How to Remove Mold From Attic Plywood

If there’s one place in your home that mold loves the most, it’s your attic. Ventilation issues, roof leaks, and poor air sealing raise the chances of a mold infestation even higher.

And what’s even worse is, it’s not child’s play to get rid of mold in the attic. Once it grows on plywood, it’s best to leave it for a professional to deal with. Otherwise, if left untreated, it can significantly impact the quality of air within your house and have a detrimental effect on the health of your household members. For this reason, you can not afford to leave any mold on your attic plywood unattended.

So, without further ado, let’s talk about the symptoms of attic mold and how to get rid of it.

Signs of Attic Mold

Before you hire a professional to remove mold in your attic or have a go at it yourself, here are a few signs that you regularly need to look for that are a giveaway for any mold infestation:

  • Dark staining: Sometimes, moisture can cause your attic plywood to become dark and discolored. But if your plywood has become a victim to mold, the discoloration and dark staining become more pronounced, and that is when you need to hire a professional to remove the mold.
  • Poor air ventilation: Normally, your attic is supposed to be a cool place with great ventilation. But if you start to feel hot and humid whenever you go to your attic, that’s a sign that your attic is a host to mold or is about to become one.
  • Frost accumulation on roof sheathing: Do you notice any frost buildup on your roof sheathing? Well, that’s because the poor ventilation of your attic freezes small water droplets. In time, this frost buildup starts to attract mold, which cozies itself on the plywood.
  • Mildew’s smell: Another obvious symptom, even if you don’t have that sharp of a nose, is the smell of mildew. Whenever you enter your attic and sense a moldy or rusty surface, do not doubt your instincts, and instantly call a professional for mold removal.
  • Wet insulation: Mold loves damp surfaces and moist areas. Hence, if you think your attic’s insulation is getting wet, there’s a high chance that there’s mold in your attic plywood too. Moreover, the moisture and humidity damage the insulation, without which it’s almost impossible to defend against any future mold infestations.

Causes of Attic Mold

9 times out of 10, moisture issues and high water content leads to a mold attack. Hence, if you feel like you have a mold problem at your hand, you will have to deal with the moisture problem first. Following are some of the most common causes of attic mold:

  • Blocked ventilation: In normal circumstances, attics are meant to have a great system of ventilation that allows fresh air from the outside to diffuse in and the air inside the attic to flow out. If your attic has blocked ventilation where the air is either prevented from entering or not allowed to leave the attic, it can cause a series of problems that spell catastrophe for you. The warm, stagnant air can damage the insulation or build up frost, both of which lead to mold.
  • Air leaks: Another reason household owners suffer from mold infestations is air leaks. Sometimes, the wind from the outside finds its way into your attic and gets stuck in the ceiling or floor, which is mostly seen in leaky homes. If that’s the case, you’re inviting mold to your attic because the trapped air is saturated with water particles that are the mold’s best friend. Hence, if you want to keep your attic mold-free, keep an eye out for air leaks.
  • Roof leaks: Remember the wood discoloration that we talked about earlier? That, along with roof valleys, is linked to roof leaks. If there is a fault between the joint or union of two different materials, air and moisture will creep in through that specific point, after which mold will follow. But the good thing is, roof leaks allow mold to grow only in those specific points where there is a leak. So, if you spot a fault in your chimney or vent, don’t delay calling a professional to either prevent or remove mold, depending upon your timing.

How to Remove Mold From Attic Plywood?

Removing mold from your attic plywood is not an easy job, even if you have the right equipment and put in the hours. Hence, we recommend you use the services of a professional to get rid of the mold and make your plywood as good as new. But, if only a few pieces are affected, or if you think you’re up for the challenge, here’s a small guide for removing mold yourself:

For Small Scale Attic removal

 If the mold has only affected a small portion of your attic, the process is fairly simple. But, before you start removing the mold yourself, take these preventive measures:

  1. Wear old or disposable clothes that you can wash or throw away once you’re done with the removal and cleanup.
  2. Wear a special N-95 or P-100 mask along with protective goggles and gloves.
  3. Do not let the room get warm and humid. Keep a fan turned on and open the windows to increase the ventilation.
  4. Do not leave any moldy contaminants in the open. Cover them in a thick, 6mm plastic bag and tape it, while double bag any contaminated debris and throw it instantly in a garbage can.
  5. To deal with the airborne mold particles, use a garden sprayer to moisten the affected areas.

