6 Ways to Fix Damaging Basement Moisture

Musty. Dank. Damp. Do these words describe your basement?

If so, you may have an undesirable, and potentially hazardous moisture problem in your home. Moisture in your basement is bad for your health and can, in some cases, be dangerous. Damp conditions could cause mold growth and or attract bugs and vermin, all of which can introduce bacteria and microorganisms into the air. “Moisture transfers from high moisture content to lower moisture content. So, if there is ductwork for air conditioning or heating in the basement and that ductwork is leaky, airborne mold spores or other unhealthy bacteria can be drawn into the ductwork and be carried throughout the entire house,” says Chad Farnum, Owner of Farnum Insulators.

Basement moisture can also compromise wooden structural components of your home like floor joists, rim boards and support columns. Rot in these components can cause serious structural damage to a home!

What’s a homeowner to do? Here are six easy fixes to tackle moisture in a basement:

  1. Seal Ductwork

Sealing heating and air conditioning ductwork will ensure that the heavy moist air, mold, mildew or other bacteria will not be drawn into the ductwork and be distributed throughout the house.

  1. Cover the Dirt Floor in Your Basement

“Moisture problems in homes are very common, but they’re often not properly diagnosed and treated,” says Farnum. “In New England, a lot of houses have dirt floor basements, which can lead to heavy moisture loads in the house.” Dirt floor basements release more moisture than other types. They cause problems because they are able to draw moisture from the ground and release it into the air, causing dampness to hang around even in the wintertime. The best way to fix this is to weatherize the basement by having a heavy-duty vapor barrier installed over the dirt floor. Installers, such as the experts at Farnum Insulators, will then seal the vapor barrier to the exterior foundation walls using closed cell spray foam.

  1. Do Not Open Basement Windows

If your home isn’t properly weatherized, keeping your basement windows open to catch the warm summer breeze might actually add more moisture into your basement. “When you open your basement windows during the warm summer months, it can result in the warm moist air that's being drawn in condensing on the cooler surfaces within the home” says Farnum.

  1. Don’t Use a Dehumidifier in a Basement or Crawl Space with a Dirt Floor

Contrary to popular belief, using a dehumidifier to reduce moisture in your basement or crawl space with a dirt floor won’t work. The dehumidifier will just draw moisture out of the ground, which is then replaced with more moisture from the ground. This is a huge waste of energy and does not solve the moisture problem.

  1. Make Sure Dryer Vents are Vented to the Outside

“We find that another common thing that leads to excessive moisture in a basement is when clothes dryers are vented into the space,” says Farnum. Heavy moist air produced by a dryer in a basement is a recipe for big moisture problems!

  1. Stop Storing Firewood in the Basement

Fresh firewood is full of moisture and storing it in your basement can cause issues, according to Farnum. “The common mistake that people make is leaving firewood to dry in the basement. The moisture from the wood is drawn out, creating an environment for mold and mildew growth.”


Farnum Insulators has been making New Englanders more comfortable in their homes for more than a decade. Check out their easy financing options at Farnuminsulators.com