This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate.
Fungus on roof sheathing.
A timely article as we are experiencing mold on our attic sheathing in our portland.
Next mix 1 quart of bleach 1 gallon of water and cup of trisodium.
Then use a long handled brush to scour the surface of the shingles and loosen stuck on mold while it s dry and brittle.
To clean mold off a roof start by putting on rubber gloves a breathing mask and goggles to protect yourself from the harsh cleaning chemicals.
Cleaning the sheathing kills the mold and prevents it from producing spores.
Mold that grows on the underside of roof sheathing due to ideal mold growth conditions being present.
It was built in 1978 and when we bought it a couple of years ago the roofing was replaced as part of the sale agreement along with a couple sheets of roof sheathing additional round 3 soffit vents put in and mold mitigation.
Generally tearing off a roof and roof sheathing and perhaps roof framing to remove mold would not be sensible nor cost justified.
Mold growth provided it is not just cosmetic mold which can simply be left alone can be cleaned from wood surfaces by blasting scrubbing or even simple surface wiping depending on the surface accessibility and.
Mold on attic sheathing.
Mold on the underside of roof sheathing is also very common.
The presence of mold in your attic is often the result of poor ventilation insufficient insulation moisture from a roof leak or improper venting from your bathrooms or kitchen.