A wet vacuum with an in-built tank for water works best to control the mold residues for small-scale mold removal. Once the surfaces are treated with water, use a sponge or a cloth to wipe the surfaces thoroughly.

Then, use a HEPA vacuum cleaner after the surfaces are dried to rid the plywood of all the mold. While disposing of the contaminants with the rest of the garbage, make sure you seal them tightly in plastic bags and double wrap them if necessary.

If you’re confused about which vacuum to use, take our advice, and go for Vacmaster Pro Hepa Filtration Wet/Dry Vac. This vacuum has 4 distinct filters that work best with the 2-stage ultra-quiet motor. These features make it a great cleaning tool, even for your day-to-day cleaning activities such as getting rid of dust and debris from floors, curtains, and other nooks and crannies.

For Commercial Attic Removal

We can’t stress enough, but removing mold, especially on a large scale, is not supposed to be your next weekend DIY project. Not only is getting your hands on the right tools extremely difficult but there’s always the possibility of you hurting yourself in the process. Even if you manage to get all the equipment and do not injure yourself, you might not cover all the bases.

For this reason, we recommend that you hire the services of a professional mold remover. An additional advantage that comes with a mold remediation company is the satisfaction that they applied the right methods to remove the mold and took adequate measures to make sure you don’t find yourselves in the same spot after a while.

How to Remove Mold Stains in the Attic?

Getting rid of the mold from your attic plywood was one thing. Now, you’ll have to get rid of the mold stains. Otherwise, your attic might not be a pleasant sight to see. There are numerous stain removal products that you can get off the internet.

How to Prevent Attic Mold?

Now that you’ve finally removed the mold and its stains, it’s high time that you also put an end to the problem once and for all. If you don’t deal with the root cause, your attic can and will become a victim of mold yet again. So, let’s talk about the measures you should take to prevent mold from getting to your attic:

  1. Air seal:

The first step to keep your attic safe from future mold infestations is to cover the holes. According to experts, the best way is to fill the bigger holes and deal with the remaining small spots later.

Most professionals cover the large gaps by taking a big plastic bag, preferably a 13-gallon one, and placing a 16-inch long piece of fiberglass insulation in it. Then, remove some of your attic insulation to get to the stud cavity. Once you locate it, fold the plastic bag in half and put it in the cavity.

Now, fill all the stud cavities in the same manner, and cover them with a foil insulation layer. Then, place the original attic insulation that you removed to expose the cavities back again.

Similarly, if there are any leaks in your attic plumbing pipes or wires, fill them with fiberglass insulation. But for insulation, use expanding foam this time. For leaks within electrical junction boxes, even a caulk will suffice.

  1. Add ventilation:

Without proper ventilation, you’re basically inviting mold back to your attic. A passive ventilation system helps recycle the air and prevent it, along with the moisture that it brings, from getting trapped within the attic.

But sometimes, even a passive ventilation system is not enough to get the job done. If you think your attic needs an active ventilation system, try going for a solar attic fan that provides continuous airflow. Solar attic fans work wonders, especially in consistently removing humid air non-stop.


With effective mold removal, you’re not only keeping your home spotless but also ensuring a safer environment for you and your loved ones. Keeping the mold at bay isn’t a skill that’s at the fingertips of any amateur; it requires professional tools, experience, and expertise. When in doubt that there’s mold growing in your attic, call a professional ASAP because health always comes first, and mold puts that at risk. By tackling the problem on time, you’re on your way to a cleaner and greener home.

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