When a warm sunny day arrives after a long cold stretch and it seems like you have a roof leak when there isn t a cloud in the sky it s probably attic icing otherwise known as ice dams or ice damming and the surprising thing is that it s very unlikely that the roof covering itself is the problem.
Frost heaters in attics.
Frost and ice forms in attics when warm humid air accumulates and condenses on the underside of your roof sheathing.
To start frost shows up in the attic when moisture laden air from the house gets into the attic.
I ve blogged about attic air leaks many times and i ve shared photos of attic air leaks.
When the moisture gets into the attic it condenses on the roof.
Why it s there and how to fix it by reuben saltzman in study guide energy frost in attics new on january 9 2018 if you have a problem with frost in your attic you re not alone.
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.
Frost gets into the attic from air leaks or attic bypasses.
Frosty roof deck nails and sidewall.
That s about it pretty simple.
When the outside temperature rises again the frost thaws water collects and can leak into your house.
Check out my post on moldy attics for some.
Over that third unit from the left there s little heat getting into the attic as evidenced by the unmelted snow.
In cold climates that leads to ice dams.
All of these anomalies are a sure sign that condensation from heat loss is an issue.