How to Get Rid of a Musty Smell in a Basement or Low Level

That damp, earthy, musty smell in a lower level is more than an annoyance. It is usually a signal that moisture is present, and where there is lingering moisture, there is often mold growing somewhere you cannot see. Masking the odor with air fresheners does not fix anything. To truly get rid of a musty smell, you have to find the moisture, dry things out, and clean up any growth feeding the smell.

A quick note for Southern California homeowners: true basements are less common here than in other parts of the country. Many local homes have crawl spaces, sub-areas, or low-level rooms instead, and those spaces can develop the same musty smell for the same reasons.

Find the Moisture Source

The smell will keep coming back until the moisture behind it is gone, so this is where to start.

Look for common culprits:

• Water seeping in through foundation walls or floors
• Plumbing leaks or condensation on pipes
• Poor drainage around the home that sends water toward the foundation
• High humidity that has nowhere to go in an enclosed space
• Damp crawl-space soil with no vapor barrier

If you can see standing water, staining, or damp materials, you have likely found at least part of the problem. If the smell is strong but the source is not obvious, mold may be growing out of sight, which is a good reason to have the space inspected.

Dry, Ventilate, and Clean

Once you have addressed the water source, the goal is to get the space dry and keep it that way.

Practical steps that help:

• Run a dehumidifier to pull moisture out of the air
• Improve airflow with fans or vents so the space is not stagnant
• Clean small, surface-level mold on non-porous materials while wearing gloves and a mask
• Remove porous items that are damp and cannot be fully dried, like cardboard or soaked fabric
• Keep stored belongings up off the floor and away from walls

Drying is doing more than making the space feel better. It removes the conditions mold needs, which is what actually clears the odor over time. Keep in mind that cleaning surfaces does not remove every spore from the air, and it will not help much if moisture is still coming in.

When the Smell Points to a Bigger Problem

Sometimes a musty smell is telling you something a quick cleanup cannot fix. Consider professional help when:

• The odor is strong or keeps returning after you clean
• You cannot locate the moisture source
• Mold is visible over a large area or on porous materials
• The space feels persistently damp despite a dehumidifier
• You suspect hidden growth inside walls, under flooring, or in a crawl space

These situations usually call for proper moisture detection and containment so the problem is handled at the source instead of just covered up.

If a musty smell in your basement, crawl space, or lower level will not go away, Tri Tech can help. We serve Burbank and Greater Los Angeles with moisture detection, mold cleanup, and drying, and our 24-hour line is always open.