This can be caused by the action of fungal growth and molds and the affect they have on the tannins in the wood.
Black on sheathing in attic.
After several years of this there may be.
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.
In an attic this is typically your roof sheathing or framing.
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.
In the vast majority of cases the mold growth is caused by condensation.
This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate.
Homeowner is looking for advice on how to deal with black mold on the sheathing in the attic.
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.
The photo below illustrates where condensation comes from in an attic.
The insulation was contaminated and we inspected the attic side of the ceiling drywall below for signs of leak stains or mold.
Mold usually causes a musty odor and may cause staining that may be black brown gray white yellow or green.
The following picture is of a long standing moisture condition in an attic where much of the roof sheathing has turned black.
Mold growth on attic roof sheathing is a common issue in cool climates such as the pacific northwest.
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.
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.