How to Get Rid of Mold Smell: Find the Source, Then Fix It
You can't air-freshen away mold smell. Here's how to track down where it's coming from, fix it, and clear the leftover odor.
A mold smell means mold is growing somewhere, so the smell won’t go away until you find the source, fix the moisture, and clean or remove the growth. Then air out the space and bring humidity down to 30% to 50%. Baking soda and activated charcoal can absorb leftover odor. Sprays and candles only cover it up. Call a professional if the source is hidden in walls or ductwork, the growth covers more than about 10 square feet, or the smell followed a flood.
Step 1: Track down the source
Musty smells are strongest close to the growth. Walk through the house slowly and sniff. Check closets, under sinks and low, cool spots. Common culprits:
| Where to look | What to check |
|---|---|
| Under sinks | Drips from traps and supply lines, swollen cabinet floors |
| Bathrooms | Caulk, grout, behind the toilet, under the bath mat, the exhaust fan |
| Laundry | Front-loader door seal, detergent drawer, damp clothes left in the drum |
| Basement | Walls and floor corners, stored cardboard boxes, carpet, the sump area |
| Closets on exterior walls | Back walls, shoes, stored clothes, luggage |
| Windows | Sills and tracks where condensation collects |
| Kitchen | Under the fridge (drip pan), dishwasher seal and filter, behind appliances |
| Heating and cooling | Smell is stronger when the system runs, or comes from vents |
Look for water stains, peeling paint, warped flooring or baseboards, and condensation. A cheap hygrometer will tell you if a room’s humidity is high.
Step 2: Fix the moisture
- Repair leaks and drips.
- Dry wet materials within 24 to 48 hours, as the EPA advises. Use fans and a dehumidifier.
- Keep humidity below 60%, ideally 30% to 50%. See does a dehumidifier help with mold.
- Run bathroom and kitchen exhaust fans, and make sure dryers vent outdoors.
Step 3: Clean or remove the growth
What you need
- Dish detergent and warm water
- Scrub brush, sponges and disposable rags
- Gloves, goggles without vent holes and an N95 respirator
- Trash bags
Steps
- Open windows and keep children and pets out of the area.
- Scrub hard surfaces with detergent and water, then dry them completely.
- Bag and discard moldy porous items that can’t be cleaned, such as cardboard boxes, ceiling tiles, and carpet padding that got wet. The EPA notes that porous materials may need to be thrown away.
- Wash fabrics on the warmest setting the care label allows. See how to get the smell out of towels.
- Recheck in a few days. If the smell is back, there’s still moisture or hidden growth.
If you use a bleach solution on hard, non-porous surfaces, the CDC says no more than 1 cup of household bleach per gallon of water. Follow the label, ventilate well and wear gloves. Never mix bleach with ammonia, vinegar or other cleaners. Use one product at a time and rinse with water between them.
If someone swallows, inhales or gets a cleaning product in the eyes, call Poison Control at 1-800-222-1222 (US) or emergency services.
Step 4: Clear the leftover smell
Once the source is gone, the remaining odor usually fades. You can speed it up:
- Air out the space with open windows and fans on dry days.
- Baking soda: sprinkle on dry carpets and upholstery, leave for several hours, then vacuum. Test on a hidden spot first. Open boxes work in closets and cabinets.
- Activated charcoal: bags or bowls in closets, cabinets and basements can absorb odors. Some products can be refreshed in the sun; check the package.
- Wash soft items like curtains, cushion covers and throw rugs.
- Clean the HVAC filter and replace it if it’s due.
Masking vs. fixing
Air fresheners, scented candles and odor sprays hide the smell but leave the mold growing. Ozone generators are sometimes sold for odors. The EPA says they are not reliably effective against odors or mold and can harm your lungs, so skip them in occupied homes.
When the smell comes from the HVAC system
If the musty smell gets stronger when the heat or air conditioning runs, mold may be in the ducts, coils or drain pan. The EPA says not to run your HVAC system if you know or suspect it’s contaminated with mold. Turn it off and call an HVAC professional who has experience with mold.
When to call a professional
- You can smell it but can’t find it. It may be inside walls, under floors or above ceilings.
- The growth covers more than about 10 square feet.
- The smell started after a flood, sewage backup or long-running leak.
- It’s in the heating or cooling system.
- Someone in the home has asthma, allergies or a weakened immune system. Check with a doctor before cleanup.
The EPA’s Mold Cleanup in Your Home page covers who should do the work. For a whole-house musty smell, see how to get rid of a musty smell in the house, and for walls, how to get rid of mold on walls.
Bottom line
A mold smell is a clue, not the problem itself. Find the damp spot, fix the moisture, clean or remove the growth, and bring humidity down. Then air out the space and use baking soda or charcoal for what’s left. Fresheners and ozone machines only hide the warning sign.
FAQ
Does a musty smell always mean mold?
Usually it means mold or mildew is growing somewhere damp, though a dirty drain or washer can smell similar. Either way, look for moisture.
How long does a mold smell take to go away?
Once the source is removed and the area is dry, the smell often fades within days with good airflow. If it lingers, something is still damp.
Does vinegar remove mold smell?
Diluted white vinegar can help clean and deodorize some hard surfaces. Never use it on natural stone, and never with bleach.
Should I test for mold if I only smell it?
A professional inspection can help find hidden growth. Store-bought test kits usually can’t locate the source.
