Attic Sheathing Black

If the dark surface of the wood smudges it could be mold.

Attic sheathing black.

Mold growth on attic roof sheathing is a common issue in cool climates such as the pacific northwest. Even in this case in our opinion the reasons to remove and replace roof sheathing and framing would normally be based on the condition of the roof framing and sheathing not on the presence of mold or stains. If the wood is soft if it s easily imprinted when you push on it it s probably rotten. Despite what your roofer would like you to believe roof leaks rarely cause significant mold problems.

The mold itself may have a cottony texture but can also be velvety leathery or. The other two possibilities for the stains. The following picture is of a long standing moisture condition in an attic where much of the roof sheathing has turned black. In our roof interior attic photo at left you can see antique roof framing along with black stains and probably some mold growth from a long history of roof leaks.

I have surface mold on the sheathing in my 1982 vintage 12 6 pitched attic. Uniform black mold growth on attic sheathing. This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate. White and green fuzzy growth on osb sheathing.

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. In many cases the continued wetting of the sheathing will cause it to rot but that may take several years or decades depending on the attic ventilation. In old houses you ll usually see some spots that are stained dark or black where there was a roof leak at some point in time which was repaired but the stain remains. When moisture condenses on plywood roof sheathing repeatedly or continuously the wood will turn black.

In the vast majority of cases the mold growth is caused by condensation. I m aware of the cause poorly vented bathroom fans and not well sealed fan fixtures lights wires etc.