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Why Does Mold Smell Earthy and How to Eliminate It?

Last updated October 31, 2026

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The short answer

What Causes the Earthy Smell

Mold produces chemicals called microbial volatile organic compounds, or MVOCs, as it feeds on organic materials like wood, drywall, and dust. These compounds evaporate into the air, and your nose picks them up as a musty, earthy, or soil-like scent. The smell is often the first clue that mold is growing somewhere hidden.

The intensity of the odor depends on the type of mold, the surface it is growing on, and how long it has been present. A small patch behind a baseboard may smell faint, while a large infestation in a wall cavity can make an entire room smell damp. The earthy smell is not harmful by itself, but it signals that mold spores may be in the air.

Find the Moisture Source First

Mold cannot grow without moisture. Before you can eliminate the smell, you need to find and stop the water source. Check for leaks under sinks, around toilets, near windows, and along the roofline. Look for water stains on ceilings or walls, and feel for damp spots on carpet or drywall.

If the moisture comes from a plumbing leak or a roof issue, you may need a plumber or a roofer to fix it. For larger water problems, such as flooding or a burst pipe, local water damage pros can help with cleanup and drying. Once the moisture stops, the mold will dry out, but it will not die unless you remove it.

  • Check under sinks and around appliance connections
  • Inspect the attic and crawl spaces for roof leaks
  • Look for condensation on cold pipes or windows
  • Feel walls and floors for dampness after rain
  • Use a moisture meter if you have one
  • Check the AC drain line for clogs or overflow

Remove Mold from Surfaces

To get rid of the earthy smell, you must physically remove the mold. For non-porous surfaces like tile or glass, scrub with a detergent and water solution. For porous materials like drywall, wood, or carpet, mold can penetrate deep, so removal is often necessary. Cut out and replace affected drywall or remove water-damaged flooring.

Do not use bleach on porous surfaces because it only bleaches the mold on top and leaves the roots below. Use a product made for mold removal, or a mild detergent solution. Always wear gloves, goggles, and a mask when cleaning mold to avoid breathing in spores. If the mold covers a large area, more than a few square feet, consider calling a mold professional.

After cleaning, dry the area thoroughly. Use fans or a dehumidifier to lower humidity levels. Keep the space ventilated for several days. If the smell lingers, there may be mold hidden behind walls or under flooring that you cannot see. In that case, a professional inspection can locate the problem.

Clean the Air and Fabrics

The earthy smell can cling to curtains, upholstery, clothing, and carpets. Wash washable fabrics with hot water and detergent. For items that cannot be washed, such as large furniture or carpets, you may need to have them professionally cleaned or replaced if the mold has penetrated deep.

Air purifiers with HEPA filters can help remove mold spores from the air, but they do not eliminate the source. Activated charcoal or baking soda can absorb odors temporarily, but they only mask the smell. The only lasting solution is to remove the mold and control moisture.

Keep an eye on indoor humidity levels, especially after rain. A dehumidifier can help in damp areas like bathrooms or utility rooms. In a hot, dry climate, indoor moisture is often manageable with good ventilation.

When to Call the Pros

If the mold covers a large area, if you cannot find the moisture source, or if the smell persists after cleaning, it is time to call local water damage pros. They have the equipment and experience to locate hidden moisture, remove mold safely, and dry out your home. They can also handle water-damaged drywall and flooring.

In some cases, mold can cause health issues like allergies or respiratory problems. If you feel unwell, see a doctor. Your insurance policy may cover mold removal in certain situations, but policies vary, and your insurer decides what is covered. Check your policy to understand what is included.

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Frequently asked questions

Can I just paint over mold to get rid of the smell?

Painting over mold does not eliminate the odor and can make it worse. The mold continues to grow underneath the paint, and the smell will eventually come through. You must remove the mold and fix the moisture problem first, then you can repaint.

How long does the earthy smell last after cleaning?

The smell can last for days or weeks, depending on how much mold there was and how well you cleaned. If you removed the mold and dried the area completely, the smell should fade over time. If it lingers, there may be hidden mold that you missed.

Is the earthy smell dangerous to breathe?

The smell itself is not toxic, but mold spores can trigger allergies or asthma in some people. If you notice symptoms like sneezing, coughing, or eye irritation, limit your exposure and see a doctor. Removing the mold is the right way to protect your health.

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