During winter conditions attic frost is a problem associated with attic bypasses.
Frost in attic north side.
That s about it pretty simple.
To start frost shows up in the attic when moisture laden air from the house gets into the attic.
As to the frost there are a few things you can check.
Obviously the frost is caused by moisture in the attic air.
Upon inspection of the attic the entire north face of the attic had frost on the nails poking through and most of the decking boards.
The sun will sometimes warm the south side enough to thaw and evaporate moisture but leave it still coated on the north side again not a problem unless the ice starts to build up.
We still have one area in the rafters between the bathroom and a walk in closet that has some frost.
How much frost should you have in an attic.
You can t fully eliminate that moisture but you can try to limit it.
On the vapor barrier the insulation should be labeled at least an r 30.
In most cases rolled or batt insulation will have a vapor barrier already attached.
A few years ago we had a lot of frost and a company came in and charged us 250 to spray the exhaust fan and duct to stop leakage.
In some cases frost will form on the northside of the attic sheathing and not the south.
If you re further baffled by frost forming on one side and not the others you re probably looking at the north side.
If left untreated it can damage critical structural elements of the home such as the trusses and rafters ruin insulation damage any stored belongings and lead to the formation of potentially toxic black mold.
During the day as the sun is out in certain circumstances it will produce enough heat to warm the south side and allow it to thaw and evaporate moisture but the north side will still have frost as it does not get warm enough to cause evaporation.
When the outside temperature rises again the frost thaws water collects and can leak into your house.
You can prevent these problems from occurring by maintaining a dry attic with a low relative.
When the moisture gets into the attic it condenses on the roof.
There was also frost on the west wall on the north side of the dormer where the sun doesn t get to it this time of year.
There is no snow on the roof.
The frost is on the north side since the south side receives more sunlight over the course of the day during winter in the northern hemisphere.
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.
