How to Get Rid of Mold on Walls (Drywall, Paint and Wallpaper)

Quick answer: To get rid of mold on walls, first fix the moisture that caused it, then scrub small areas on painted walls with detergent and water, wipe clean and dry the wall within 24 to 48 hours. If the mold has soaked into unpainted drywall, the drywall is soft or stained through, or the patch is larger than about 10 square feet, cut out and replace the drywall or call a pro. Finish with a mold-resistant primer and keep humidity below 50%.

Knowing how to get rid of mold on walls starts with one question: is the mold sitting on top of the paint, or growing into the wall itself? Surface mold on a painted wall is a weekend job. Mold that has worked into drywall paper or behind wallpaper usually means replacing material.

This guide walks through both, based on EPA and CDC guidance, plus the steps that keep the spots from coming back next winter.

What causes mold on walls?

Mold needs moisture, and walls get wet in a few predictable ways:

• Condensation on cold exterior walls. Warm, humid indoor air hits a cold wall and leaves water behind, especially in corners, behind furniture and in closets. It’s the same process that fogs windows, explained in our guide on how to stop condensation on windows.
• High indoor humidity. Cooking, showers, drying laundry indoors and poor ventilation keep air above 60% humidity for long stretches.
• Leaks. Plumbing inside the wall, a roof or window leak, or water wicking up from a damp basement floor.
• Bathrooms and kitchens. Steam without a working exhaust fan.
• Past flooding. Drywall that got wet and didn’t dry within 24 to 48 hours.

Is it mold or just dirt?

Mold usually looks like fuzzy or blotchy spots in clusters, often black, green or gray, and it tends to come with a musty smell. Dirt and soot marks are more even and often appear above heaters or in high-traffic spots. A common check is to dab a spot with a little diluted household bleach: mold tends to lighten within a minute or two, while dirt doesn’t change much.

Check your wall type first

Wall surface	What usually works	When to replace
Painted drywall (semi-gloss or satin)	Detergent and water, then dry and prime	If mold returns through the paint or drywall is soft
Flat-painted or unpainted drywall	Light surface cleaning only	Usually, if growth has soaked into the paper face
Wallpaper	Clean the surface, then check behind it	Remove wallpaper if mold is underneath; replace drywall if stained through
Plaster	Detergent and water; plaster is harder than drywall	If plaster crumbles or stays damp
Concrete or block (basements)	Scrub with detergent and a stiff brush	Rarely; fix the water source instead

The EPA’s guidance is clear on the key point: porous materials like drywall and ceiling tiles that have mold growing in them may need to be thrown away, because mold can grow into the empty spaces and crevices where cleaning can’t reach.

How to get rid of mold on walls: step by step

These steps are for small areas, up to about 10 square feet (roughly a 3 x 3 ft patch), which the EPA considers a reasonable DIY job.

1. Find and fix the moisture. Check for leaks, feel the wall for dampness, and measure room humidity. Cleaning without fixing the cause means the mold comes back.
2. Protect yourself. Wear an N95 respirator, long rubber or nitrile gloves and goggles without vent holes, as the EPA recommends. Keep kids, pets and anyone with asthma or allergies out of the room.
3. Set up the room. Move furniture away, lay a drop cloth, and open a window with a fan blowing out. Close the door and turn off central heating or AC for that room so spores don’t travel through ducts.
4. Lightly mist the area. A light spray of water keeps spores from going airborne when you start wiping. Don’t soak the wall.
5. Scrub with detergent and water. Mix a little dish detergent in warm water. Use a sponge or soft brush, squeezed out so it’s damp, not dripping, and work from the outside edge of the patch inward. Change the water often.
6. Wipe and dry. Wipe with a clean damp cloth, then dry the wall completely with fans, open windows or a dehumidifier. The EPA says to dry materials within 24 to 48 hours to prevent regrowth.
7. Check the drywall. Press on the area. If it’s soft, crumbly or stained through the paper after cleaning, it has to come out. Cut the damaged section out with a utility knife or drywall saw, well past the visible edge, bag it in heavy plastic inside the room and replace it.
8. Clean up. Vacuum the floor and nearby surfaces with a HEPA vacuum, bag cleaning rags and sponges, and wash your clothes.
9. Prime and paint. Once the wall has been dry for a few days, apply a stain-blocking, mold-resistant primer, then a mold-resistant paint, especially in bathrooms. Never paint over live mold: it keeps growing under the new coat.

