Green Mold On Underside Of Roof Sheathing

Mold that grows on the underside of roof sheathing due to ideal mold growth conditions being present.

Green mold on underside of roof sheathing.

In most cases the moisture that causes the condensation on the roof sheathing is from occupant activity in the home below. This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate. Generally tearing off a roof and roof sheathing and perhaps roof framing to remove mold would not be sensible nor cost justified. 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.

When it s cold enough outside water vapor in an attic with improper ventilation can freeze on the underside of your roof. Frost buildup on the underside of the roof sheathing in winter. Mold growth on attic roof sheathing is a common issue in cool climates such as the pacific northwest. In the vast majority of cases the mold growth is caused by condensation.

One puzzling aspect of the phenomenon is that the mold is found in well built homes that comply with all relevant building codes. Mold usually causes a musty odor and may cause staining that may be black brown gray white yellow or green. Due to the stack effect warm air rising this moisture slowly migrates toward the attic. After several years of this there may be.

Mold on the underside of roof sheathing is also very common. Mold growth provided it is not just cosmetic mold which can simply be left alone can be cleaned from wood surfaces by blasting scrubbing or even simple surface wiping depending on the surface accessibility and. There s an underlying moisture issue that needs to be resolved because mold requires moisture to grow and spread. Showering cooking laundry even just breathing adds water vapor into the air.

While this is easy to spot by the time you see it mold may have already begun to grow. This phenomenon occurs in vented attics and is more common in new homes than old homes. Increasingly homeowners in the pacific northwest are noticing mold on the underside of their roof sheathing. The presence of mold in your attic is often the result of poor ventilation insufficient insulation moisture from a roof leak or improper venting from your bathrooms or kitchen.