Mold On Roof Sheathing

This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate.

Mold on roof sheathing.

This phenomenon occurs in vented attics and is more common in new homes than old homes. Mold growth on attic roof sheathing is a common issue in cool climates such as the pacific northwest. So a house that we are in contract to buy just came back with mold in the attic sheathing of the roof. If you don t find the source of the moisture in your attic and fix the problem it will only get worse.

He believes that poor ventilation was to blame and that by installing a ridge vent would prevent any. Where do you go from here. Mold can weaken structural elements of your home like the rafters and roof sheathing. This condition may be consistent with the effects of night sky radiation.

It s covering the rafters and the roof sheathing and there s even some stuff on the insulation. There is some staining discoloration and or mold or mold like fungal growth present on the roof sheathing in the attic. The inspector noted that the mold wasn t on the rafters. One puzzling aspect of the phenomenon is that the mold is found in well built homes that comply with all relevant building codes.

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. Because wood is porous it may be difficult to remove the mold stains from sheathing but you can kill the mold by cleaning the sheathing with bleach and water. After several years of this there may be dark rings around protruding roofing nails and larger dark spots or areas on the roof sheathing and or exterior gable walls. And it seemed to be localized to one side of the sheathing not the other.

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 smoothness. There are many different species of mold and only lab testing can confirm the particular type of mold in any given. In the vast majority of cases the mold growth is caused by condensation. Another common concern with mold in the home is exposure to airborne mold spores.

Mold that grows on the underside of roof sheathing due to ideal mold growth conditions being present. Generally tearing off a roof and roof sheathing and perhaps roof framing to remove mold would not be sensible nor cost justified. Increasingly homeowners in the pacific northwest are noticing mold on the underside of their roof sheathing. Mold can form but often it is.