Snow blamed for Atlantic roof collapses
Heavy snow is being blamed for the collapse of a number of roofs this winter across Atlantic Canada, and a spokeswoman for the insurance industry says the problem may get worse.
"We are seeing an increase this year," said Marlene Landry of the Insurance Bureau of Canada. "From what I'm hearing from my members, the worst might be yet to come in some areas with the heavy snow load."
Snow was blamed for the collapse of the community centre in Notre-Dame, N.B., last month as well as the partial roof collapse at a building for adult literacy and children's programs in Moncton.
In Nova Scotia, there was a partial roof collapse after several days of snowfall at the George D. Lewis school in Louisbourg. No one was injured and the school was evacuated.
"We're seeing it all over," Landry said. "It's not just one particular area that we're seeing an increase in claims."
Check on insurance coverage
Landry said most insurance policies cover damage caused by such accumulations of snow, but it's best to check with your agent.
The Canadian Building Code was strengthened in 2005 to consider greater snow loads on roofs.
"In the 2005 edition…we said they should be designing for a one-in-50-year snow load," said Mike Bartlett, an engineering professor at the University of Western Ontario in London.
Still, Bartlett said that might not be enough to stay ahead of extreme weather caused by climate change.
"One of the challenges as an engineer is that the climate change models haven't developed enough to be able to take the historic data that we have…and recognize how to adjust those data to account for the extra effects of climate change."
Bartlett said even if buildings are constructed to the most recent standards, they can still fail under heavy snow if they haven't been properly maintained.
Minneapolis Metrodome roof gave way
Snow was also blamed for collapsed roofs across other parts of Canada and in the United States, most notably the collapse of the Metrodome roof in Minneapolis on Dec. 13. TV cameras captured the scene as the roof gave way and snow poured onto the field.
"The collapse that occurred in Minneapolis at the Metrodome almost certainly occurred because the snow wasn't uniform or evenly distributed across the whole surface of the roof," Bartlett said.
"Due to local wind conditions it had concentrated itself in a big pile near the middle and large roofs like arena roofs are not very effective with dealing with concentrated loads like that."
He warned that homeowners who clear snow from their roofs must be careful not to create the same kind of situation. Bartlett said if people only remove the snow from part of a roof, they might actually be increasing the stresses on the rest of the span.
Meanwhile, Landry said insurance policies don't require homeowners to clear their roofs.
"If they can get up on the roof and remove some of that snow load that's there safely, then to do it is fine," she said. "But we don't want people out there doing unsafe things and with some of the conditions we're seeing right now, we're talking unsafe."