How to remove mold from the attic

How to remove mold in the attic.

Attic mold is something not to be taken lightly or ignored – regardless of whether or not the species is toxic. The good news is that it is highly unlikely for attic mold to spread to other parts of the home because hot air rises. On the other hand, leave it long enough, and you will end up paying large sums of money to have your roof/attic repaired and cleaned.

So, if you have an attic that you’ve been neglecting for some time, then you might want to investigate. Luckily, we will guide you through the process of how to know if you have an issue with mold in the attic and how to do deal with it.

Topics Covered

  • Is mold in the attic common?
  • Can mold in the attic make you sick?
  • What type of mold grows in attics?
  • How to test for mold in the attic?
  • Causes and prevention
  • How to get rid of mold in the attic

Is mold in the attic common?

Yes, it’s very common. It’s believed that most homes in North America with attics have mold to some extent.

Can mold in the attic make you sick?

It depends on the type of mold and from person to person. Some people may experience headaches, rashes, sinus problems, etc., while others won’t have any symptoms at all.

However, certain species such as Memnoniella Echinata and Stachybotrys Chartarum, produce mycotoxins and aflatoxins, which hold more severe health issues with long term exposure.

Also, as mentioned, hot air rises – so attic mold is unlikely to spread to the lower parts of the house. Therefore, the only way it will affect your health is if you physically go up into the attic area.

What type of mold grows in attics?

Knowing the exact species is impossible without having tests done. On the other hand, it is possible to more or less narrow the type down by its color.

Black mold in the attic

When people come across a black colored mold, most will panic because they will automatically assume that it’s Stachybotrys Chartarum. The truth is that there are many hundreds of mold species that appear black, and most are relatively harmless. It’s not to say that Stachybotrys is uncommon, but you’re most likely to encounter it in flood-damaged homes.

Green mold in the attic

Green mold can be any of hundreds of species. However, the most common types of green attic mold are Penicillium, Cladosporium, and Aspergillus – none of which you want because they produce mycotoxins/aflatoxins.

White mold in the attic

White mold in the attic is just as common as black mold. Although the white varieties can be any number of species, the good news is that it’s usually easier to remove than say, black or green mold.

It’s also important to know that most species start white during it’s beginning stages before turning green, yellow, or black.

How to test for mold in the attic?

Attic mold.

There are two ways of testing – you can do it yourself or get a professional mold remediation company to do it for you.

If you have found mold in the attic and it’s in a small quantity, then you will be able to remove it yourself easily. Doing a test to determine the species may not be necessary, as your primary concern should be to remove it as soon as possible.

On the other hand, if the infestation is large, then it would be best to let the professionals take care of it. The company doing the removal would, in this case, also take care of testing to determine the type/s of mold.

There may be some cases that you strongly suspect mold being present in the attic, but cannot locate it. If this is the case, you can conduct your own airborne test to determine whether or not mold is present.

What causes mold in the attic and how to prevent it?

The most common cause is a combination of insufficient ventilation and too much moisture.


Moisture acts as a food source for mold and helps it spread rapidly. This very moisture is caused by either a water leak or high humidity levels in the attic itself.

If any plumbing pipes are running through the attic, then you may want to inspect them for leaks. Another water source could be from damaged roof tiles that allow rainwater to seep through into the attic on rainy days.

Solution: Fix leaking pipes and damaged roof tiles.

Poor ventilation

The ideal attic should feel reasonably breezy. If yours is hot and stuffy, then you most definitely have a ventilation problem.

Solution: The solution to this problem is to create a continuous airflow through the attic area. This can be easily accomplished by installing an intake and exhaust vent. Read more about this.

How to get rid of mold in the attic

There are a few things that should be taken into account before we get to the step-by-step instructions.

Firstly, how widespread is your attic mold problem? If it’s in relatively small quantities, then taking the DIY approach is perfectly fine. If the infestation is large, on the other hand, then you may want to seriously consider hiring a professional to take care of it.

Secondly, safety is of paramount importance. The attic could be infested with mold spores, and even if it isn’t, it could be once you disturb the mold. That is why you will need some essential safety gear. Using a respirator mask, safety goggles, and gloves is strongly recommended. Also, wear old clothes that you can discard afterward because the spores tend to stick to clothing.

Step 1: Kill the existing mold and remove the spores (Optional)

If you know for sure that there is a very high mold spore count in the attic, either indicated through an airborne test or by allergies flaring up, then you may want to kill and remove them before starting any cleaning work.

This step may not be necessary as it depends on the severity of the infestation and how your body reacts to the spores. Luckily though, it requires minimal effort on your part.

Set off a microbial fogger or mold fogger aerosol can in the attic to kill all mold, its spores, and any other fungi and bacteria that may be lurking in there. This alone will sanitize the attic area and prevent mold from growing and spreading any further.

The spores will be dead, which is a good thing. However, they will still trigger the exact same allergic reactions when inhaled. This is easily solved by capturing them from the air with a HEPA air purifier.

Important: Before setting off the fogger, ensure that all openings in the attic are thoroughly sealed.

Step 2: Get your cleaning solution ready

We always recommend using safe/organic items such as vinegar and baking soda.

To prepare: Mix white distilled white vinegar and water at a 50/50 ratio into a spray bottle – this alone is a great mold killer, but for extra power, add a teaspoon of baking soda and shake it up well.

You can also use 3% hydrogen peroxide or borax if you do not have any vinegar and baking soda available.

Step 3: Remove the mold

Next up, we will be physically removing the mold. Finding and removing all traces of it is important – especially if you opted out of the first step.

Check all wooden surface areas such as floors, rafts, and sheathing. Heavily spray your mold solution onto the problem areas and allow 20 minutes to soak in before scrubbing it off.

Many people also use their attics as a storage area, so check every item you have stored for mold growth as well.

Step 4: Dehumidify (Optional)

As mentioned, the cause of mold growth in the attic is a direct result of improper ventilation and moisture.

Fitting a properly functioning ventilation system is essential for keeping mold at bay, and there is no point in cleaning mold without addressing this problem.

If you fitted a ventilation system before cleaning, then no further steps are necessary. However, if you haven’t done so yet, the mold will eventually come right back. Running a dehumidifier in the attic, for the meantime, is a good idea as it will keep the mold away until you get a ventilation system fitted.

More Information

The bset dehumidifiers suited for attics

How to use white vinegar as an effective mold cleaning-solution

How to use baking soda as an effective mold cleaning-solution