Mold cannot grow in attic insulation, but it can grow on and around it. Fiberglass insulation is not a viable food source for molds, and cellulose is usually treated to prevent mold growth. This guide explains how mold accumulates around insulation and how to prevent it.

Mold Growth on Attic Insulation

Mold requires moisture and a food source, and the paper vapor retarder attached to fiberglass insulation can grow mold. If you were to go up into the attic right now and look at the insulation, you may find a gray or black layer of mold, but it is probably dead. Mold will grow on the roof of the attic from condensation, and when the attic gets extremely hot, it kills the mold, which falls on top of the insulation. This dead mold, as well as dust, is a viable food source for new spores. If a water pipe breaks in the attic or the roof leaks, the fiberglass will absorb the water. Although the insulation is safe, the wood beams around the insulation will eventually absorb some of the water and give mold a new home.

How to Prevent Moisture

Moisture can accumulate over time through condensation. If air conditioner ducts are in the attic, and the airflow is inadequate, condensation forms. This is due to the warm air coming into contact with the cold metal. Too much insulation in the attic causes a similar problem. If the insulation is trapping all of the warm air in the home, then the attic becomes the same temperature as the outdoor environment. As warm air slowly leaks into the attic, the roofing builds up condensation. Call a roofing contractor to maintain airflow and temperature in the attic or remove existing mold.

If you’re looking to upgrade your attic insulation or need it inspected for mold and proper ventilation, contact the experts at Ray St. Clair Roofing Inc.  For over 60 years, they’ve provided the Greater Cincinnati, OH, area with new gutters, windows, decking, and siding. Striving for a 100% customer satisfaction rating, they have their own quality control team that ensures every job is performed correctly. Visit them online to see why cellulose insulation is perfect for your home, or call (513)874-1234 to schedule an appointment.