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Basements are the perfect environment for damp, musty smells caused by mold and mildew. Removing the musty smell from your basement begins with getting rid of the excess moisture from mold and mildew growing in the crevices of your dirt or concrete walls (in unfinished basements) or your drywall (in finished basements). Below are tried-and-true natural ways to get rid of that musty basement smell, plus some tips on how to prevent musty smells caused by moisture.
7 Ways to Get Rid of the Musty Smell in Your Basement
- Throw out everything with mold on it that can't be salvaged, such as old clothes, shoes, boxes, books and papers, fiberglass insulation, or rugs/carpets/soft furnishings.
- Use vinegar and baking soda to kill mold and deodorize at the same time.
- Sand away the mold and vacuum up the dust using a HEPA filter vacuum.
- Pull moisture from the air by using a dehumidifier or desiccant pack.
- Add a window fan to circulate the air in and out the window.
- Place open packets or bowls of activated charcoal in the basement to absorb moisture and foul odors.
- Place bowls of coffee grounds in every corner of the basement. Coffee grounds absorb foul odors.
1. Throw Out the Mold
If mold has damaged porous organic materials, such as boxes, chipboards, books, carpets, or fiberglass insulation, toss them in plastic trash bags and dispose of them right away to prevent further damage. There is no use in cleaning these materials, and it is always better and cheaper to just replace them with brand new stuff.
If your floor joists, floorboards, or drywalls have mold damage, you may be able to save it by cleaning it with a vinegar solution. If the damage is severe, however, it may be more efficient to just replace the item.
For clothes and shoes that are moldy, either dispose of them or wash and dry them thoroughly.
2. Use Vinegar and Baking Soda
If you choose to salvage some things, such as wooden furniture or hardwood floors, take the material outside and give it a good, thorough cleaning with vinegar and baking soda. For floors that have surface mold, you can do the cleaning in the basement, but make sure you open up all windows to allow for ventilation while working.
- Start by spraying infected areas with white vinegar. Studies show that vinegar kills 82% of mold species and removes musty odor at the same time. Let the vinegar absorb the mold for about 20 minutes.
- Using a clean cloth, wipe away the mold. For stubborn mold, scrub the area with a stiff brush and a vinegar solution of about 1/8 cup of white vinegar and 1 gallon of water. Some people also use a borax solution on their floor joists to remove black mold.
- Once the mold is gone, spritz the furniture with either white vinegar or a tea tree oil solution to kill any remaining invisible mold spores.
- Sprinkle floors and furniture with baking soda to further remove the musty smell. For hard-to-reach places, you can also make a baking soda spray using just enough water to form a liquid.
- Leave furniture in direct sunlight to dry (sunlight also kills mold spores), but don't leave it out too long, or else the furniture may become discolored. For flooring and walls, don't use too much water while cleaning and open up the windows and/or turn on fans to help everything dry quicker.
Alternative Cleaning Agents
For most mold infestations, any combination of vinegar, baking soda, and soap water is enough for thorough removal. However, stubborn infestations may require stronger ingredients for killing black mold, such as borax, hydrogen peroxide, tea tree oil, chlorinated lime, or even bleach. If you use bleach, don't mix it with vinegar or any other ingredients. Mixing bleach with anything other than water will create toxic chlorine fumes. Bleach also damages your wood and paint, so only use it on the tile.
How to Use Borax
Borax is a good natural cleaning choice. Mix a cup of borax with a gallon of hot water and apply it with a rag. Use a clean rag with water to rinse the area afterward because borax will leave a powdery white residue.
3. Sand Away the Mold
If the mold has penetrated deep into the wood, sand it off with some sandpaper, and vacuum up the dust using a HEPA filter vacuum. HEPA filters trap allergens and mold spores to prevent harmful substances from spreading in the air.
4. Pull Moisture From the Air With a Dehumidifier or Desiccant Pack
These are available at the local Home Depot or Lowe's and help pull moisture from the air and trap the airborne particles causing the smell in the first place. Dehumidifiers are not just for absorbing musty smells either. Use one year-round in your basement to control moisture levels. Place desiccant packs in out-of-reach places or corners where moisture might be condensing and replace them frequently.
5. Add a Window Fan
Adding window fans to your basement windows can increase ventilation and reduce the amount of moisture in the basement area while you clean, but it shouldn't be used year-round. Only use it once in a while on cool, dry days to freshen up the basement air.
Warning: DO NOT open basement windows when it is hot, cold, or rainy. This invites moisture and condensation of air on your basement walls, furnaces, and pipes, which leads to mold growth and rot.
What Type of Window Is Best for Basements?
Basement windows should do two things: 1. Keep moisture out. 2. Let plenty of natural light through. Consider getting a double-pane window, which traps heat inside your basement and prevents outside air from coming through. This keeps your basement warm in the winter and is energy efficient.
6. Use Activated Charcoal
Activated charcoal absorbs moisture as well as any odd odors in the air. It usually takes about a week for the charcoal to absorb everything if using this method alone. I recommend using activated charcoal and not charcoal briquettes because it doesn't work as well. If you do opt for charcoal briquettes, DON'T use the kind that has been presoaked in lighter fluid.
7. Place Bowls of Coffee Grounds Around the Basement
Like baking soda and charcoal, coffee grounds absorb foul odors. You can use used coffee grounds, but allow them to dry first. Place in small bowls in every corner of the basement to absorb any stinky smells. The basement might smell like coffee afterward, but that smell will dissipate. If you don't want the basement to smell like coffee, just use activated charcoal or baking soda instead.
