If you’re dealing with mold in your basement, you’re not alone. Mold can affect your home’s structure and your family’s health. In this guide, we’ll explore why mold grows in basements, how to remove it, and ways to prevent it from coming back. Whether it’s a small patch or a bigger problem, knowing how to handle mold keeps your home safe and healthy.

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What Causes Mold in Basements?

Basements are prime spots for mold because they tend to be damp and dark. But there are several possible causes of household mold, including:

• Appliance issues: Appliances such as dryers with poor seals can generate condensation, which fosters mold growth.
• Cracks: Rainwater can pour through foundation cracks and generate mold in as little as one to two days.
• Faulty sealing or pump systems: Poor sealing or slow pump systems can cause flooding, creating an environment for mold.
• Flooding: Basements are prone to flooding, which can lead to destructive water damage and mold growth.
• Poor ventilation: Moisture and humidity accumulate without proper ventilation and airflow, which creates an inviting environment for mold.

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How To Get Rid of Mold on Different Materials

The first step to eradicating a mold infestation is understanding how it operates on different surface types. Here’s how to remove mold from different surfaces:

• Wood: White vinegar kills more than 80% of mold species and can be effective in eliminating mold on wood. Mix equal parts water and white vinegar in a spray bottle, then spray generously onto the affected area. Wipe dry after one hour. Sand if necessary and apply a wood sealer to prevent future growth.
• Fabric: Go outside to brush loose mold off of fabrics such as curtains or upholstery. Wash the fabrics with hot water and detergent, adding vinegar or baking soda. Dry the cleaned pieces in the sun.
• Carpet: Cover the affected area with baking soda and let it sit overnight. The next day, scrub visible mold spots with a brush and vinegar. You can vacuum dry mold if your vacuum has a HEPA filter. If the mold has reached the carpet padding, a carpet replacement may be the safest approach.
• HVAC systems: Mold can hide deep in air conditioning ductwork. We recommend seeking professional help to address mold in HVAC systems. 
• Drywall: If mold has compromised the structural integrity of a drywall panel, it’s best to replace it. If the drywall is salvageable, remove mold spores with a vacuum equipped with a HEPA filter. Use a scrub brush soaked in hydrogen peroxide to kill the mold on the drywall. Allow the area to air dry and then prime and paint it using mold-resistant products. 
• Pipes: Mix a solution of half water and half vinegar, pour it down any affected pipes, and allow the mixture to sit for 30 minutes before flushing with water. If mold is on the outside of exposed pipes, scrub the mold with the same solution. Fix leaks to prevent future mold issues.

Check out the video below to see how demo expert Ron Peik and his crew come up with a plan to remove basement mold.

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How To Protect Yourself During Mold Removal

It’s essential to wear personal protective equipment (PPE) to keep yourself safe while removing mold and to prevent mold toxicity. Here’s a list of PPE items you should have: 

• Disposable coveralls
• Disposable gloves
• Head cover
• N95 respirator mask
• Rubber boots
• Safety goggles

Work in a well-ventilated area, take regular breaks, and stay hydrated while removing mold. Dispose of contaminated PPE properly. After you remove the mold, wash your hands and body thoroughly to minimize potential exposure to mold toxins.

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Mold Removal Methods

Knowing how to properly clean mold on various surfaces is essential, as different materials benefit from different strategies. Use cleaning agents such as bleach carefully to avoid potentially harmful chemical reactions.

Consider employing these common mold-removal methods at the first sign of mold in your basement: 

Bleach

Dilute one cup of bleach in one gallon of water and apply the solution directly to the mold. Let it sit for a few minutes, then scrub the mold away with a brush. Avoid using bleach on porous surfaces such as wood or drywall. Never mix it with ammonia or other household cleaners. 

A gallon of bleach costs around $5. 

*Cost information in this article is based on 2024 data from HomeAdvisor, Angi, and Amazon.

Borax

Dilute one cup of borax, a naturally occurring mineral, in a gallon of water. Apply generously to the mold. Allow the mixture to sit for several minutes before scrubbing the mold away. Rinse the surface to avoid leaving behind a powdery residue. 

Borax costs $6.

Concrobium

Concrobium is a specialized mold control product that you can apply directly to a mold surface. Avoid oversaturating the area and maintain proper ventilation while using the product. Expect to pay between $13 and $60 for Concrobium, depending on the bottle size.

Dehumidifiers

Dehumidifiers work by extracting excess moisture from the air, creating an inhospitable environment for mold growth. Place your dehumidifier in a damp area and regularly empty the water collection container. 

A permanent basement dehumidifier can cost anywhere from $1,300–$1,800. Portable dehumidifiers require more maintenance but are less expensive. 

French Drain

A French drain is a trench filled with gravel that redirects water away from your foundation. Installing a French drain around the perimeter of your basement costs anywhere from $5,000 to $18,000.

Hydrogen Peroxide

Hydrogen peroxide is an affordable household staple that can be used on mold. Mix it with water in a 1:1 ratio before applying it to the mold. Let it sit for several minutes before scrubbing. 

A small bottle of hydrogen peroxide costs under $5.

Sump Pumps

Sump pumps automatically pump water out of your basement when the water table rises. Sump pumps cost between $1,200 and $2,500, including materials and labor.

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Should You Hire a Professional for Basement Mold?

Addressing basement mold may require professionals for more powerful or dangerous strains. Here are some scenarios where we recommend calling in the pros:

• Mold types, particularly black mold, covering a large area.
• Mold hidden in ducts.
• Mold causing you health problems or allergic reactions.
• You’re uncertain how to locate or eliminate the type of mold in your basement.

Professional mold remediation isn’t cheap, costing anywhere from $1,125–$3,345. However, a professional mold remediation company can provide thorough removal of the mold, prevent future issues, and save you time and money, making the cost of mold remediation well worth it.

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How To Prevent Future Basement Mold

Preventing mold in your basement is a critical final step in any mold removal project. Here’s a comprehensive approach:

• Enhance ventilation: Be sure that your bathroom or kitchen fans send moist air outside. If exhaust fans aren’t available, open your windows, cover cooking pots, and take shorter, cooler showers.
• Evaluate your basement finishing project: Only finish your basement with insulation and wallboard if it’s very dry. Avoid wall-to-wall carpeting. Instead, choose area rugs that can be cleaned and dried outdoors.
• Invest in a dehumidifier: A dehumidifier can remove excess moisture from damp basements. Make sure the windows are closed during use.
• Keep your home dry: Promptly repair roof and plumbing leaks, and make sure the ground around your house slopes away from the foundation to prevent flooding.

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FAQ About Basement Mold

Will drying out my basement kill mold?

Drying out your basement helps prevent mold from growing, but it won’t kill existing mold. You need to remove the mold and fix moisture problems to keep it from coming back.

Will a dehumidifier kill mold?

Dehumidifiers don’t kill mold, but they help prevent it by reducing humidity levels. Removing the source of mold is the most effective way to deal with growth.

Does bleach kill mold on wood?

Bleach isn’t effective for killing mold on porous surfaces like wood. It’s better suited for hard, nonporous surfaces, such as tubs and tiles.

What kills mold on basement concrete?

Bleach can kill mold on concrete surfaces. Vinegar can also kill mold, but it isn’t recommended for concrete as it can damage the surface.

How do I get rid of moldy basement carpet?

First, address any moisture issues. Then, sprinkle baking soda to absorb excess moisture, vacuum thoroughly, and clean with a carpet cleaning solution. In severe cases, professional cleaning is best.

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