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A musty smell coming from the basement is not only unpleasant, but it’s also a sign that potentially dangerous allergens like mold and mildew are likely present. In fact, a survey conducted in 2019 by the U.S. Census Bureau and the U.S. Department of Housing and Urban Development found that of the 124 million occupied households in the U.S., as many 3.7 million reported mold in the previous 12 months.
Even if you regularly and thoroughly clean your home, smells caused by mold or mildew won’t go away until the fungi—and their source—are eliminated.
What causes musty basement odors?
Mold and mildew spores drift through the air until they find a damp, dark, and warm environment—conditions commonly found in basements—that allows them to multiply and thrive. “Basements are naturally cool and warm,” says Josh Mitchell, a plumbing technician and founder of PlumbingLab, an online source for plumbing information. “Humid air can condense on cold walls, creating a breeding ground for mold and mildew, common sources of musty odor.”
As part of the natural metabolic processes of growing and reproducing, molds and mildews release airborne microbial volatile organic compounds (VOCs), chemicals that can produce a characteristic musty odor.
Consequences of Mold
Although most mold species found inside homes aren’t harmful to humans, some people are allergic to the spores. They can develop symptoms that include a stuffy or runny nose, headache, fatigue, coughing or wheezing, and itchy or runny eyes after spending time in a mildewed or moldy room. Stachybotrys chartarum, commonly called black mold, is linked to more serious symptoms, including chest tightness and difficulty breathing, a burning sensation in the nose and throat, dizziness, headache, and trouble concentrating. Luckily, black mold isn’t nearly as common as the less-toxic types.
Mold fungi feed on organic materials, which include wood, many types of fabric, paper, and even some glues. Given enough time, mold can heavily stain walls, floors, and ceilings; decay wood studs and drywall; damage carpets; and eat away at wallpaper. Mold that’s reached this level requires the services of a professional trained in mold remediation, but you can easily deal with a simple case of funky mildew smell and mild mold staining yourself.
How to Fix a Musty-Smelling Basement
While you might be tempted to mask the odor with air fresheners or room sprays, these measures aren’t long-term fixes. Simply masking the odor won’t solve the underlying problem that’s causing the musty smell. To really conquer the stink, it’s best to tackle the stink at the root.
Clean all patches of mold or mildew.
After inspecting the basement for signs of mold and mildew, make a plan to clean away the odor-producing mold and mildew. Here is an effective strategy:
- Mold thrives on paper, so get rid of any moldy or soggy cardboard boxes or other papers you’ve stored in the basement. Pack away salvageable holiday decorations and other items in large plastic containers with securely fitted lids.
- Wash and dry garments on the hottest settings that are safe for the fabrics.
- Trash stinky upholstered furniture, but try to clean any lightly affected pieces with spot treatment.
- First, vacuum the item (discarding the filter and bag when you’re done).
- Then wipe it down with a clean sponge dipped in a mixture of equal parts water and rubbing alcohol.
- Let it air dry outdoors in a sunny spot for several hours—UV rays kill mold spores.
- Next, tackle any spots of mold on the walls, ceiling, or floors with bleach.
- Mix four parts of water to one part of household bleach.
- Take a stiff cleaning brush to the surface.
- To really be thorough, clean all surfaces, whether you see patches of mold growth or not, because microscopic spores could be present.
- After the surfaces are clean, use a clean sponge to wipe them with clean water.
- Then let them air dry.
Dry out the area.
Drying the basement is essential for long-term success. “This step is important for preventing further mold growth and eliminating musty odors,” says Mitchell. He suggests a two-pronged approach:
- Increase ventilation: If possible, open windows “to allow fresh air circulation and moisture to escape,” Mitchell suggests. “Run fans, strategically placed to maximize airflow throughout the basement.”
- Dehumidify: You may be wondering: Will a dehumidifier get rid of musty smells in basements? But, the answer is no, not on its own. A dehumidifier helps dry out the basement space, Mitchell says. Since it’s a tool that’s used to dry out dampness, it comes in handy later, as we will get to it in a minute.
Neutralize the musty smell in the basement.
To remove any lingering musty smell, try the old-fashioned and effective remedy of setting out a few small bowls of baking soda around the room; baking soda absorbs and neutralizes odor molecules well. Activated charcoal is another excellent odor absorber, according to Mitchell.
“Place bowls of activated charcoal around the basement to help remove the musty smell,” he suggests. White vinegar is yet another odor-neutralizing option. For more resistant smells, it’s hard to beat the moisture-and-odor-absorbing qualities of DampRid, which contains salt crystals.
How to Prevent Musty Odors in the Basement
You must eliminate or mitigate the sources of moisture in order to prevent a recurrence of the mold or mildew that caused the musty odor.
“Regularly inspect your basement for any signs of moisture and address them promptly,” MItchell advises. This will, of course, prevent a musty smell in the basement from developing ever again.
Look for leaks.
First, check for water leaks in the basement that might lead to mold and mildew growth. Two common and easily handled problems are condensation dripping off an uninsulated pipe or water leaking through a basement window.
- Condensation from pipes: Many basements have exposed pipes running along the ceiling or down the walls. If you spot water “sweating” off these pipes, insulate them with foam pipe wrap. The lengths of rubbery foam are pre-cut so you can easily slip them over pipes. However, if the pipe is actively leaking, not just sweating, call a plumber to repair it.
- Leaking windows: If your basement has windows, look for water running down the glass or puddling underneath windows when it rains. If you spot water, remove leaves and other debris that could be clogging the outside window wells. Fill the wells with gravel to help reduce the chance of clogs. Replace old weather stripping and caulk, as well, to seal any small leaks around the window frames.
Mitigate water seeping through the foundation, basement walls, and even soil.
- Cracks in the foundation: If you see water coming through a crack in the basement wall or seeping up from the foundation, the problem is a serious one and outside the scope of the typical homeowner’s DIY abilities. Contact a contractor who specializes in basement repairs and basement waterproofing.
- Moisture seeping through walls: Moisture can also seep through walls, says MItchell, who adds that painting basement walls can help lock in old odors and prevent moisture from seeping through. “Use waterproof masonry paint for concrete walls,” he suggests, “and ensure the walls are completely dry before painting, as trapping moisture behind paint can exacerbate mold problems.”
- Moisture from soil: Moisture from the soil can also come up through the foundation and seep into the room through the basement floor, increasing indoor humidity further. This moisture source is best addressed by a dehumidifier and may require a basement waterproofer.
Wipe out water vapor.
Due to its underground location, your basement tends to stay cooler than the upper levels of your home during warm months. That can be a problem, though, when warmer air from upstairs circulates into the basement. As the warmer air rapidly cools in the basement’s lower temperature, you might see a film of moisture that settles on the basement walls, as well as furnishings or other items stored in the space. If you see moisture on walls or other basement contents, wipe them down immediately, and install a basement dehumidifier.
Use the dehumidifier to lower the humidity level to under 60 percent. Test your basement’s level with a hygrometer, which shows the relative humidity of a room at a glance. The preferred level of indoor humidity for most people is between 30 and 50 percent, while mold thrives with humidity of 60 percent or higher.
Among the several types of dehumidifiers available, a compressor dehumidifier is best suited to basements. These devices reduce air humidity by sucking the room air over chilled coils, causing the moisture to condense into a storage tank.
The post Get Rid of That Musty Smell in Your Basement appeared first on Bob Vila.
