Underside Of Roof Damp

That excess moisture ends up as drops of condensation on the roof.

Underside of roof damp.

Essentially condensation occurs at night when the temperature inside a building is warmer than outside. Warm air can contain more moisture than colder air. Picture a cloud of moisture floating overhead between the rafters. When humid air from the interior makes contact with the underside of the roof surface the water vapor it s carrying turns into liquid water explains jose f.

In the event of the attic not being properly ventilated this would condense on the underside of the roof. Think of a cold drink sitting out on a summer day. Another leading cause of condensation in roofs is the use of wood burner cookers. If attic air is humid and roof sheathing is cold condensation or frost can accumulate on the underside of the sheathing.

As it cools it can t hold as much moisture. This leads to the formation of damp spots on the surface of the roof. When this warm moist air hits the cold air in the roof space water droplets condense on the nearest cold surface the roofing felt. 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. Warm wet air rises and meets the cold roof and cools. Ponce technical specialist with professional roof consultants. The source of the attic moisture is usually indoor air that enters the attic through ceiling cracks.

The cause depends on whether you have an unconditioned attic or a conditioned attic.