clock menu more-arrow no yes

How to Prevent Mold in Your Basement

Got mold in your basement? Read this guide to learn how to identify and treat mold.

Getty Images/iStockphoto

When we think of a home’s basement, we often imagine dark, damp places with old holiday decorations and lots of spiders. And what else? Mold.

What is Mold?

Mold (sometimes called mildew), is a type of fungus. It’s made up of small organisms that send out tiny spores to reproduce when they find somewhere wet. These spores can attach themselves to clothing, hair, shoes, or just travel on the wind — and you encounter them throughout your day, mostly without noticing.

What Causes Mold to Grow in Basements?

Mold loves temperatures between 60 and 80 degrees F, a little bit of moisture, some tasty surfaces to feed on, and plenty of room to grow—all of which the average basement supplies readily.

You can have issues with mold after a small leak, say, from a water heater or bathroom, rain coming in a basement window after a big storm, a major flood event, an overwatered plant pot, or even just due to an excess of indoor humidity.

What Does Mold Look Like?

We like mold for making a tasty cheese, but we don’t want it downstairs. To find it, you might have to dive deep and get behind surfaces. Indoor mold doesn’t necessarily look very menacing.

It comes in all colors from white to green to black. You might have heard about “black mold” (a name that sounds pretty terrifying), but in truth that type of mold isn’t the most common one found in homes. Four other types are much more common, according to the Centers for Disease Control (CDC), and they include Cladosporium, Penicillium, Aspergillus, and Alternaria. The type that creates black mold is technically Stachybotrys chartarum (or alternately, Stachybotrys atra).

One thing they all have in common is their favorite types of places to grow, which the CDC notes can include wet cellulose materials, including paper and paper products, cardboard, ceiling tiles, wood, and wood products, as well as dust, paints, insulation materials, drywall, carpet, fabric, and upholstery.

The Health Risks of Mold

Along with being pretty unsightly, certain molds can pose major health risks. Some people are sensitive to mold as an allergen, and it can cause anything from eye and throat irritation to asthma or more serious illnesses in those with compromised immune systems.

In fact, indoor mold issues pose such a widespread problem, that the World Health Organization (WHO) released an extensive report on air quality guidelines concerning mold. In the report, they noted that it doesn’t take a flood event to lead to mold in a building or home, but in fact the majority of mold spores come inside via the regular airflow. These spores, when they find a moist spot to multiply, create issues of health-impacting poor air quality in these spaces where we all spend the majority of our time: inside.

How to Get Rid of Mold

Small amounts of mold can be cleaned up with soap and water or a bleach and water solution (1 C. bleach to 1 gal. water) and a thorough scrubbing to get rid of dead mold spores.

But if you have extensive water damage or mold growth, you should seek professional help in the form of a trained mold remediation specialist. The Environmental Protection Agency (EPA) recommends that you call in a professional if the mold is widespread, or is more than 10 square feet in size.

How to reduce the chances of getting mold in your basement:

  • Look for condensation on windows or walls. Add insulation to avoid condensation forming on cold surfaces when the inside of your home is warmer than the outside.
  • If you have a water leak, clean up the moisture quickly and ventilate the area thoroughly until all is dry. Don’t paint or cover up areas until they are dry.
  • Remove and discard water-damaged ceiling tiles, drywall, insulation, carpet, and furniture after a leak. Have sentimental items that got wet? Get a specialist to clean them for you.
  • To reduce humidity, use an air conditioner or a dehumidifier and empty the collected moisture frequently. Mold doesn’t like humidity below about 60%. Use a simple hydrometer to measure your indoor humidity to keep tabs.
  • Clean your air ventilation systems regularly, and check filters and intake systems in your HVAC system for any mold growth.
  • Add ventilation as a permanent feature to make sure your rooms get enough airflow, including basement bathrooms, laundry rooms, and other spaces where mold might want to stay long-term.