Wondering how to clean mold off wood? It depends on whether it's finished or unfinished.
Time 1 hour or less
ComplexityBeginner
CostVaries
Introduction
Harmful mold can quickly spread if left unchecked. Learn how to clean mold off wood, whether it's finished or unfinished, with this expert-approved process.
When you discover mold in your home, fast and thorough removal is essential to prevent its rapid spread and related health issues. “Proper mold remediation involves removing the active colony, roots, and dead particles,” mold and air quality expert Michael Rubino explains. “This is particularly challenging on porous surfaces like untreated wood, where mold roots and particles embed deep within the surface.”
We spoke with three experts to get their tips on how to clean mold off wood and keep it from coming back.
How to Clean Mold Off Unfinished Wood
Mold removal requires a more methodical approach when it grows on unfinished wood. “Mold grows roots called hyphae, which can penetrate the surface,” Rubino explains. “Like weeds, to fully eliminate mold, you must remove it at the root.
Follow the steps below to clean mold off unfinished wood. (However, if the problem is large or severe or you have concerns about handling things safely, hire a mold remediation professional instead.)
Tools Required
- 3% hydrogen peroxide
- Botanical disinfectant cleaner
- Dehumidifier or fan
- HEPA vacuum
- Latex gloves
- Respirator mask
- Sandpaper
Project step-by-step (6)
Step 1
Prep to remove the mold
“During sanding or other abrasive methods, mold particles can become airborne,” Rubino says. “Set up containment, use protective equipment, and deep clean afterwards to prevent spreading particles throughout your home.”
Mold removal expert Darren Hudema recommends wearing gloves, a P100 mask and goggles or a full-face respirator to minimize exposure to mold spores. “Ensure proper ventilation by opening windows and using fans,” he says. “Before cleaning, dry the wood using a fan or dehumidifier, as mold thrives in moisture, and it’s essential to eliminate the source of dampness.”
Step 2
Remove mold from the top of the unfinished wood surface
First, get rid of the mold sitting on the surface of the unfinished wood. Rubino recommends vacuuming the surface if you have a HEPA vacuum, as the filter helps to contain mold spores. He then advises applying 3% hydrogen peroxide and letting it dry to kill surface mold spores. You can apply this from a spray bottle. Ensure the moldy surface is well covered and let it sit for around 10 minutes.
It’s also possible to clean mold with household vinegar. However, Hudema recommends avoiding using bleach on wood. “It can be too harsh, especially on porous surfaces, and won’t penetrate deeply enough to kill mold at its roots,” he says.
Step 3
Sand the wood surface
Cleaning the mold from the surface isn’t enough, as the mold roots in and feeds off porous, organic wood. “The wood will have to be sanded until there is no more visible mold,” says Jack White, Senior Director of Technical Services at Rainbow Restoration.
After sanding, go over the wood surface with the HEPA vacuum again.
Step 4
Apply a suitable cleaner
As a final step, Rubino recommends spraying the wood surface with a botanical disinfectant cleaner suitable for dealing with water damage, such as Benefect Decon 30. Let it sit for around 30 seconds. “Wipe with a microfiber towel (these are more effective than regular rags),” Rubino says. “Repeat the spray, wipe, and drying process with a clean side of the towel two more times.”
If you don’t have a botanical cleaner, Hudema recommends using a mild dish soap or wood cleaner.
Step 5
Dry the surface
Ensure the surface is completely dry. Excess water can warp or stain the wood and encourage further mold growth.
Step 6
How to Clean Mold Off Finished Wood
Learning how to clean mold off wood sealed properly with mold-resistant paint is simpler than cleaning it off unfinished wood. “These [surfaces] typically do not require sanding because the roots will be unable to grow into the wood,” Rubino says.
Following steps 4 and 5 outlined above should be sufficient. “If the mold grows right back after remediation, the sealing might have been faulty, and the [full] process outlined above should be followed,” Rubino says.
FAQ
How do you prevent mold from growing on unfinished wood?
Minimizing moisture is the best way to prevent damp-loving mold from growing on unfinished wood. Always address underlying issues. Fix leaks in roofs or pipes, ensure your home has adequate ventilation, and regularly clean dust and debris as mold can gather in this. Rubino recommends maintaining indoor humidity levels between 35% and 50%, wiping away any pooling water, and keeping windows and doors closed while the AC is on to prevent condensation from forming on wood-built windowsills and door frames.
Should I add finish to wood after removing mold?
Where possible, it’s better to finish wood after removing mold to create a moisture-resistant barrier. This is especially true in humid, damp spaces within your home. “It also prevents the roots from growing deep within the surface, allowing for a simpler remediation process should growth pop up,” Rubino says.
Why is mold growing on my wood indoor?
Mold grows on wood indoors when there is excess moisture and dampness in your home. Airborne mold spores gather in damp areas and spread. When the wood is unfinished, the mold can penetrate the porous surface and proliferate quickly. It’s important to handle water damage repairs promptly and regularly inspect damp areas prone to mold growth, such as basements, crawl spaces, bathrooms, and kitchens, for mold smells and visible signs.
Can I remove mold from wood without affecting the paint?
Rubino recommends using gentle, botanical cleaners to remove mold from wood as this helps to preserve paint finishes. Avoid harsh chemicals such as bleach.
About the Experts
- Darren Hudema is the Director of Training and Technical Services at PuroClean. The company provides property damage remediation, including mold removal; email interview, Oct. 9, 2024.
- Michael Rubino is a mold and air quality expert, environmental wellness advocate and founder of HomeCleanse; email interview, Oct. 11, 2024.
- Jack White is the Senior Director of Technical Services at Rainbow Restoration, a Neighborly company. Rainbow are rapid response experts in disaster restoration, including mold removal; email interview, Oct. 17, 2024.
