Do you smell that? Whiffs of musty odors are pretty distinctive in the home, and they can come from basements, walls, spoiled food, laundry, or shower stalls. Usually, this indicates that there is a mold or mildew problem.
Fortunately, with a bit of investigation, thorough cleaning with supplies you have on hand, and diligence to prevent further growth, you can easily control musty smells.
What Causes Musty Smells?
If you've ever smelled decaying wood or wet, musty towels left in a pile after a long weekend, you've smelled the stale, earthy odor of mold and mildew. A leaky pipe or roof can also cause the buildup of humidity and moisture that results in this offensive smell. Moisture and still air lingering in dark crevices around your home create a welcoming environment for the growth of mold and mildew. When the spores begin to multiply, they emit gasses that our noses can detect.
Unfortunately, mold spores multiply quickly, and it doesn't take a huge colony to create odors. Promptly clean small areas of mildew (fungi that appear flat on a surface) or mold (fungi that appear raised and usually fuzzy), and monitor the site to prevent return growth.
If the mold area is larger than 10 square feet, you may need professional mold abatement. For small colonies of mildew on fabrics or walls, you can follow these tips to get the source of the musty smells under control.
When cleaning mold and mildew, always take the proper precautions and wear protective clothing, including long gloves, goggles, and a respirator to avoid breathing in mold or mold spores. When cleaning, bag up and put in outdoor garbage all rags and sponges containing mold spores to eliminate spreading.
Are Mold and Mildew Dangerous?
Exposure to mold and mildew in the home can be hazardous to your health. Some people are more sensitive to mold and mildew than others or may already have asthma that mold and mildew can exacerbate. The problem can still cause respiratory and other bodily symptoms of varying degrees that may include:
- Stuffy nose
- Red or itchy eyes
- Itchy skin
- Shortness of breath
Locate the Source of the Musty Smell
It's time to take a look and a sniff around. Until you identify the source of the musty smell, you'll never be able to get rid of it—and it can get worse. Begin your search in areas that are often warm and moist, like a bathroom. Check for mildew growth in the shower, on the shower curtain, and leaks around sinks, tubs, and toilets.
In the kitchen, look for leaks around the sink and dishwasher. Check under and in the refrigerator and small appliances that use water, like coffee makers and tea kettles. Be sure to also check the trashcan, as mildew could be growing under the disposable trash bag liner.
In the bedroom and living areas, look around window seals for leaks and under potted plants that can leak. Check closets for mildew caused by storing damp shoes or clothes.
Don't forget to take a trip to the attic, basement, and garage to check for damp areas around windows, water heaters, and vents.
Check for leaks around the washer and around the doors of front-load washers that can harbor mildew in the laundry room. Be sure that your dryer vent is clean and that the outdoor vent is not blocked, so there is good airflow to eliminate moisture.
Leaks can travel within walls, sometimes originating inside them as well. For example, it is not uncommon for water leaks to start in the attic from an old roof or ice damns and then run down the wall and leak through the ceiling, window frames, or baseboards below.
Summer beach bags and sports bags should be checked, as forgotten wet beach towels, water-logged beach toys, wet sports socks, sport uniform padding and similar items can all cause a moldy mess if forgotten about.
In the kitchen, cabinets and pantries can also cause a problem if a bottle or jar of liquid has knocked over inside.
Repair Leaks and Control Excessive Moisture
To get musty smells under control, repair any leaks that you find. It's the best way to gain control over the odor. In areas with excessive moisture, install ventilation fans, place moisture barriers over damp soil, or redirect water flow on the home's exterior.
Increase Air Circulation
Whether you find visible evidence of mildew or not, a musty smell signals that you need to increase air circulation in the home. Open windows and doors, turn on ceiling and attic fans, or add fans to each room. Starting your HVAC system can also help draw out odors and capture mold spores in the filters. Be sure that the system has clean filters and replace them often to help remove musty smells. It may also be a smart investment to purchase an air purifier if this is an ongoing issue or if anyone in your house struggles with allergies and stronger sensitivity to mold. Air purifiers can make a big difference in reducing the smell and the spread of spores.
