On Saturday night, the canopy covering gas pumps at Gibbs station gave way – a visible sign of the danger of allowing too much snow to sit on the roof, getting deeper with each snowfall.
The station canopy didn’t completely collapse, but will still be a chore for the owners to fix. Emergency public safety crews stood by Saturday night clearing out the area and cordoned off the end of Hobart Street from near Charter Street out to Maple Street.
Town building and fire inspectors have been out checking on numerous roofs throughout Danvers in recent days, as the threat of collapsing roofs has become real while snow continues to pile up this winter. Flat roofs are typically the most at-risk, particularly warehouses or other buildings with such wide spans to cover, such as a mall or school building.
“It’s an unusual winter with an unusual amount of snow,” Acting Fire Chief Kevin Farrell said.
Over 70 inches of snow for Danvers, in fact – 46 falling in January alone – and that’s causing problems – particularly on buildings that have older structural roof supports called purlins, said Farrell. As opposed to steel trusses, steel purlins are not as thick – about the size of a two by four – and not as durable under large loads of weight, he said.
Farrell and Building Inspector Richard Maloney and their inspectors have been focusing on factories and warehouses in town or other large retail outlets such as Walmart, Home Depot, the Liberty Tree Mall and checking on town schools. They said the School Department has been proactive about keeping its roofs clear of large drifts as snow rapidly built up over January, leaving a foot on most of those roofs.
Maloney said the Department of Public Works cleaned all the roof drains and scuppers on the school buildings and inspectors would be checking the schools again over the weekend.
Some neighboring school districts have had to cancel multiple days of school in the past week, however – in addition to storm cancellations – to remove snow.
“We’ve been to a lot of buildings in the last two days,” Maloney said on Friday, noting many businesses in town have worked proactively to avoid any problems, particularly the mall over the past two weeks.
“People are doing a great job getting the snow off,” Maloney said.
But that’s not everyone has been quick enough to clear the snow.
Last week, the Fire Department evacuated the Ira Collision Center on Route 114 fearing that the facility’s roof, which spans over four acres of property, could fall soon if the snow wasn’t removed. The 1960s era facility uses purlins for its roof supports.
“They’re out of there until they get the snow (about 15 inches deep) off the roof,” Farrell said.
Maloney said the roof beams were visibly buckling and the stress could even be seen in the seams in the roof insulation inside the facility. Maloney said Ira was in the process of pricing out the job to remove the snow and hiring an engineer.
Aside from workers physically climbing out on the roof armed with shovels and other equipment to remove the snow, which Maloney felt could be dangerous at this point, another option would be to melt the two-foot layer of snow by heating up the roof, he said.
“I’d be leery about getting up there and walking around. It’s a delicate operation,” he said, adding that the sun and rain over the weekend likely helped somewhat.
Ira Collision Center did not return a call for comment on the situation.
The Fire Department also responded to a potential roof collapse at an office building on North Street Friday morning, but there was no immediate danger to occupants inside. Farrell said the property owner was working on removing a foot of snow and added he was surprised to learn purlins were used in the construction of the newer building as well, although not “shocking” since the weight-bearing load is much less than at a warehouse.
Farrell, offering a word of caution to property owners, said they should look out for large snowdrifts accumulating on flat roofs along with listening for creaking or banging noises.
“If the steel starts to bend, you’ll hear it,” he said.
Another sign would be if the sprinkler pipes started bending down from the ceiling, indicative of the heavy load above, he added.