How to Remove Mold from Attic Plywood?

Home»Blog»How to Remove Mold from Attic Plywood?

Some people think that some harmless black mold in the attic is no big deal and that it’s just a part of a home’s aging process. However, if your house has mold in the attic, it can pose health hazards to you and your family, destroy your belongings and wooden structural components, and negatively impact the value of your home. Many homeowners want to know how to remove mold in an attic to prevent these issues from worsening.

Hiring a professional contractor who knows how to get rid of mold in an attic is the best way to ensure a thorough and complete job. However, if you spot the issue early, you can take steps to rid your attic of mold before the problem gets out of hand. Read on to learn about the importance of mold removal in attic spaces.

What is Mold?

Mold is a fungus that grows and spreads on damp or decaying organic material. The dusty look associated with mold is due to the formation of the spores it generates as it grows. The spores can manifest themselves in several colors, such as

  • Black
  • White
  • Orange
  • Brown
  • Purple
  • Green

What Are the Causes of Mold in the Attic?

The simple fact is mold will grow if there is moisture in your attic. Mold needs three things to thrive: moisture, oxygen, and organic material, such as plywood. Attics are perfect breeding grounds for mold because they get hot and humid. In Washington, the damp climate allows mold to grow on plywood year-round, while in Southern California, wet winters can accelerate mold growth.

Three situations typically cause black or white mold in an attic:

  • Blocked Ventilation: If the vents that allow air to circulate in the attic become blocked by insulation or other materials, the moisture in the air cannot escape and will condense on the wood sheathing.
  • Roof Leaks: Rain or snow that leaks into the attic will make the wooden structural components wet and breed mold.
  • Improper Venting for Bathrooms and Dryers: If these vents lead into the attic, as opposed to the home’s exterior, they force hot, moist air into the attic whenever they’re in use.

Signs of Attic Mold Problem

If your attic has proper ventilation, it will feel breezy and airy. Attics with poor ventilation will be stuffy and hot. If you think your attic has inadequate ventilation, look for these signs of mold in your attic.

  • A lingering mildew smell
  • Black spots on wood or other discoloration
  • Wet insulation
  • Frost on the roof sheathing during cold seasons

Methods to Remove Mold From Attic Plywood

9 300x200

The first step for mold removal in an attic is eliminating the moisture. Wiping up moldy areas with a rag and detergent can help, but the mold will continue to flourish unless you stop the moisture at the source. Also, be careful not to spread mold spores around your attic by using the same rag to wipe multiple areas.

Safety Precautions

Before starting mold removal, homeowners should take several safety precautions:

  1. Wear Protective Gear: Use disposable clothing, gloves, and a face mask to avoid inhaling mold spores.
  2. Isolate the Area: Seal off the attic to prevent spores from spreading to other parts of the house.
  3. Ventilate the Attic: Open windows and use fans to circulate air and reduce moisture.

Wear clothing you can immediately dispose of and a face mask when cleaning away mold so you don’t inhale the spores, which can make you feel sick. If your mold problem is minimal and you’ve rid the attic of moisture, you can use the following method to kill the mold spores:

Cleaning Solutions

Using Bleach

Bleach can be effective for surface mold removal:

  • Preparation: Mix one cup of bleach with one gallon of water.
  • Application: Spray the solution on the moldy area and let it sit for 15 minutes.
  • Scrubbing: Use a brush to scrub the mold away.
  • Rinsing: Wipe the area with a clean, damp cloth.

Note: Bleach is not effective for porous materials like wood, as it cannot penetrate to kill the roots of the mold.

  • Vinegar: Mix equal parts distilled white vinegar and water in a spray bottle. Spray the solution on the mold and scrub with a brush. Vinegar can penetrate porous materials like wood.
  • Baking Soda: Mix one tablespoon of baking soda with water in a spray bottle. Spray the solution on the mold and scrub with a brush. Baking soda helps deodorize and is gentle on surfaces.

Cost to Remove Mold From Attic Plywood

If you have an extensive mold problem in your attic, you won’t be able to remove it on your own. You’ll have to call a professional who knows how to find all the moisture sources and hiding places for the mold.

