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.
Mold on osb in attic.
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.
Attic mold cleaner attic mold removal how to clean attic mold how attic mold gets there in the first place and what to do to help prevent attic mold.
The most common cause of attic mold by far is blocked or insufficient ventilation of the attic space.
On attic mold visible on pine tongue and groove roof sheathing near the building eaves.
Water leaks are another common cause of attic mold.
The attic is truss framed with plywood sheathing.
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.
Click photo for larger image.
Mold growing on the sheathing in your attic is a serious problem that shouldn t be ignored.
In the vast majority of cases the mold growth is caused by condensation.
Mold is a common problem in moist areas or places that are prone to flooding or leakage.
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.
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.
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.
The mold shown in the attic photographed above was identified as aspergillus sp.
The roof has baffles at alternating thusses soffit and ridge vents.
This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate.
The white blown in insulation was used.