A commercial complex in Easton was reduced to rubble recently when its roof collapsed under the weight of snow. So far, 183 roofs have collapsed in the state this month, officials said. (Jonathan Wiggs/Globe Staff)
By Peter Schworm and Scott AllenGlobe Staff / February 13, 2011
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State regulators are collecting detailed damage reports from this month’s unprecedented number of snow-laden roof collapses, surpassing even the number reported after the Blizzard of 1978, to determine whether building standards should be updated.
In response to sharp public concern over the damage, inspectors are studying each of the 183 roof failures reported to state emergency officials, with a focus on schools, retail businesses, and newer structures bound by current construction standards, said Thomas Gatzunis, the state’s public safety commissioner.
“The Department of Public Safety is ensuring that all lessons that may be learned from the events of the past few weeks will be appropriately addressed in the building code,’’ said Charles McDonald, a spokesman for Gatzunis.
Stricter standards would affect only new construction, however, and Gatzunis noted that many of the collapses occurred in older buildings grandfathered from current requirements. The state can order improvements to older structures but does so rarely because of the high cost to owners.
A Globe review of the damaged properties showed that most were older commercial and industrial buildings, generally in parts of the state that received particularly heavy snowfall. Of the buildings whose age could be established through local tax information, 80 percent were constructed before 1975, the year the statewide building code went into effect.
Since then, the code has become progressively more stringent, with the latest version taking effect just last week.
Yet several relatively new shopping centers, including the Wrentham Village Premium Outlets and Lincoln Station mall, also sustained roof damage, as did schools in Georgetown and Hingham. Nearly 60 residential structures were also damaged.
In Easton, a large office complex was reduced to rubble, crashing to the ground like a house of cards. In Georgetown, a section of an elementary school’s roof collapsed, with catastrophe averted only by an underlying layer of concrete. In Lynn, a pair of men spent two hours trapped inside a parking garage after the steel roof collapsed around them.
Despite a number of close calls, no one was seriously injured, but the scope of the damage has focused public attention on the problem and what should be done about it.
Massachusetts raised the weight-bearing requirement for new commercial and residential roofs just three years ago. But Gatzunis said he is open to strengthening the standards again to help structures withstand severe winters. On many flat-topped commercial and industrial buildings, the weight of the snow far exceeded the minimum standards, he said.
Under the current standards, new commercial roofs must be able to carry 45 to 65 pounds of snow per square foot, depending on typical snowfall in the area. Three feet of dense snow and ice could easily exceed that, inspectors say. In Easton, for instance, sections of one collapsed roof were carrying more than 100 pounds of snow per square foot.
It was like looking at geological layers,’’ said Mark Trivett, the town’s building inspector. “You could see each successive storm, piled on top of each other.’’
Gatzunis said the state could also mandate that commercial buildings install sensors that can detect when a roof is beginning to sag. Roofs on residential homes are generally sturdier because they are often sloped, making it easier for snow to slide off.
With the images of cave-ins splashed on the nightly news, worried property owners have scrambled to hire snow removal crews, or rushed to buy roof-rakes or snow-melting chemicals.
Springfield was the site of the most collapses, with 11, followed by Boston, with 10. Avon, Lawrence, Worcester, Chelsea, and Somerville all had at least four damaged roofs, according to the Globe’s review.
The collapses came after an unusual succession of intense snowstorms, followed by heavy rain that was absorbed by the snow, creating a dense mix. For many older, flat-topped buildings, the burden was too much.
“This is by far the most [roof collapses] I’ve seen,’’ said Walter Blair Adams, an independent building code consultant in the Boston area with more than 30 years of experience. “I don’t recall anything even close.’’
So far this winter, Worcester has received 77 inches of snow, compared with a season-to-date average of just under 40 inches. Boston has received 71 inches, compared with an average of about 45.
In addition, mild temperatures have been scarce, freezing the snow in dense, icy layers.
The extreme weather, even by New England standards, and the low probability it will occur again soon, caused many inspectors to downplay the need for more regulation.
“This isn’t going to happen every year,’’ said Peter Blanchette, building commissioner in Lawrence, where several older, wooden-framed roofs gave way. “And I don’t think it’s the construction as much as public awareness. People need to know they need to remove snow when it gets to a certain point.’’
Local inspections of commercial properties, Blanchette and others said, will only take note of roofs that have visibly deteriorated.
“We’re not engineers ourselves,’’ he said. “It’s not something you can look at and see whether it’s going to hold under a lot of snow.’’
Others doubted that increasing the building standards for snow would do much good.
“It’s easy for us on advisory boards to say, ‘Gee it’s going to make the building safer, so we should require it,’ ’’ Adams said. “But it’s also important to figure out if we’re overloading the building owners with costs.’’
But others welcomed tighter regulations, and some local inspectors pledged tougher oversight of commercial properties.
“We have to plan for this,’’ said Scott Lambiase, building commissioner in Duxbury. “If we feel a building poses a hazard, we are allowed under the building code to make it safe.’’
In the future, home and business owners should realize they need to remove snow before the piles become dangerously high, inspectors said. “We have to let them know you don’t want to wait,’’ Lambiase said. “The longer you wait, the worse it gets.’’
Chris Sheppard, a partner at an insurance agency in Brockton, said insurance companies have traditionally paid little attention to the possibility of roof collapses because they have been relatively rare. After this winter, that may change. “The assumption is that it’s not going to collapse,’’ he said. “But I think this may be a wake-up call.’’
In Springfield, building commissioner Steven Desilets, said regulation is no substitute for personal responsibility.
“Let’s face it, there was a lot of warning that this could happen,’’ he said. “People need to be vigilant about it, especially now that they’ve seen what can happen.’’
© Copyright 2011 Globe Newspaper Company.