Frost In Attic During Winter

So what is causing all of these leaks during the winter if it isn t rain snow or ice.

Frost in attic during winter.

The air in the attic has water in it and it condenses on the cold metal. This is why you see the frost. Frost accumulates in attics when moisture laden air from the house gets up there when it s cold. During winter conditions attic frost is a problem associated with attic bypasses.

During winter there are usually three sources of humidity in an attic. 1 a leak 2 air infiltration from the living spaces and 3 incorrect venting of kitchen bathroom washer drier or plumbing vents. When warm air from inside the house escapes traveling up through the bypasses the moisture condenses on the roof boards and rafters where the frost can form. Most homeowners never look in their attic spaces and if moisture is present slowly but surely it can cause damage without the homeowners knowing about it.

This winter s frigid weather in alberta could trigger more cases than last year of attic rain when warm moist air sneaks into the attic freezes then melts in warm spells like chinooks. This winter warmer dryer weather has seen the return of more normal attic conditions with significant frost seen only in problematic attics. When the moisture gets into the attic it condenses on the roof. The resulting thick layer of frost remained for several weeks until the weather warmed or a reasonable layer of snow covered the roofs to provide some insulation from the very cold exterior temperatures.

The one common denominator that we found was frost or moisture in the attic space. This will freeze if attic temperatures remain below freezing causing frost to build up. If there is excessive moisture accumulation in your attic it will condense on cold areas mainly on the underside of your roof deck. When the outside temperature rises again the frost thaws water collects and can leak into your house.

A point often overlooked is that since it s winter the water freezes on the cold nails. During the winter months the recommended relative humidity inside a house is anywhere between 30 50 percent. That s about it pretty simple.