How to Safely Clean Mold Off Wood, According to Professionals

It's not uncommon to run across mold on an outdoor deck or antique wood furniture. Mold loves moisture and organic matter, making your favorite wooden chair an easy target. Both an eyesore and a potential health hazard if left untreated, mold should always be cleaned off wood as quickly (and safely) as possible.

We consulted with two specialists who delivered tips and advice on how to clean mold off wood efficiently and keep it from coming back.

Safety Precautions—and When to Call a Pro

Before diving into cleaning, it’s important to understand how to keep yourself safe. Dion Dunbar, senior technician at Masters Remediation Services, warns that cleaning mold can aggravate respiratory conditions due to the release of spores.

Dunbar recommends wearing protective eyewear, an N95 mask, and gloves during the cleaning process. He also suggests opening a window, working in highly ventilated areas, and using a HEPA-filtered air purifier if possible. 

"If it's impossible to tell what kind of mold it is, or someone in the home has health concerns, it's safest to bring in a certified specialist," adds mold and restoration specialist Jason Bruning. "If the mold covers more than a small area (over 10 square feet), keeps coming back, or is in a tricky spot like behind walls or near HVAC systems, call a professional for help," Bruning says.

How to Clean Surface-Level Mold Off Wood

Bruning explains that pros often use probes and moisture meters to determine how far the mold has spread, but you can often tell by look and feel. “If the mold wipes off easily and the wood underneath feels solid and dry, it’s likely just on the surface,” Bruning says. “But if the wood looks discolored, feels soft, or has a musty smell that won’t go away, the mold may have penetrated deeper.”

If you’ve determined the mold on your wood is more surface-level, here’s what you’ll need to tackle the issue, according to Bruning and Dunbar. 

Materials:

• HEPA-filter vacuum
• White vinegar 
• Spray bottle
• Water
• Soft-bristled cleaning brush
• Cleaning cloth 

Instructions:

1. Use a HEPA vacuum on the moldy area to remove loose spores.
   
2. Mix equal parts water and white vinegar into a spray bottle.
   
3. Spray the mixture on the mold, avoiding over-saturating the area. Let the mixture sit for 10-15 minutes.
   
4. Scrub the moldy spot with a soft cleaning brush.
   
5. Wipe the spot clean with a cloth. Allow to dry completely in a well-ventilated area.

How to Clean Deeply Penetrated Mold Off Wood

Tried the above cleaning method and still notice mold? Here are the next steps you’ll need to take. 

Materials:

• Mold-specific cleaner
• Sander tool
• Cleaning cloth
• Borate-based wood treatment 
• Anti-microbial sealants

Instructions:

1. Read all commercial cleanser instructions and perform a spot test first, ensuring that all products can safely be applied to wood.
2. Apply a moderate amount of mold-specific cleaner to the moldy area. Allow to sit for the specified time on the label.
   
3. Wipe the area with a cleaning cloth. Allow to dry completely.
4. After the wood is completely dry, lightly sand the area.
5. Apply a borate-based wood treatment and anti-microbial sealant to protect the wood. 

How to Prevent Future Mold

To keep mold from returning to wood, both of our experts say it is critical to manage moisture in the offending area. This is especially important around walls, beams, and wooden furniture. Mold thrives in places with high humidity, poor airflow, and near water sources like bathrooms and kitchens. Even condensation on cold surfaces can trigger growth.

And don't skip final steps: After deep-cleaning any moldy wood, it’s important to protect the surface with a sealant to keep moisture out.