How to Get Rid of a Musty Smell in Your House

What a musty smell means

A musty smell is mold and mildew growing. They need moisture to grow, so somewhere in the house something is staying damp. Sprays and candles can’t fix that. The smell goes when you find the damp, dry it, and clean up the growth.

1. Find where it’s strongest

Close the windows for a few hours so the smell builds up. Then walk through the house slowly. The smell is strongest close to the source. Sniff at floor level, inside sink cabinets, and in closets.

If the whole house smells the same, start at the lowest level. Damp air from a basement or crawl space rises into the rooms above.

2. Check the usual places

• Basement. Damp walls, cardboard boxes on the floor, and old carpet. See our musty basement guide.
• Crawl space. Bare soil and open vents let moisture in. See our crawl space guide.
• Under sinks. A slow drip from a trap or supply line soaks the cabinet floor.
• Around windows. Condensation runs down and rots the sill. See window condensation.
• Closets on outside walls. Cold walls collect damp. See our musty closet guide.
• The air conditioner. A blocked drip pan or drain line grows mold and blows the smell through every vent.
• Behind and under the fridge. Check the drip pan and the water line to the ice maker.
• Bathrooms. Check the caulk, the ceiling above the shower, and under the toilet.
• Laundry. A damp washer or wet clothes left overnight. See washing machine smell and musty towels.

Press on carpets and pads to feel for damp, and look for water stains, peeling paint, and warped wood. If the smell is strong but you can’t see anything, the mold may be inside a wall. Our mold on walls guide explains how to tell. A smell that’s sweet and rotten rather than earthy, and that gets worse over a few days, is more often a dead animal in the wall than mold.

3. Fix the water, then dry everything

Stop the leak or the condensation first. The EPA advises drying wet materials within 24 to 48 hours to keep mold from growing. Use fans, open the windows on a dry day, and run a dehumidifier.

4. Clean or throw out what’s moldy

On hard surfaces, the EPA’s advice is to scrub mold off with detergent and water, then dry the surface completely. Wear gloves and an N-95 mask.

Carpet, padding, ceiling tiles, cardboard, and drywall that have grown mold are hard to clean. The EPA suggests throwing them out. Mold over about 10 square feet, mold after flooding or sewage, or mold in the heating and cooling system is a job for a professional. If you think the ducts or AC are moldy, the EPA says not to run the system until it’s checked.

5. Keep the humidity down

Put a hygrometer in the room where the smell was. The EPA recommends keeping indoor humidity below 60%, ideally 30 to 50%. If it’s higher, run a dehumidifier and fix the moisture sources in our humidity guide.

6. Absorb what’s left

Once nothing is damp, put activated charcoal bags in the rooms that still smell, and wash curtains, bedding, and throws that soaked up the odor. The smell should fade within a week or two. If it comes back, something is still getting wet.