The average cost of mold removal in an attic ranges between $1,000 and $4,900, depending on the severity of the problem and the type of repairs required to eliminate the moisture. However, your exact costs will vary.

Keep in mind that hiring a professional to remove the mold in your attic makes it significantly less likely to return than doing it yourself. Also, a persistent mold problem can destroy the personal items you store in your attic and cause thousands of dollars in structural damage to your home.

When to Call Professionals

There are times when professional intervention is necessary to ensure effective mold removal and prevention.

Extensive Mold Coverage

Professional mold remediation is recommended to ensure thorough removal if mold covers a large portion of your attic (more than 10 square feet).

Health Concerns

If you or your family members experience worsening health symptoms (such as asthma, allergies, or respiratory issues) that may be linked to mold exposure, seek professional help.

Individuals with compromised immune systems or preexisting health conditions should avoid mold exposure and rely on professionals for removal.

Structural Damage

If mold has caused significant damage to wooden structures or insulation in the attic, professionals can assess and repair the damage safely.

Professionals have the tools and expertise to find and remove mold in hidden or hard-to-reach areas that may not be visible during a regular inspection.

Hiring a professional ensures that the mold problem is addressed comprehensively, reducing the risk of recurrence and safeguarding your home and health.

Prevention Tips to Avoid Re-infection

Preventing mold from re-infecting your attic requires a combination of good practices to control moisture and ensure proper ventilation.

Improve Ventilation

Proper ventilation is crucial to keeping your attic dry and mold-free. Follow these steps to ensure your attic is well-ventilated:

  • Check Existing Vents: Inspect attic vents, including ridge vents, soffit vents, and gable vents, to ensure they are not blocked by insulation, dust, or debris.
  • Install Additional Vents: If your attic lacks sufficient ventilation, consider adding more vents to improve airflow. This may include installing a combination of intake and exhaust vents.
  • Use Ventilation Fans: In some cases, installing attic fans can help improve air circulation, especially during hot and humid weather.

Install a Dehumidifier

11 300x200

A dehumidifier can help maintain optimal humidity levels, reducing the likelihood of mold growth. Here’s how to choose and use a dehumidifier:

  • Size and Capacity: Select a dehumidifier based on your attic’s square footage. For example, a small attic (up to 500 sq ft) might require a 30-pint dehumidifier, while a larger attic (up to 1,500 sq ft) might need a 70-pint unit.
  • Placement: Position the dehumidifier in a central location in the attic, ensuring there’s adequate space around it for airflow.
  • Maintenance: Regularly empty the water collection tank or provide continuous drainage. Clean the filter periodically to maintain efficiency.

If you don’t regularly clean out the water tank, mold growth can develop. Here are some more steps to keep your humidifier safe:

Wash the Tank Regularly:

  • Frequency: Clean the water tank with soap and water every two weeks or more frequently if the unit is in constant use.
  • Procedure:
    • Unplug the dehumidifier before cleaning.
    • Remove the water tank from the unit.
    • Empty any remaining water in the tank.
    • Wash the tank with warm, soapy water. Use a soft cloth or sponge to scrub the interior.
    • Rinse thoroughly to remove any soap residue.
    • Dry the tank completely with a clean towel before reinserting it into the unit.

Clean the Filter:

  • Frequency: Clean or replace the filter as the manufacturer recommends, typically every month.
  • Procedure:
    • Unplug the dehumidifier.
    • Locate the filter, which is usually accessible from the back or side of the unit.
    • Remove the filter from the unit.
    • Rinse the filter with warm water. If the filter is washable, use mild soap for a more thorough cleaning.
    • Let the filter dry completely before reinserting it into the dehumidifier.
    • If the filter is not washable, replace it with a new one, as the manufacturer recommends.

Dust the Unit and Surrounding Area:

  • Frequency: Dust the exterior of the dehumidifier and the surrounding area at least once a week.
    • Unplug the dehumidifier.
    • Use a soft, dry cloth or a duster to gently wipe down the exterior surfaces of the unit.
    • Pay special attention to the vents and grills to ensure they are free from dust and debris.
    • Dust the area around the dehumidifier to prevent dust from being drawn into the unit.

