Assuming the area of mold growth is fairly small the mold growth can be scrubbed off with a detergent water solution.
Will mold just wipe off roof sheathing.
If the surface is too porous to remove mold completely such as in ceiling tiles you may have to replace it.
This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate.
This article offers advice on cleaning mold found on surfaces of un finished wooden building materials such as framing lumber rafters floor joists wall studs and building roof wall and floor sheathing such as plywood tongue and groove pine boards and other structural wood surfaces in buildings.
Mold on attic sheathing.
Scrub mold off hard surfaces such as window sills and tile with detergent and water and dry completely with a rag.
For more porous surfaces like drywall just use a rag so you don t damage the surface with more abrasive cleaners.
In time the mold will simply grow on top of the new dust that settles on top of the cleaner coating.
Do not apply the solution to a porous material such as drywall.
Prevent future mold growth.
To clean mold off a roof start by putting on rubber gloves a breathing mask and goggles to protect yourself from the harsh cleaning chemicals.
In the vast majority of cases the mold growth is caused by condensation.
Mix a solution of one part bleach to three parts water in a spray bottle and thoroughly saturate the moldy areas of the wall.
Open a window and or keep a fan.
Best procedures for cleaning mold contaminated wood.
If there is a leak in the roof plumbing or windows the mold will reappear if the water is.
Mold growth on attic roof sheathing is a common issue in cool climates such as the pacific northwest.
Generally tearing off a roof and roof sheathing and perhaps roof framing to remove mold would not be sensible nor cost justified.
Then use a long handled brush to scour the surface of the shingles and loosen stuck on mold while it s dry and brittle.
Wipe the area off and make sure it dries thoroughly.
After you apply the borax solution scrub the area with a rag or a wire brush until the mold is gone.
Remove mold stains from walls.
No chemical can prevent mold growth if elevated moisture is present.