Fixing this issue can be less costly than replacing a roof but it should be addressed as soon as possible.
Roof sweating in attic.
It s no surprise that this tends to occur more in colder months when home heating is more common and intense.
Mold growth on attic roof sheathing is a common issue in cool climates such as the pacific northwest.
Most people assume this is caused by a leaking roof but that might not be the source.
This could be a sign that your excessive indoor humidity is causing damage elsewhere in places you cannot see such as.
In the vast majority of cases the mold growth is caused by condensation.
The rapid cooling leads to immediate condensation.
During the winter months the recommended relative humidity inside a house is anywhere between 30 50 percent.
Finding water damage on the wall or ceiling is worrying for any homeowner.
Roof condensation has a very specific cause.
Moisture occurs when heated air inside the home rises up to the roof where it meets the colder temperatures of outside air.
Water found in these places is commonly caused by condensation in the attic.
If there is excessive moisture accumulation in your attic it will condense on cold areas mainly on the underside of your roof deck.
This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate.