How to Identify and Treat Mold in Your Basement

If any place in the house is prone to mold, it’s the basement. Basements collect and hold moisture, and humidity is a factor in mold growth. And because the basement has less natural light and air than other parts of the house, mold won’t go away on its own. Some strains of black mold can pose a health hazard.1 Additionally, mold can quickly decompose organic materials such as wood, causing structural damage. This means identifying and treating basement mold should be a priority as soon as you think you have it.

Mold in the Basement: Identifying and Treating It

Homes with basements often develop mold. Because the basement is close to a groundwater source, water can seep through the concrete floor and continue to seep through the floor sleepers and wall studs. Homes without reliable plumbing systems can accumulate water in the soil, causing the foundation to crack and leading to water leaks.

Identifying and treating basement mold is a multi-step process. You need to find the mold and then test it to make sure what you’re dealing with. If necessary, you will remove structural members to provide access to the mold and perform the mold destruction process. You will then mechanically remove or encapsulate the dead mold spores, whichever works best for your situation. Finally, you will turn your attention to eliminating the problem that caused the mold growth in the first place.

Rules, regulations and licenses
Most communities do not have mold monitoring laws or mandatory mold removal. However, always check with your local permitting agency to see if a mold removal permit is required.2

When to treat mold in the basement
Remove mold in the basement as soon as possible to prevent further growth. If the basement has recently been flooded, remove all water first and wait until the basement is completely dry before attempting to remove the mold.

Security Considerations
Because some strains of mold can be dangerous, wear appropriate personal protective equipment and secure your work area. Personal protective equipment includes at a minimum an N95 HEPA respirator, but ideally a P100 respirator, disposable hooded coveralls, latex or latex gloves, shoe covers, and safety glasses.

Instruct
Materials needed to remove mold in the basement
El/Sanya Kostic
How to Identify Mold in a Basement
Smell the air to detect mold.
One of the first signs that there is mold in your basement is the smell. Mold is variously described as having a musty, dusty, or earthy odor. If you’re familiar with the smell of wet wood or dirty socks, the smell is similar to the smell of mold in the basement.

Check your basement for mold
Identify areas where mold is known to exist.
If you think you smell mold, keep looking for it. Inspect water supply pipes, around drain and sewer lines, anywhere near dryer vents and in laundry rooms, under sinks, on ceilings above finished basements, near bathroom vents, around sump pumps and interior wall cavities.

Check basements for mold
Find the shape visually
Turn on the work lights. Scan it for signs of mold, including small black spots, areas that look like burn marks, or large areas that look dirty.

Detecting mold in the basement
Check for mold with bleach
Add 1 part bleach to 10 parts water in a glass container. Mix well and dip a cotton swab into the mixture. Swipe the swab over the area where you suspect mold. If the surface is dirty, the mixture will not change color. If there is mold, the cleaned area will be lighter in color.

Check for mold with bleach
Explore the area
Carefully insert a screwdriver into areas of drywall or wood that you suspect may have mold. If there is mold, the screwdriver will easily press into the surface, peeling it off. Sometimes the material crumbles.

Feel for mold with a screwdriver.
How to deal with mold in the basement
Prepare your workplace
Ventilate the room with a box fan, directing the air outside. Apply plastic tape around the work area. Turn off your HVAC system or furnace to avoid spreading mold spores throughout the rest of your home.

Prepare the basement floor with plastic sheeting
Dry the work area
Use a wet/dry vacuum to collect water. For other potential moisture conditions, increase the room temperature, turn on the dehumidifier, and run the fan until the room is completely dry.

Dry your work area with a fan
Spray the mold with mold cleaner.
Spray mold removal solution on moldy areas. Use a sponge to wipe the mildew remover off the surface.

Spray to remove mold from basement walls
Clean or pack the mold
Once the mold remover dries, the mold spores are killed, but the mold is still present. You can paint over the mold with a packaged product designed for this purpose, or you can remove the mold with dish soap and hot water.

Clean the mold with a sponge
Adviсe
Surfaces such as bare drywall that may be damaged by excessive use of water should be coated with form sealant for permanent protection rather than cleaned with water.

Prevent mold reoccurrence
A good gutter and downspout system is a step toward reducing basement moisture. The soil layer around the house is facing downwards. A dehumidifier in the basement can reduce the humidity in the air. Seal your dryer vents with metal tape. Check pipes for leaks and repair if necessary.

Take steps to prevent mold from reoccurring
When to call a specialist?
Mold remediation companies can treat mold in the basement, especially if you have large and widespread areas of mold in your home. If you are selling a property, you may be contractually required to have a professional mold remediation company remove the mold rather than do it yourself.