Why Does My House Have a Musty Odor?

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Mold growing in the corner behind a piece of furniture.
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If your house has a distinctive and offensive musty odor, understanding what's behind this condition can be critical to home care and maintenance. While the smell is unpleasant, it can mean a more serious problem with your home -- the presence of mold. Learn to recognize the musty smell associated with mold, as well as when you should take action to correct the problem.

Musty Odors

Musty smells are associated with the presence of mold. There are many different types of mold, and they do have slightly different smells; however, smell is often a matter of personal perception. Examples of familiar musty smells might include forgotten damp laundry and wet basements. Mustiness can be described as damp, sour and stale.

Understanding Mold

Mold spores are always present in the air, but when moisture is present, they can grow in your home. Mold and other fungi require dampness to grow, so musty smells are most often associated with basements, crawlspaces, bathrooms and laundry rooms. Visible mold can be vary in color, but powdery white mold, black mold and various shades of gray are among the most familiar in the home. You may not be able to see mold on the surface of your walls and ceilings, even if it is present.

Finding the Source

Follow your nose to find the source of the mold and mustiness in your home. Consider asking a friend or family member with a fresh nose to take a sniff and help you find the source. Pay special attention to anywhere that might have a water leak or another source of moisture, like a clothes dryer that isn't properly vented or a leaky window frame. Assess the situation and repair any leaks.

Small areas of mold can be dealt with using detergent and hot water, but you should wear a respirator. Tiles or drywall may need to be replaced to fully eliminate mold. Areas measuring more than 3 feet by 3 feet should be dealt with by a professional contractor specializing in mold remediation, as recommended by the U.S. Environmental Protection Agency. Mold in the home poses particular risks to the children, the elderly and those with asthma or allergies, and it can worsen symptoms for those with respiratory issues.

Preventing Musty Odors

If you haven't found a leak or visible mold in your home but still have a musty smell, there are things you can do to correct and address this smell. In the summer, run your air conditioner, as it will dehumidify your home. A dehumidifier will also reduce humidity year-round and is an ideal choice if you have a basement that tends to be damp. Exhaust fans installed in bathrooms will reduce moisture in the air in those spaces. If you have addressed the humidity issue, opening windows and encouraging fresh air ventilation will help the residual odor.

Placing small dishes of charcoal in your home may help to absorb moisture and odors; however, these should be kept out of reach of children and pets. Odor-removing products, available where cleaning products are sold, can also help to remove stale, musty smells and replace them with a more appealing scent.


Michelle Powell-Smith

With a master's degree in art history from the University of Missouri-Columbia, Michelle Powell-Smith has been writing professionally for more than a decade. An avid knitter and mother of four, she has written extensively on a wide variety of subjects, including education, test preparation, parenting, crafts and fashion.