Dark Plywood In Attic

The other two possibilities for the stains.

Dark plywood in attic.

Mold spores penetrate the plywood in your attic and it is difficult to completely eradicate it. Below is an image of heavy 3 dimensional mold growth on the sheathing. 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 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.

Black mold in attics. 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. Beneath the fuzzy growth areas of staining can be observed as well. When moisture condenses on plywood roof sheathing repeatedly or continuously the wood will turn black.

The following picture is of a long standing moisture condition in an attic where much of the roof sheathing has turned black. This can be caused by the action of fungal growth and molds and the affect they have on the tannins in the wood. In this photo of very dark mold in an attic in a wet attic mold which we found to be brown in the microscope looked black on the plywood. The dark discoloration will remain long after the mold has stopped growing.

Learn the real causes of mold growth on attic roof sheathing and what you can do to remove it for good. There is also a small risk that comes with applying the mold protective sealant in that the sealant can trap moisture in the plywood which will cause it to decompose and decay. If the wood is soft if it s easily imprinted when you push on it it s probably rotten. If your attic joists won t bear the weight necessary to finish out a living space but the engineer cleared them to support floor decking for light storage you can install inch plywood or.

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.