Particularly in cold climates when homeowners heat their homes in winter hot air tends to escape through the attic.
Mold in roof attic.
Click photo for larger image.
Heating ventilation and air conditioning ducts may also.
Wooden beams and plywood may be affected and it can be difficult to remove all traces of mold from wooden surfaces.
Mold growth on attic roof sheathing is a common issue in cool climates such as the pacific northwest.
The chief cause of attic mold is poor ventilation.
Attic mold left unchecked can grow and lead to structural deterioration of attic sheathing and roof structural elements.
The mold shown in the attic photographed above was identified as aspergillus sp.
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.
There s an underlying moisture issue that needs to be resolved because mold requires moisture to grow and spread.
This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate.
Insulation is often affected.
This occurs efficiently in attics with proper ventilation but attic mold can occur if the hot air meets the cold surface of the attic roof and creates condensation.
In the vast majority of cases the mold growth is caused by condensation.