Black On Underside Of Roof

The mold itself may have a cottony texture but can also be velvety leathery or.

Black on underside of roof.

Warm wet air rises and meets the cold roof and cools. This can be caused by the action of fungal growth and molds and the affect they have on the tannins in the wood. Essentially condensation occurs at night when the temperature inside a building is warmer than outside. At the south end of the roof the ridge changes direction causing an overlay condition.

The black mold is on the first 3 truss panels. Skips a few trusses and reappears on the next panel or two. Roof leakage can often be seen as dark black stains concentrated and radiating out from one or more individual locations. Picture a cloud of moisture floating overhead between the rafters.

Mold growth on attic roof sheathing is a common issue in cool climates such as the pacific northwest. This can be a problem for many homeowners and needs to be addressed as soon as it is found to avoid the consequences it can bring. This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate. After several years of this there may be.

The roof has baffles at alternating thusses soffit and ridge vents. When moisture condenses on plywood roof sheathing repeatedly or continuously the wood will turn black. Mold requires a few key elements in order to grow and thrive. As it cools it can t hold as much moisture.

Organic materials to feed off moisture warmth and darkness. In the vast majority of cases the mold growth is caused by condensation. These are commonly seen underneath roof vents plumbing stacks vent hoods. A 10 x 10 area of plywood has been removed to provide air into this area.

Mold usually causes a musty odor and may cause staining that may be black brown gray white yellow or green. The following picture is of a long standing moisture condition in an attic where much of the roof sheathing has turned black. Mold that grows on the underside of roof sheathing due to ideal mold growth conditions being present.