Posted on January 14, 2010 by
Daniel Morrison, GBA Advisor
When northern builders see icicles, they think “ice dam.” Heat from the living space leaks into the attic and melts snow on the roof; the water runs down the roof until it gets to the colder eave, where it freezes. When water backs up behind the ice dam at the eave, it can get under the shingles and leak into the interior.
In the north, icicles are often a sign of trouble.
In New Orleans, however, there is usually no snow to melt. Icicles coming out of a roof here represent something different. But they are still trouble.