How to Prevent Musty Smells
Get Rid of Darkness and Stagnant Air
Open a window during dry, cool weather and let the sunshine and fresh air through. Don't open windows in hot, cold, or rainy weather though. The moisture from the air in warm, cold, or wet temperatures will only invite mildew growth. If your basement lacks windows and sunlight, get a dehumidifier to control the moisture level.
Pipes can be covered in insulation to keep them from getting cold and developing condensate. This will prevent water from condensing and dripping off from them, which creates a mildew oasis.
Repair Leaks and Cracks
Leaky pipes and wall cracks should be repaired ASAP. You may need to call in a professional plumber or contractor depending on the severity of the issue.
Prevent Groundwater Flooding
Problems with outdoor water pooling against the foundation of the home or groundwater flooding should be handled immediately. This not only controls mold and mildew, but also ensures that your home's foundation isn't compromised. Reconsider installing a perimeter drainage system or sump pump to prevent ground or surface water from getting into your basement and damaging your foundation.
Remove Potted Plants
If your basement does not get sufficient sunlight and fresh air, growing potted plants will only contribute to the excess moisture, which leads to mold and mildew growth as well as foul odors caused by plant decay. Plus, houseplants can develop fungus, and before you know it, you'll have to deal with thousands of annoying fungus gnats.
Install Plastic Vapor Barriers
Doing this will seriously save you thousands of dollars and energy and time spent cleaning up mold and dehumidifying. A plastic vapor barrier prevents air from seeping through your ceilings, walls, and floors, basically damp-proofing the entire basement area.
Clean Out Air Ducts
If you happen to have air conditioning ducts in your basement, mold may have grown on in the ductwork of the crawl space. It might even be possible that a dead animal, such as a rat, is rotting in the vent, so you'll need to properly clean out the air ducts to get rid of the musty smell.
Causes of Damp Basements and Musty Smells
The basement is, by definition, underground. This makes the ambient temperature in a basement much cooler than that of the rest of the house. Cooler air is unable to hold as much moisture as the warmer air in the upper levels of the home. When the air from upstairs comes in contact with the air from downstairs, the moisture in the air condenses on the cool basement walls (and any uninsulated cold water pipes that are running through the area). These cold, moist surfaces are the perfect breeding ground for mold. The darker the area, the better it is for mold growth.
Humidity From Outside Air
Outside moisture leaking into the basement can also provide a mold growth environment. When humid, hot summer air enters the basement and cools down, it creates condensation on the walls, pipes, and inside your fiberglass insulation. Try to avoid opening the window when the weather is too hot. This also applies when the weather is rainy and when the air is too cold. Bringing in cold air forces your water heaters and furnaces to work overtime to create heat, and the cold air meeting the hot surfaces of these water and heating pipes will also create condensation.
Dried-Out Water Trap
If you have a sink, laundry tub, toilet, or some sort of drainage system in your basement that never gets used, then you have a dry water trap problem. Any unused water pipes will leak swear gas smells out of the vents and drains. Fortunately, getting rid of the sewer gas smell is easy.
Leaky Pipes and Wall Cracks
That earthy mildew smell might be coming from a broken seal on a basement window or a crack in the foundation wall.
Other things like clogged rain gutters, french drains, or sewer backups can also bring water in contact with the basement walls where water can pool and be absorbed by concrete walls. Leaky pipes are another potential cause of moisture in the basement.
The other major cause of mold and mildew in the basement is the laundry—the dryer in particular. Even though the dryer vent will take much of the heat and moisture from the clothes outside, some of that moisture may condense on the walls and pipes. Properly sealing the dryer vent with duct tape can help.
How to Remove Musty Odor From a Finished Basement
A properly finished basement should never smell musty. If it does, there is either a problem behind your finished walls or in your heating and cooling system.
Locate the Source of Moisture
Locating the source of the moisture in your basement is paramount. If you cannot locate it with a thorough inspection, call in a local energy auditor, HVAC tech, or plumbing professional to find the source for you. If you can find the mold or mildew, get rid of it immediately, using the methods listed above.
Remove the Source of Odor
Removing musty smells from a finished basement could mean placing filters in the ductwork, leaving desiccant packs in out-of-the-way corners, or even odor-absorbing cat litter trays beneath end tables. The key is to keep the moisture down in the basement area. This is usually hardest in the spring and fall when the heating and cooling system isn't circulating air through the home. Consider turning the air handler on your thermostat to "fan" for several hours a day. This will run air through your filtration system and also help keep the humidity down in the basement.
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
© 2014 Everyday Green
Will these tips work on a wood basement? on June 09, 2019:
Will these tips work on a wood basement.
John Dove on May 24, 2019:
Thanks for a comprehensive hub. This is one that I will bookmark and return to for future reference
Travel Chef from Manila on September 21, 2018:
Thanks for sharing this. Mold and mildew can totally cause a problem for homeowners. So it is really important that they learn how to maximize the use of items already available at home.
Janis071954 on March 31, 2018:
THANK YOU JAYE I HAD A SHOWER TRAP AWFUL SMELL.I RAN TO YOUR WEB SITE AND YOU ADVICE SAVED THE DAY.ITS GONE.I LIVE IN A HOME THAT WAS BUILT IN 1930 IN UPSTATE NY.
MARGARET THOMPSON on November 15, 2017:
I have stored my Christmas tree in the basement. I just brought it up and it smells musty, mouldy. I s there a spray I could use to spray the tree. Thank You