CONCORD, N.H. — New Hampshire’s state fire marshal says with the recent snow and wind, there’s greater urgency to clear roofs of excessive snow and ice.
Bill Degnan says a roof may collapse with little or no warning, and one common misconception is that only flat roofs are susceptible to collapse.
He said the recent snowfall in combination with high winds may cause snow on one side of the roof to be clear and the other side to have a large drift, which causes an imbalanced load on the roof. That makes it more susceptible to collapse.
Degnan said that taking all the snow off one side, but not off the other, will have the same effect. The rule of thumb is that condensed saturated snow weighs about 20 pounds per cubic foot.