If you use bleach for stains, dilute it (no more than 1 cup per gallon of water), ventilate the room, wear gloves and eye protection, and never mix bleach with ammonia, vinegar or other acids, which releases toxic gas. The EPA notes that bleach isn’t usually needed for mold cleanup; removing the growth and drying the wall is what matters. Keep kids and pets away until surfaces are dry, and follow the label of any cleaner you use.

Mold on wallpaper

Spots on the surface of vinyl wallpaper can be wiped with detergent. But wallpaper, especially vinyl, traps moisture against the drywall, and mold often grows on the back side. If spots keep appearing or the paper is bubbling, peel a corner to check. If there’s mold underneath, remove the wallpaper in that area and treat the wall beneath.

Mold behind furniture and in corners

Dressers, beds and couches pushed tight against an exterior wall block warm air, so the wall behind them stays cold and damp. Clean the mold, then leave 2 to 4 inches of space between furniture and exterior walls so air can circulate. Corners where two exterior walls meet are the coldest spots in a room and often the first to show mold.

Mold on bathroom walls

Bathroom walls get mold from steam, not leaks, in most cases. Clean them the same way, then fix ventilation. Our guides on black mold in the shower and mold on the bathroom ceiling cover the details.

The equipment that helps

The fix for wall mold is dry walls. These tools help you measure humidity, dry the room and clean up airborne spores. For more options, see our best basement dehumidifier guide.

An air purifier is a helper, not a fix. For how to size one, see our best air purifier for mold guide.

How to keep mold off your walls

• Keep indoor humidity at 30% to 50%. That’s the EPA’s recommended range. In winter, aim for the lower end to stop condensation on cold walls. See our guide on how to reduce humidity in your house.
• Ventilate kitchens and bathrooms. Run exhaust fans while cooking and showering and for about 20 minutes after.
• Keep air moving. Leave a gap behind furniture on exterior walls, open closet doors now and then, and don’t block heating vents.
• Keep rooms evenly warm. Very cold rooms next to heated rooms are prone to condensation. Keep them heated at least a little in winter.
• Dry laundry outside or in a vented dryer. A load of wet clothes releases a lot of water into the air.
• Fix leaks fast. Dry any wet drywall within 24 to 48 hours.
• Improve insulation. Mold that returns on the same exterior wall every winter often points to missing or settled insulation in that wall.

When to call a professional

Call a mold remediation professional if the mold covers more than about 10 square feet (the EPA’s guideline), if it came from flooding, sewage or contaminated water, if it keeps coming back after cleaning, if you smell mold but can’t find it (it may be inside the wall), if it’s in your HVAC system or ducts, or if anyone in the home has health symptoms or a weakened immune system. For hidden leaks, a plumber or contractor with a moisture meter can find the source.

Frequently asked questions

Can I just paint over mold on walls?

No. Paint doesn’t kill mold, and mold keeps growing underneath, often peeling the paint and showing through again within months. Clean the mold off, fix the moisture source, let the wall dry completely, then use a stain-blocking primer and mold-resistant paint. If the drywall is damaged or soft, replace it before painting.

Does vinegar kill mold on walls?

Vinegar can kill some surface molds, but it doesn’t remove stains well and it won’t reach mold that has grown into drywall. The EPA recommends detergent and water for cleaning hard surfaces. On painted walls, detergent, a damp sponge and thorough drying do most of the work. Never mix vinegar with bleach.

When do I need to replace moldy drywall?

Replace it if the mold has grown into unpainted drywall, if the drywall is soft or crumbly, if stains come through the paper face after cleaning, or if the drywall got wet from flooding and stayed wet. The EPA notes that porous materials with mold growth may need to be thrown away. Over about 10 square feet, hire a pro.

Why does mold keep coming back on my bedroom wall?

Usually because of condensation. Exterior walls, corners and spots behind furniture stay colder than the room, and humid air leaves moisture on them, especially in winter. Lower indoor humidity, pull furniture a few inches off the wall, keep the room heated and check the insulation. A hidden leak is the other common cause.

Is mold on walls dangerous?

Small patches aren’t usually an emergency for healthy adults, but mold can cause allergy symptoms, irritation and asthma flare-ups in sensitive people, according to the CDC. Babies, older adults and people with weakened immune systems are more at risk. Clean small patches promptly, and talk to a doctor if anyone has symptoms.

How long does it take to get rid of mold on walls?

Cleaning a small patch on a painted wall takes about an hour, plus a day or two of drying before you prime and paint. Replacing a section of drywall takes a few days with mud and paint drying time. Fixing the moisture source, like a leak or poor ventilation, can take longer but matters most.

Mold elsewhere too? Our complete guide on how to get rid of mold covers every room of the house.