How To Remove Mold From Attic Plywood

How to Remove Mold From Attic Plywood

Attics are arguably the most susceptible to mold because of roof leaks, poor air sealing, and ventilation issues.

However, getting rid of attic mold, especially when it grows on plywood, is a tricky endeavor that most homeowners aren’t equipped to handle. Attic mold can impact indoor air quality and your family’s health, making its removal a top priority.

This article will outline everything you need to know about removing mold from your attic plywood and how to go about it safely and efficiently. Let’s dive in.

Attics and More is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to

Signs of Attic Mold

Signs of Attic Mold

Routinely checking your attic for signs of mold will allow you to identify any problems and avoid panic scenarios. With that said, you’ll still need to know exactly what signs to look for.

Dark Staining

If your attic plywood has dark stains or black discolorations where it’s clear that the problem has moved beyond just moisture, it’s probably mold.

Hot and Stuffy Attic

Ideally, your attic should be cool and well-ventilated. If it’s starting to feel stuffy and hot, that’s a sign of poor ventilation, which frequently causes mold.

Frost Buildup on Roof Sheathing

During the winter, improper ventilation can cause water vapor underneath your roof to freeze. In time, this frost buildup will cause mold.

The Smell of Mildew

If you’ve got a sharp nose, you’ll likely be able to smell musty or moldy surfaces in your attic. Trust your instincts and spot these. Read our detailed post for more information on what mold smells like.

Wet Insulation

If your attic insulation is getting damp, it’s a surefire sign that your attic is far too moist and mold might already exist. It also damages the insulation, increasing the chance of mold in the future.

What Causes Attic Mold?

What Causes Attic Mold

Generally speaking, if you have a mold problem, you most likely have a moisture problem. If your attic plywood is accruing mold, you first need to address the moisture in your attic.

Poor ventilation, air leakages, and roof leaks often cause this issue.

Blocked Ventilation

Attics usually have a passive ventilation system that lets outside air come through soffit vents and then leaves through the can or ridge vents on the top of the roof.

However, if one of these mechanisms becomes blocked, it disrupts the entire system. Warm air stagnates in the attic, then condenses with the cold wood sheathings in the attic. This creates moisture, leading to mold.

Air Leaks

In leaky homes, the air that’s driven by exhaust fans or the wind can blow through ceilings and attic floors. Because this air often contains water vapor, large-scale air leaks can cause condensation, which leads to mold on your attic plywood.

Roof Leaks

Roof leaks will cause mold to form in specific areas of your attic. Check for any wood discoloration and roof valleys. Roof leaks typically occur in chimneys, vents, or elsewhere where dissimilar materials join together.

How to Remove Mold from Attic Plywood

How to Remove Mold from Attic Plywood

Mold growth on attic plywood is a common problem that homeowners need help with.

Mold not only looks unsightly, but it can also pose a health risk to you and your family. If you have mold growing on your attic plywood, removing it as soon as possible is important. Here is a step-by-step guide on how to remove mold from attic plywood.

Materials needed:

  • Protective gear (gloves, mask, goggles, and long-sleeved clothing)
  • Plastic sheeting
  • Bleach or mold remover solution
  • Spray bottle
  • Scrub brush
  • Bucket
  • Water
  • Fan or dehumidifier

Step 1: Prepare the Area

Before removing the mold, it is vital to take some precautions to prevent the spread of mold spores to other areas of your home. Wear protective gear such as gloves, a mask, and goggles. Cover the floor and nearby items with plastic sheeting to protect them from the mold removal solution. You should also ensure that the attic is well-ventilated by opening windows or using a fan.

Step 2: Mix the Mold Removal Solution

Mix a mold removal solution in a spray bottle. You can use a bleach solution (1 part bleach to 10 parts water) or a commercial mold remover solution. Make sure to follow the manufacturer’s instructions on the label for the proper dilution rate.

Our Favorite Mold Removal Product

RMR Mold Killer and Stain Remover

RMR Brands Complete Mold Killer & Stain Remover

We’ve tested dozens of mold removal products. Based on our experience, RMR Brands Complete Mold Killer & Stain Remover is the best product to kill mold and mildew instantly while lifting difficult stains left behind.

Step 3: Spray the Moldy Plywood

Spray the moldy areas of the plywood with the mold removal solution. Make sure to saturate the moldy areas thoroughly. Allow the solution to sit on the mold for at least 15 minutes to kill the mold spores.

Step 4: Scrub the Plywood

Using a scrub brush, scrub the moldy plywood to remove the mold. Scrub in a circular motion, applying firm pressure to remove the mold. Rinse the brush frequently with the mold removal solution to prevent the spreading of the mold to other areas.

Step 5: Rinse the Plywood

After you have removed the mold and rinse the plywood with clean water, use a bucket of water and a clean cloth or sponge to rinse the plywood thoroughly. Make sure to remove all the mold removal solution and any remaining mold spores.

Step 6: Dry the Plywood

Allow the plywood to dry completely. You can use a fan or dehumidifier to speed up the drying process. Make sure the attic is well-ventilated during the drying process.

Step 7: Inspect the Area

After the plywood has dried, inspect the area for any remaining mold. If you see any remaining mold, repeat the process of spraying the area with the mold removal solution and scrubbing the plywood.

Removing mold from attic plywood is relatively simple if you follow the steps above. It is important to take precautions and wear protective gear when removing mold to prevent health risks. Make sure to take steps to prevent mold growth in your attic by fixing any leaks or moisture problems.

How to Prevent Attic Mold

How to Prevent Attic Mold

Preventing attic mold involves controlling moisture levels in your attic. Here are some tips that can help you prevent attic mold:

  1. Improve ventilation: Make sure your attic is well-ventilated to allow moisture to escape. This can be done by installing vents in the roof and soffit and ensuring they are not blocked by insulation or other materials.
  2. Insulate properly: Proper insulation can prevent warm, moist air from reaching cold surfaces, such as the roof deck, where it can condense and lead to mold growth. Ensure your attic is properly insulated and there are no gaps or voids in the insulation.
  3. Use a dehumidifier: If your attic has high humidity levels, consider using a dehumidifier to remove excess moisture from the air.
  4. Seal air leaks: Check for leaks around the attic’s chimneys, vents, and other penetrations. Use caulking or foam sealant to seal these leaks to prevent warm, moist air from entering the attic.
  5. Monitor humidity levels: Keep an eye on the humidity levels in your attic using a hygrometer. The ideal humidity level for an attic is between 30-50%.
  6. Regularly inspect your roof: Inspect your roof for any leaks or damage. Any water infiltration can increase humidity and promote mold growth.

Following these tips can reduce the risk of mold growth in your attic and maintain a healthy home environment.


Removing mold from your attic plywood is a step towards a cleaner, safer, and more energy-efficient home. When dealing with serious mold problems, hire a professional indoor air quality (IAQ) consultant or mold remediation contractors. Please don’t leave it to chance.

And remember, after removal, be sure to get to the source of the problem. Schedule an attic inspection and learn how to make your attic healthier and energy efficient.