This latter phenomenon occurs when the house is too humid and the warm moist air seeps into the attic where it condenses and freezes on cold attic areas.
Black on sheathing in attic.
These are commonly seen underneath roof vents plumbing stacks vent hoods.
Mold growth on attic roof sheathing is a common issue in cool climates such as the pacific northwest.
The insulation was contaminated and we inspected the attic side of the ceiling drywall below for signs of leak stains or mold.
This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate.
After several years of this there may be.
In an attic this is typically your roof sheathing or framing.
The black attic mold shown here confirms that this attic had a serious venting and moisture problem including moisture from sources lower in the building.
In the vast majority of cases the mold growth is caused by condensation.
The mold itself may have a cottony texture but can also be velvety leathery or.
This can be caused by the action of fungal growth and molds and the affect they have on the tannins in the wood.
Mold usually causes a musty odor and may cause staining that may be black brown gray white yellow or green.
Usually you cannot see the individual droplets unless there is an exposed area of metal or the outside temperature is especially cold.
Homeowner is looking for advice on how to deal with black mold on the sheathing in the attic.
Roof leakage can often be seen as dark black stains concentrated and radiating out from one or more individual locations.
The following picture is of a long standing moisture condition in an attic where much of the roof sheathing has turned black.
The photo below illustrates where condensation comes from in an attic.