Fix Leaks

10 300x200

Water leaks can provide a constant source of moisture, fostering mold growth. Take these steps to fix leaks promptly:

  • Inspect the Roof: Regularly check the roof for damaged shingles, flashing, or other issues that could cause leaks.
  • Repair Damage: Patch or replace damaged roofing materials immediately to prevent water from entering the attic.
  • Seal Gaps: Use caulk or sealant to fill gaps around chimneys, skylights, and other roof penetrations.

Proper Venting

12 300x200

Ensure that household vents do not discharge moist air into the attic. Here’s how:

  • Bathroom and Kitchen Vents: Verify that exhaust fans from bathrooms and kitchens vent directly outside, not into the attic or soffit areas.
  • Dryer Vents: Ensure the vent leads outside and is not clogged with lint. Clean it regularly to maintain airflow.
  • Duct Sealing: Inspect and seal any ductwork in the attic to prevent leaks that could introduce moisture into the space.

Post-Removal Inspection

After removing mold, it’s important to ensure that it has been completely eradicated and conditions are not conducive to regrowth.

Visual Inspection

Carefully inspect all attic areas, including hard-to-reach corners and hidden spaces, for any signs of remaining mold.

Look for discoloration on wood, insulation, and other mold-related materials.

Smell Test

Note any lingering musty or mildew smells, indicating remaining mold or moisture.

Moisture Check

Adjust the settings on your in-home humidifier to maintain a comfortable and safe humidity level. This means keeping the relative humidity between 30% and 50% for most homes. The dehumidifier will help reduce the overall humidity load that reaches the attic.

Keep the attic’s relative humidity below 60% to prevent mold growth. You can install a hygrometer in your attic to regularly monitor humidity levels. Keeping an eye on the readings will help you take timely action to control excess moisture.

Set your central air conditioning system to ‘fan’ mode. This setting will keep the fan running even when the system is not actively cooling the house. Continuous air circulation helps reduce humidity levels by promoting better air movement and evaporation.


Schedule regular inspections, especially during high-humidity seasons, to check for signs of mold.

Check and clean the AC filters regularly. Dirty filters can reduce the efficiency of your air conditioning system and impede airflow, which can affect humidity control.

Inspect and maintain attic insulation. Proper insulation can prevent moisture from entering the attic and help maintain a stable temperature, reducing the chances of condensation and high humidity.

Continue using dehumidifiers, ensuring proper ventilation, and fixing leaks promptly.


At Attic Projects, we take every job seriously because we care about our customers and their peace of mind. If your house has mold in the attic, we’ll do a full inspection to determine what is causing the problem and get it straightened out quickly. Call our professionals to get started today!

Leave a Reply

Get A Free attic Inspection

Fill out the form or give us a call to get started!

Customer Reviews

Valentina Mills
Read More
I was extremely satisfied with the work done by the attic cleaning crew. They were punctual, friendly, and incredibly skilled at what they do. They were respectful of my property and took great care to protect my belongings while working. I am grateful for their hard work and dedication, and I can confidently say that I will be relying on their services again in the future. Thank you for a job well done!
Read More
I want to thank Adam, and the installers for being professional at their job. The installers came in and did a great job. They were very courteous and professional, and hard working gentlemen. Had a crack in the drywall, and the project manager got it handled the very next day. Thank you Attic Projects, God bless your business.
Read More
First off, Chase went over and above to explain the process and help me feel comfortable with the investment I was about to make. Then, AJ and Chris took care of business doing a great job. Definitely satisfied with the work they did!

Our Location

Orange County Branch 1607 W Orange Grove Ave, #A Orange,
CA 92868
San Diego Branch 7840 Dunbrook Road San Diego, CA 92126
Seattle / Kent Branch 6839 S 220th St. Kent, WA 98032
Everett Branch 2111 38th St. Everett, WA 98201
Contact Your Local Attic Projects: