JLC • DECEMBER 1996 JLC • DECEMBER 1996/0
As a builder in the Northeast, where
cold, snow, and ice are the main
course on the winter menu, roof ventilation
is one of my top concerns. The primary
reason is that without good
ventilation, most roofs in snowy climates
will suffer from destructive ice dams.
I've chipped away at my share of ice
dams, and in my experience the cause is
always the same: Hot air is all dressed
up and has no place to go. Every house
ever built has heat loss through the
roof. When air in a rafter bay is
warmed, it's natural for it to rise. If it
can't escape, it's going