A month of relentless storms packing dense snow and heavy winds has left homeowners scrambling to stave off the risk of a roof collapse and prompted warnings on how to avoid one.
Yet more snow Wednesday morning pushed Boston past the 100-inch mark for the season, putting it within 8 inches of becoming the snowiest winter on record. And as the snow piled up this February, already the snowiest month in Boston history, so did the dangers to buildings.
More than 160 roofs have collapsed or faced imminent collapse since Feb. 9 in Massachusetts alone, the epicenter of this season's roof collapse epidemic, a Massachusetts Emergency Management Agency spokesman told NECN Wednesday. Most years see none. And New Hampshire has seen 10 collapses this year, the latest on Tuesday night, a spokesman for New Hampshire's agency said.
It's not just the amount of snow this month that's proven such a danger to roofs during this month's storms, experts say. It's the fierce winds that have piled it in drifts on roofs, along with the density of this particular snow — and the fact that it still hasn't had a chance to begin to melt.
"The snow has drifted in incredible amounts," explained structural engineer Tony Coviello, the principal at Summit Engineering in Portsmouth.
Those drifts can make it tough for homeowners to see how much snow has accumulated, and can create uneven snow loads on roofs, which can prove a problem, especially for older homes. "Only new buildings are really designed for drifting snow," Coviello added.
The snow that has been dumped on much of the region this month has been particularly dense snow, too, he added. He said that in Portsmouth, one foot of snow from the recent storms weighs as much as 20 pounds per square foot (PSF) — far heavier than typical snow, which can weigh as little as a third of that.
The snow isn't going away, either.
"We've had no melt-off," MEMA spokesman Peter Judge explained. "In a given year, you're going to have a couple of days. We haven't even had many sunny days, let alone warm days."
That stubborn, drifting, heavy snow poses a number of risks to roofs, a collapse being by far the most serious. But short of a collapse, heavy snow on a home's sloped roof can cause ice dams and leaks, and on a building with a flat roof, it can block heating units and cause their motors to burn out.
Here's what you need to know about the risk of a roof collapse, and what you can do about it.
TAKE STOCK OF YOUR ROOF
Homeowners should inspect their roofs from all sides for snow — not just the front, Coviello said, since the front could be clear while the back might be covered in snow drifts.
"If you look at your roof and one side looks clear, go around and check the other side. See if it's different over there," he advised.
Renters concerned about heavy snow on their roofs should ask their property managers if they've had anybody come to inspect the roof, and otherwise they should contact building inspectors, he said.
ROOF COLLAPSE WARNING SIGNS
Look for visual cues that your roof might be straining under the weight of the snow — like new cracks in walls or beams, sagging roof steel and bends in metal supports, MEMA advises.
New or severe roof leaks could be red flags, also, and be sure to listen for creaking, cracking or popping sounds or for doors that pop open on their own.
If your building's sprinkler heads are suddenly pushed down below the ceiling tiles or pipes along the ceiling appear bowed, those could signal the possibility of a collapse, too. So can doors or windows that are suddenly tough to open.
WHAT YOU SHOULD DO
"In general, what I tell my friends is that if you have over 2 feet of snow on your roof, remove it," Coviello advised, though he cautioned that his tip was a rule of thumb and that the amount of snow a roof can handle varies.
Use a snow rake to remove heavy snow from a pitched roof, starting from the edge and working your way in. Snow rakes are generally available from most hardware stores.
It's best to shave the snow down to just a few inches, instead of scraping it completely clean and risking damage to roof shingles. While you're at it, clear your gutters and drains, and remove large icicles hanging over doorways and walkways.
AVOIDING THE RISKS
Homeowners should remove snow from their sloped roofs from the safety of the ground — not only to avoid adding weight to an already strained roof, but also to avoid the risk of a potentially deadly fall.
In Massachusetts this week, one man died after he fell through a skylight while clearing a roof in Canton, and a teen was seriously injured in Westwood in a similar accident. Numerous other people have died or been hurt in other snow-related falls from roofs across the region this season.
"Don't go up there yourself," Coviello stressed. "Get a roof rake; hire a general contractor."
When you clear your roof, be sure to wear goggles and proper protective gear, and keep ladders and other tools away from utility wires so you don't electrocute yourself. Plastic snow rakes are preferable to metal — they carry less risk should they hit a utility line, and they're less likely to damage roofs.
Remember, too, that as you begin to clear your roof, you could risk triggering an avalanche, warned Michael Todd, a spokesman for the New Hampshire Department of Safety. Make sure your ladder placement is safe and you're wearing a harness, he said.
WHOM YOU SHOULD CONSULT
"If you have any doubts about the safety of your roof or of your house, you should get an engineer in," Todd advises. And if you think your roof may be about to collapse, leave the building and contact your local building inspector and a professional engineer immediately, Coviello adds.
If you aren't in fear of an imminent collapse, you can also contact your local building or fire department with general questions about your roof, MEMA adds.
Boston residents can also contact the city's Inspectional Services Department with questions about snow removal at 617-635-5300, or call the mayor's 24-hour hotline at 617-635-4500.
Be discriminating if you're hiring a roofing contractor to repair your roof. Massachusetts residents should beware of roofing scams and look to hire licensed contractors with local references, roofing credentials, insurance and written manufacturer and labor warranties, officials say, while New Hampshire residents should insist on recent references and be sure contractors are insured, Coviello and Todd say.
WHAT COMES NEXT
For homeowners, the need for vigilance doesn't end once the snow has been removed. After clearing the snow off the roof, Coviello advises homeowners to check their attics for cracks or broken rafters and, if necessary, to hire somebody to fix them or reinforce the roof.
Barring that, he said, a home's roof might be in the clear.
"If you think you've escaped any problems and you've removed the snow, then count your blessings — and let's hope spring comes soon."