My Attic Has Frost

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.

My attic has frost.

During winter conditions attic frost is a problem associated with attic bypasses. Many people s first instinct when they notice frost in the attic is to add insulation. If it s due to air infiltration from the living space then air sealing should be the first thing you do not the last. To start frost shows up in the attic when moisture laden air from the house gets into the attic.

Where the water comes from. Attic frost is the result of conditioned air leaking out of your home in the winter. A bathroom vent has been left to pump warm air into the attic. The exhaust from the rooms below gets released into the open air in the attic if not sealed properly causing lots of moisture in the air.

That s about it pretty simple. Therefore my suggestion is that if one finds frost in the attic one first has to identify which of the three causes is contributing to the problem. Frost in your attic space is a sign that warm humid air is somehow getting into your attic space. Since our minnesota winters are usually dry the only other source of humid air is your living space.

So the short answer is yes this is something you should fix. When the moisture gets into the attic it condenses on the roof. Insulation is irrelevant when your attic bypasses are left open for warm air to pour into the attic. See the picture above.

That is not a solution.