Mold On Osb In Attic

On the east side only there is black mold for the first 6 up the slope.

Mold on osb in attic.

Mold growing on the sheathing in your attic is a serious problem that shouldn t be ignored. Mold is quite dangerous and full exposure to it should be avoided at all costs. Click photo for larger image. The attic is truss framed with plywood sheathing.

This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate. Since osb is a cellulose based material most of the time it already contains mold spores and only requires moisture to trigger the growth process. On attic mold visible on pine tongue and groove roof sheathing near the building eaves. Mold is a common problem in moist areas or places that are prone to flooding or leakage.

Mold growth on attic roof sheathing is a common issue in cool climates such as the pacific northwest. Also notice the condensation stains at the shingle nail more evidence of a history of attic moisture which was a factor in this mold growth. The mold shown in the attic photographed above was identified as aspergillus sp. The white blown in insulation was used.

Water leaks are another common cause of attic mold. Attics usually have a passive ventilation system in which outside air comes in through the soffit eave vents at the bottom warms up in the attic and escapes through the can or ridge vents at the top because hot air rises. We had an inspection done on a home that we made an offer on and they found a small roof leak by the ventilation fan in laundry room which is causing mold. The presence of mold inside your home even if it s in an unused place such as the attic can cause.

In the vast majority of cases the mold growth is caused by condensation. A slow leak through the roof for example can feed mold colonies on the underside of the roof decking on the rafters and in the part of the ceiling insulation where the water eventually drips. If you re seeing mold growth on the walls and the attic it s either due to a roof leak or two completely separate issues.