Causes of Attic Mold

attic moldA visit to your attic may be an uncomfortable experience for you. For attic mold growth, however, the darkened, stuffy confines just the other side of your ceiling offer the perfect environment. Moreover, since most homeowners spend as little time as possible up there, mold may gain a substantial foothold before it’s discovered. A mold-contaminated attic can become an ongoing source of microscopic airborne spores that spread active mold growth throughout the house, triggering chronic allergic reactions and illness in many people.

Why are attics often ground zero for mold growth and what can be done to prevent it? Since dormant mold spores exist virtually everywhere, active mold growth generally requires just three more elements:

  • A dark area shielded from sunlight.
  • Some source of cellulose-based food.
  • A little moisture such as dripping water or even just chronic high humidity.

Attic spaces generally receive no sunlight whatsoever. The food supply is often abundant as exposed wooden structure provides cellulose (mold will even eat the paper backing on attic insulation.) Finally, roof leaks, as well as water vapor rising up from the living spaces below, create the moist, humid environment vital to thriving mold growth.

To make your attic less mold-friendly, here are some suggestions:

  • Have the roof inspected and repair any leaks.
  • Ensure the attic gets adequate outdoor ventilation to reduce accumulation of humidity and heat that promote mold growth. Check attic vents at the soffits and up at the roof peak to verify they are open and unobstructed by insulation or items stored in the attic.
  • Seal any cracks or gaps in the ceiling of rooms below with caulking to stop migration of water vapor and heat into the attic. Look for cracks along the joint between the walls and ceiling. Light fixtures recessed into the ceiling may also include gaps that allow air exchange with the attic. Make sure weatherstripping around pull-down attic stairs or access hatch is intact.


Tags: , , , , ,

Return to the Blog Home Page