How to Deodorize a Basement

Kimberly Johnson

Because basements are underground, they have a variety of unpleasant odors including earthy smells of dirt and musty mildew. These odors persist for long periods because basements often have no windows or doors and air circulation is limited.

Basements often have a musty smell from mold.

If you plan to spend time in the basement or store items such as food or clothing, you must remove these odors. Use items that absorb smells from the air instead of masking them.


You can also cut a large onion in half and place it on a plate. Set the onion in the basement overnight to absorb airborne odors. At first there will be strong onion smell, but it will dissipate along with the other odors.


Regular charcoal used for cooking does not absorb odor as well as activated charcoal.

  1. Open any windows or doors in the basement to allow for air circulation, which will remove unpleasant odors and help dry out moisture. Leave them open in the day and close at night before going to bed. Repeat the process until the unpleasant odors are gone and to prevent them from redeveloping.

  2. Purchase a deodorizing spray with antifungal properties and spray it on all walls and other hard surfaces to kill any mold spores or other undesirable odors clinging to them.

  3. Sprinkle chlorinated lime powder over the floor of the basement until you can no longer see the floor. Allow it to sit for five to 10 minutes, then sweep it up using a dustpan. The chlorinated lime removes any odor-causing microbes on the floor.

  4. Fill three to four large plastic storage containers with activated charcoal, which is available in home improvement and pet stores. Pour a 3- to 4-inch layer of charcoal into each storage container and leave the lids off.

  5. Set the storage containers in the basement at equally spaced distances. Leave them there until the charcoal absorbs all of the odor and the interior air smells pleasant again.