Black Spots On Plywood In Attic

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 spots on plywood in attic.

The mold itself may have a cottony texture but can also be velvety leathery or. 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. It usually appears greenish black and streaky. Based on the reading i ve done on this site i have learned that the double stud wall system can cause condensation problems on the inside of the plywood sheathing.

Mold usually causes a musty odor and may cause staining that may be black brown gray white yellow or green. If you re not sure what you re looking for here s a picture of mold in an attic. However there are many different types of mold so if the mold in your attic looks different that does not mean you don t have a problem or don t need to worry about it or take action. After several years of this there may be.

If the wood is soft if it s easily imprinted when you push on it it s probably rotten. This can be caused by the action of fungal growth and molds and the affect they have on the tannins in the wood. I did some investigating this august and sure enough i noticed a few black mold spots on the inside of the plywood. When moisture condenses on plywood roof sheathing repeatedly or continuously the wood will turn black.

Walls that are improperly insulated may develop mold because they will absorb moisture from outside. The following picture is of a long standing moisture condition in an attic where much of the roof sheathing has turned black. Without proper ventilation in the attic high heat and humidity can build up which leads to moisture from a different source. In the attic the most common places to find black mold are the places where water is likely to be a problem.

Black mold in attics. These are commonly seen underneath roof vents plumbing stacks vent hoods. 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.