Basement mold and mildew grows in moist conditions.

How to Remove Basement Mold & Mildew Safely

by Merle Huerta

Basement mold and mildew grows in moist, poorly ventilated conditions. Cleaning the mold and mildew is critical; long-term exposure can cause asthma and allergic sensitivity. It also damages property and impacts property value. To clean basement mold and mildew, the Environmental Protection Agency recommends a biocide, or a detergent that kills mold and mildew.

1. Cleaning

1 Locate the moisture source. Repair any plumbing leaks. If the home is built in a flood zone, consider more permanent solutions to prevent water from seeping into the basement.

2. Cleaning

2 Wear protective clothing including non-venting goggles, an N-95 respirator, and rubber gloves.

3. Cleaning

3 Open doors and windows to increase air circulation to the basement.

4. Cleaning

4 Clean mold and mildewed surfaces by scrubbing wood and concrete surfaces with a mild alkaline solution of a half-cup of washing soda to each gallon of water. Other detergents such as trisodium phosphate are sold in hardware stores.

5. Cleaning

5 Rinse wood and concrete surfaces with clean water. Allow to dry completely.

6. Cleaning

6 Eliminate musty odors by scrubbing basement floors with a solution of one cup of bleach to each gallon of water. Rinse well with clear water.

7. Cleaning

7 Run fans in the basement to circulate air. To prevent further mold growth, all surfaces must dry completely.

8. Cleaning

8 Reduce indoor humidity by installing a dehumidifier. Once the basement is dry, run the dehumidifier with windows and doors closed.

9. Cleaning

9 Place a container of silica gel, cat litter, anhydrous calcium sulfate, or other compound that absorbs moisture in the basement.

Items you will need

  • N-95 respirator
  • Rubber gloves
  • Disinfectant detergent
  • Bleach
  • Scrub brush
  • Goggles
  • Fans


  • If mold and mildew covers more than 10 square feet of a basement, the Environmental Protection Agency recommends professional treatment.


  • If a home is built in a flood zone or has a persistent leak, have the water problem evaluated by a professional. Mold and mildew will return if the water problem isn't fixed.
  • Always remove a vacuum cleaner bag outside the home if it has been used to vacuum mold. Do not re-use a bag used to clean basement mold and mildew.

Photo Credits

  • Jupiterimages/ Images