Big snow piles put heavy burden on New England roofs

SUTTON, Mass. -- The roof of a shopping plaza in Massachusetts collapsed Wednesday afternoon under the weight of heavy snow drifts, CBS Boston station WBZ-TV reports.

Earlier in the day, a partial collapse at the plaza closed several businesses and the post office, police in Sutton told WBZ-TV.

Police said there was a "complete roof failure" at the plaza. Officials had expected the roof to collapse and evacuated the businesses.

No building is safe from the incredible stress of the 8 feet of snow that has piled up on roofs across New England, and things are expected to get worse before they get better, experts said Wednesday.

The Massachusetts Emergency Management Agency has received 74 reports of roof collapses, partial collapses or major structural issues since Feb. 9, and that doesn't account for those that have not been reported, spokesman Chris Besse said.

In New Hampshire, more than 500 residents were displaced after two partial collapses at an eight-building apartment complex in Portsmouth, and schools in Epping and Newton were closed Tuesday after cracks appeared in the walls.

"I expect we'll hear of a lot more once the weather starts to warm up," said Garrick Goldenberg, a professor of structural engineering at Wentworth Institute of Technology.

No deaths or major injuries have been reported.

The problem is that repeated snowstorms compact the snow already on roofs, gradually turning it into ice, which weighs about eight times more, Goldenberg said. A cubic foot of snow that weighs about 8 pounds becomes a 64-pound cubic foot block of ice, he said.

Most of the collapses are occurring in flat-roofed buildings, but even pitched roofs are not safe under such stress. Commercial buildings, workshops, homes, garages and schools have been damaged.

A portion of the roof at North Attleborough High School came down and a brick wall buckled under the weight of snow on Tuesday, though just a few staff members were inside because it's vacation week for Massachusetts public schools. The roof of a Bridgewater elementary school was also damaged.

A Big Kmart in Braintree and a Burlington Coat Factory in Revere were evacuated and closed because of roof damage, and the public library in Whitman was closed when ceiling tiles fell and inspectors found bent roof trusses.

Goldenberg said it's not building codes that are inadequate, but maintenance. Snow should be removed as soon as possible.

"As soon as the snow stops, the best way to deal with it is to remove it immediately," he said.

And if you suspect a weakening roof, don't hesitate, Massachusetts Public Safety Commissioner Thomas Gatzunis said.

"Obviously, if you think the roof is about to collapse, get out and call 911, don't try to investigate on your own," he said.

Although the emergency management agency doesn't keep year-to-year roof collapse statistics, Besse and Goldenberg agree that this winter hasn't been as bad as 2011 when it comes to roof collapses, when the region experienced a similar series of winter storms.

Of course, there are a few more weeks left of this winter.