After several years of this there may be.
Black on sheathing in attic.
The photo below illustrates where condensation comes from in an attic.
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.
When moisture condenses on plywood roof sheathing repeatedly or continuously the wood will turn black.
Usually you cannot see the individual droplets unless there is an exposed area of metal or the outside temperature is especially cold.
The mold itself may have a cottony texture but can also be velvety leathery or.
Mold growth on attic roof sheathing is a common issue in cool climates such as the pacific northwest.
Roof leakage can often be seen as dark black stains concentrated and radiating out from one or more individual locations.
This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate.
In an attic this is typically your roof sheathing or framing.
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.
Homeowner is looking for advice on how to deal with black mold on the sheathing in the attic.
These are commonly seen underneath roof vents plumbing stacks vent hoods.
I do not think the roofing is leaking there are gable end vents but no soffit vents they are looking to sell the house and do not want a problem with home inspector thanks.
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.
Mold usually causes a musty odor and may cause staining that may be black brown gray white yellow or green.