Black Stains On Plywood In Attic

This summer i cleaned the portion of the black stain with a dry mop as much as i could reach from the hatch opening.

Black stains on plywood in attic.

When moisture condenses on plywood roof sheathing repeatedly or continuously the wood will turn black. 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. I m aware of the cause poorly vented bathroom fans and not well sealed fan fixtures lights wires etc. The following picture is of a long standing moisture condition in an attic where much of the roof sheathing has turned black.

While the plywood remains largely unaffected. You can remove small amounts of mold covering 10 square feet or less of attic sheathing yourself but if the mold growth covers more than 10 square feet you should contact a. This type of mold growth will not smudge or wipe off. While the black stains are either mould or just black dust from attic insulation settled on the.

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. Notice the dark staining in the first picture. First let s look at the source. I have surface mold on the sheathing in my 1982 vintage 12 6 pitched attic.

Last winter i took a look into the attic and noticed black stains and water marks on a portion of the sheathing material. Black mold in attics. If the dark surface of the wood smudges it could be mold. This can be caused by the action of fungal growth and molds and the affect they have on the tannins in the wood.

You have mold that should be removed. Dark black staining on wood surfaces if the wood in your attic shows any black discoloration the problem has moved beyond moisture. In winter moist air is transported from the heated area of the home into the unheated attic space where it not only settles on the wooden rafters and plywood roof sheathing but also melts the snow on the roof leading to ice dams. Attic feels excessively hot or stuffy attics should feel breezy if they are properly ventilated.

Some spots are just patches here and there and others are big areas. I have obvious moisture stains in the attic and the roof.