Install a Dehumidifier
Since mold and mildew need moisture to thrive, lessening the humidity level in a home can help keep mildew under control. Try to keep your interior humidity no higher than 50%. To gauge the moisture level in your home, get a hygrometer or humidity sensor. Some HVAC systems have dehumidifiers as part of the unit, or you can get a free-standing dehumidifier. Keep the dehumidifier clean and regularly empty the water-collection bin.
How to Clean Mildew
When you see evidence of mildew, it's essential to get rid of it before or after you solve the problem causing the issue. For a minor spot or two of mold, you don't have to use bleach, and you can use a bucket of warm water and a couple of squirts of dish detergent to wipe away the mold spores.
For a more moderate mold area, use bleach to clean up the mold. In a 1 gallon bucket of water, dilute 1 cup of chlorine bleach. This solution effectively kills mildew on surfaces like ceramic tile and grout, cement walls, and washable fabrics.
When using bleach to clean mold, do not mix it (even when diluted) with any other cleaning solutions that contain ammonia because it will cause toxic fumes.
You can also use a more natural approach by spraying the area with distilled white vinegar. Allow the vinegar to work for an hour, and then scrub away the mildew with a sponge or microfiber cloth dipped in baking soda.
You should clean washable fabrics harboring mildew with the hottest water suitable for the material, a heavy-duty laundry detergent, and, for white fabrics, chlorine bleach. Follow the cleaning guidelines for mildewed shoes and dry clean only clothes.
How to Remove Mold
Whatever kind of mold you have, if you have more than 10 square feet of it, the Environmental Protection Agency advises against remediation on your own.
But if you have a small quantity and want to clean it up on your own, you will need a few materials in preparation:
- Protective gear like goggles, rubber gloves, and a respirator/N95-type mask
- A window fan to exhaust the air out of the room; it should stop the spores from settling in the room.
- Wet/dry vacuum to thoroughly vacuum the area to rid it of airborne spores; you can clean the wet/dry vacuum interior afterward.
- Seal the A/C and heating vents to stop spores from traveling; also, turn off the HVAC system
- Trash bags are necessary to remove the mold-covered materials
Fix plumbing leaks and other water problems as soon as possible. Locate the source of the mold. If it's in or on the wall or sheetrock and you have experience changing sheetrock, you can cut out the affected part of the wall. You will need to change out that area of wall insulation too.
Scrub mold off hard surfaces with detergent and water. Dry all items completely. When you’re sure the mold has been eliminated, seal any wood surfaces with a pigmented shellac or an oil-based primer. Repaint cleaned wall surfaces with latex paint that contains a mildewcide to help stop future mold growth.
Throw away any moldy absorbent or porous materials, such as ceiling tiles and carpet. Mold may be difficult or impossible to remove entirely from those materials.
If you can't find the source of the mold, you should call a professional. Or, hire a professional if you think it's hiding under wallpaper and fear that removing it will lead to a massive release of spores.
Get Rid of Musty Odors
- Deep clean carpets and upholstered furniture: Whether you do it yourself or hire a professional, deep cleaning carpet and upholstered furniture can get rid of mildew spores and freshen a home. Clean on a dry, breezy day so that the fabrics will dry quickly.
- Clean and declutter every space: Stacks of papers and books can trap moisture and lead to a musty odor. Clean and dust every surface and dispose of as much clutter as possible in every room.
- Add odor absorbers: Commercial odor absorbers that use activated charcoal are available to hang in closets or spaces that lack good air circulation. Or, use a bowl of dry baking soda, coffee grounds, or kitty litter to help absorb odors, and be sure to change these products frequently.
- Add pleasing scents: Once the mildew is gone, you can add a more pleasing scent by simmering spices or citrus peels, lighting candles, using diffuser sticks, essential oil diffusers, or commercial air fresheners.
Prevent Mold and Mildew
If you know you have a mold or mildew trouble spot in your house, then be proactive. If the bathroom or kitchen is the source of your problem, then clean with mold-killing products. Also, the next time you redo the paint on the walls in the bathroom or kitchen, use mold-inhibiting paints to keep the spores away.
The key to maintaining a mold- and mildew-free home is being diligent. It can be challenging in climates with high humidity or poor ventilation. Still, if you remove the spores, keep surfaces dry, and mechanically provide good air circulation, you can stop it from returning.
Centers for Disease Control. Mold. https://www.cdc.gov/
US Environmental Protection Agency. Mold cleanup in your home. https://www.epa.gov/