Roof Boards Damp

It is never a good idea to install a roof over wet plywood or any type of roof sheathing.

Roof boards damp.

Such cookers often allow for the quick rise of moist air leaving behind the cold air. When this warm air reaches the spaces in the roofs it gets in contact with cold air and condenses. This occurs when the temperature of the sheathing drops below the dew point creating a thin layer of moisture on the substrate. Mold growth on attic roof sheathing is a common issue in cool climates such as the pacific northwest.

Look for damp spots on the underside of your roof. Roof cuts and thermographic imaging can also detect moisture in addition to other strategies. On structural concrete and possibly wood planks or plywood moisture drips may not be observed. In the vast majority of cases the mold growth is caused by condensation.

The osb and in fact any wood panels must be allowed to dry completely depending on how wet the panels are this could be a few days before any roofing material is applied to avoid trapping moisture under the roof material that could cause edge swell and buckling. Follow the water uphill till the wood is no longer wet. Trapped water will boil when the sun heats the roof and the shingles will then have small pits where the. Look for potential entry points like roof vents valleys loose nails and mark the area with chalk so you can examine the exterior of your roof after it quits raining.

Also look for a thin stream of water flowing down one of the rafters.