoid Mold

Even though they can help keep the air in your home fresh, houseplants can also be a source of mold. Not only do they introduce moisture to the environment (and the risk of leaks) by requiring regular watering, but they are also usually kept in potting soil that is practically designed for breeding microbial and fungal colonies.

These colonies—which are beneficial to the plants—can sometimes spread beyond the pot, so it’s important to maintain your houseplants carefully to avoid problems.

Here are some tips for keeping your houseplants from contributing to mold in your walls and baseboards:

Change out the soil. Be careful repotting, as it can stress the plant if done incorrectly, but old soil should be removed periodically and new soil added to prevent the build-up of fungus in the substrate of your houseplants.
Choose soil-less houseplant systems. Many houseplants such as pothos vine can be grown in a vase of water alone, reducing the need for mold-inducing soil. Some plants grow without a soil substrate, such as orchids and air plants.
Remove any dead or dying leaves. Mold is attracted to decomposing plant matter and can set in on leaves, where it may transfer spores to nearby areas if left undisturbed. Check your houseplants once a week and remove any dying leaves or other signs of decomposition to avoid a mold infestation.
Don’t use a humidifier for your plants. If you have houseplants that like high levels of moisture, you might be tempted to install a humidifier to keep them comfortable. But this can introduce mold-loving levels of moisture to the ambient air. Instead, mist plants with a spray bottle to keep them moist and reduce the amount of excess moisture in the room.
Water plants outdoors and let them drain completely before bringing them back in. Lots of houseplant-related links result from the pot leaking from the bottom during excess watering. By watering houseplants outdoors and letting them catch some sun before bringing them back, you can remove excess moisture you’d otherwise be bringing back in with them.

If you’re worried about houseplants potentially causing mold on your baseboards from added moisture or soilborne fungus, you can always choose plants that thrive on a bare minimum of water, such as cacti.

To Prevent Mold, Fix Leaks as Soon as Possible

Often when people discover that they have a leak in the basement or that an area of the house is developing condensation, the repair of these areas can get pushed to the wayside. Sometimes, people procrastinate these fixes because the problem only presents itself during certain times (such as a basement flooding in heavy rains) or because the problem is only intermittently apparent.

However, the leak must be professionally diagnosed and repaired immediately as soon as it is discovered or suspected. Otherwise, the leak may grow larger to the point that a pipe bursts or you may begin to see water leaking out of a ceiling or wall.

While it might be tempting to put off repairs of a house leak until you have some money put aside for them, you should instead have money set aside for emergent household repairs such as this. Mold grows so quickly that even a delay of just a day or two can have lasting negative consequences.

Mold Prevention in Baseboards Comes Down to Maintenance

While mold is a common problem in some areas of the home, it doesn’t have to be. There are plenty of methods and materials available to help homeowners avoid bringing mold, mildew, and other dangerous contaminants into their living spaces. Just keeping the space sterile, dry, and cool can go a long way towards inhibiting mold growth in the home.

Some minor cases of mold can be cleaned and remediated at home with a deep scrub and some bleach, but the problem is that a few signs of mold on the baseboards of the house can speak of worse problems behind the walls. Therefore, it’s always a good idea to seek the opinion of an expert if you think that your mold problem might be bigger than you can handle alone.