Do you know if this product contains asbestos or a wood product.
Black markings on attic sheathing 2017.
This can be caused by the action of fungal growth and molds and the affect they have on the tannins in the wood.
The mold is likely coming from a condensation buildup along your soffet a good trick would be to get in there and attach cut foam blocks at the top of your wall cavity up to the roof deck to seal the soffet of from the attic space wherever cooler and warmer air mix there will be condensation.
After several years of this there may be.
Excessive humidity inside the house making its way to the attic where it then condenses on the structural members.
This summer i cleaned the portion of the black stain with a dry mop as much as i could reach from the hatch opening.
The following picture is of a long standing moisture condition in an attic where much of the roof sheathing has turned black.
When looking for attic mold trace both leak.
Mold on attic sheathing.
The photo at page top shows white attic mold on the roof sheathing and rafters and some brown or black mold on the attic side of ceiling drywall where we pulled back insulation.
This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate.
Mold growing on the sheathing in your attic is a serious problem that shouldn t be ignored.
Last winter i took a look into the attic and noticed black stains and water marks on a portion of the sheathing material.
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.
In the attic photograph at left we show a mix of green gray and white attic mold.
Doing some remodeling and we found this under the drywall georgia pacific regular sheathing ps 57 and astm c 208 black board.
Something else you can do to help is get.
The dark stains on roof sheathing can usually be traced to one of two things.
Fiberboard sheathing is a wood product.
Does mold on attic sheathing have to be removed.
In the vast majority of cases the mold growth is caused by condensation.