Mildew · Wood
Mildew Stains on Wood — How to Remove Them
Mildew stains on wood appear as dark gray or black patches caused by surface mold, and you can remove them with white vinegar and a scrub brush if you act before the spores penetrate deep into the grain. Unfinished wood needs more aggressive treatment than sealed or painted surfaces, so adjust your pressure and product strength accordingly.
- Time45 min
- DifficultyMedium
- MaterialWood
Watch out
WarningUnfinished or raw wood can absorb vinegar and darken slightly. Test on a hidden spot first.
TipNever use bleach on wood unless it is unfinished and you plan to sand and refinish afterward; bleach can strip finish and discolor stain.
TipIf mildew has penetrated deep into unfinished wood, you may need to sand the surface after cleaning to remove embedded stains.
Do this
Brush away loose mildew
Take the wood piece outdoors if possible, or open windows for ventilation. Use a dry stiff brush to scrub off all loose mildew and surface dust.
Work outdoors to keep mildew spores from spreading indoors.
Apply white vinegar
Pour 1 cup of white vinegar into a spray bottle and spray the stained area until it is thoroughly wet. Let the vinegar sit for 10 minutes to kill the mildew spores.
Scrub with baking soda paste
Mix 2 tbsp of baking soda with just enough water to form a thick paste. Scrub the paste into the stain with a stiff brush, working along the wood grain, for about 2 minutes.
For deep grain stains on unfinished wood, use a toothbrush to work the paste into crevices.
Rinse and wash
Wipe away the paste with a damp cloth. Mix 1 tsp of dish soap with 1 cup of warm water and wash the area to remove any residue.
Dry completely
Wipe the wood dry with a clean cloth and place it in front of a fan or in direct sunlight until completely dry, at least 2 hours. Moisture left behind invites new mildew growth.
Common questions
Can I use hydrogen peroxide instead of vinegar on wood mildew stains?+
Yes, hydrogen peroxide 3 % works well on light-colored unfinished wood and won't darken it like vinegar sometimes does. Spray it on, let it sit for 10 minutes, then scrub with baking soda paste. Rinse and dry thoroughly.
What if the mildew stain won't come out after scrubbing?+
The mildew has likely penetrated below the surface of the wood. On unfinished wood, sand the area lightly with fine-grit sandpaper after cleaning and drying. On finished wood, you may need to strip, sand, and refinish that section.
How do I keep mildew from coming back on wood furniture?+
Keep the wood dry and improve air circulation in damp rooms. Wipe down wood surfaces regularly and avoid placing furniture directly against exterior walls or in basements without dehumidifiers. A thin coat of furniture wax on finished wood also helps repel moisture.
Is this method safe for painted or varnished wood?+
Yes, vinegar and baking soda are gentle enough for most sealed finishes. Test on a hidden spot first and use a softer brush to avoid scratching the finish. If the paint or varnish is already peeling, clean gently to avoid lifting more of the coating.
Same stain, other materials
MildewCarpet
How to Get Mildew Out of Carpet
Mildew on carpet happens when moisture gets trapped in the fibers, and you need to kill the spores and lift the stain before it spreads. White vinegar kills mildew, baking soda absorbs odor, and a stiff brush lifts the residue from deep in the pile. Work quickly—mildew weakens carpet backing and can spread to the pad underneath.
MildewCotton
Mildew Smell on Cotton — How to Get It Out
Mildew smell on cotton clothes comes from mold spores that thrive in damp fabric, and you can eliminate it with white vinegar and baking soda before a hot wash. Cotton is durable enough to handle aggressive odor treatment, so you can use heat and alkaline boosters without worry. The key is to kill the spores and neutralize the musty odor at the same time.
MildewLeather
Mildew on Leather — How to Get It Out
Mildew on leather shows up as fuzzy gray or white patches that smell musty, and you can remove it with isopropyl alcohol and careful wiping. Leather is porous and can't tolerate soaking or harsh scrubbing, so work gently and let it dry completely between steps. Act quickly—mildew eats into the hide and weakens it over time.
MildewUpholstery
Mildew on Upholstery — How to Get It Out
Mildew stains on upholstery come from trapped moisture and mold spores, and you can remove them with white vinegar, baking soda, and careful brushing. The key is to kill the mildew, lift the stain, and dry the cushion or fabric completely so it doesn't return. Always test your cleaning solution on a hidden spot first — upholstery fabrics vary widely in how they tolerate moisture and acid.