What You Need to Know About Mold in the Attic

Updated by Lisa A on January 21, 2019 in

Mold Remediation, Mold Testing, Mold Inspections

Along with basements, attics are often the site of mold infestations, as they are prone to water intrusion from leaky roofs, air leakage from bypasses, and sometimes disconnected vents (disconnected dryer vents are frequent culprits). Prompt remediation will help safeguard your family's health and your home's value.

 Attic mold

Identifying the source of attic mold

Since every mold problem is the result of a moisture problem, the first step in mold cleanup is identifying the origin of the moisture or water intrusion and remedying it completely. Leaky roofs can be caused by missing or damaged shingles, cracked or damaged rooftop vents, missing flashing, or a deteriorating chimney, among other things. Bypass (air leakage) around light fixtures, wires, or flues into the attic are another frequent cause of moisture; gaps or holes surrounding these provide passage for the warm, moist air from your home to travel upward into the attic, where it can condense and elevate relative moisture. Disconnected venting, particularly from clothes dryers or bathroom vents, allows hot and humid air that should be exhausted outside to be expelled into the open attic space, creating conditions extremely favorable to mold growth. Once the source of moisture has been identified and corrected, the remediation process can begin.


The attic mold remediation process (in a nutshell)

Before beginning remediation, the affected area is sealed off from the rest of the home with polyethylene sheathing and placed under negative pressure with the help of a negative-air machine. This practice prevents contamination of other areas of the home. Once this has been accomplished, the removal of mold from affected areas can begin. Insulation is discarded, and visible mold is removed from all surfaces. This can be accomplished with abrasive methods, such as dry-ice blasting or soda blasting, or with chemical methods such as MMR or RMR. Every surface is then contact-vacuumed with a HEPA-vacuum to remove mold spores. A fungicide is applied to every surface, to kill mold spores and prevent regrowth. Finally, every surface is again contact-vacuumed with a HEPA-filter vacuum, removing any remaining mold spores.


Encapsulating to inhibit future growth

Once all mold has been removed from surfaces, homeowners may choose to apply a product known as a mold encapsulant to protect non-porous surfaces from regrowth. Some products used for this purpose are Foster 40-51 or Fiberlock AfterShock. Encapsulants are applied in a manner similar to painting and work both to protect a cleaned surface and leave it less fertile to regrowth, as well as to seal in and render immobile smaller particles that could not be removed. 


An ounce of prevention . . .

Of course, preventing a problem is almost always easier and less expensive than remedying one, especially where homes are concerned. To pre-emptively guard against mold growth in your attic, ensure that your roof, chimney, and any associated flashing are well-maintained. Address any air leakages around recessed lights, wires, vents, or flues with caulk or other appropriate measures. Fortunately, DIY tutorials abound on this subject. You'll also want to ensure that none of your HVAC systems vent inside the attic. HVAC cleaning technicians regularly ensure proper air flow after cleaning a dryer or bathroom vent and consequently have saved lots of homeowners from potential damage in that regard.

Wanna learn more about mold testing, remediation, and inspection? Visit our mold services page.

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Thanks to our mold remediation specialist Zach C for lending his expertise to this article.


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