Roofing contractors enjoying the snow

A bedding store’s warehouse on the West Plains, a fire station in Valleyford and an apartment complex carport in Spokane Valley are among the structures that have collapsed under the weight of this season’s snowfall.

All had flat roofs, which are the most vulnerable, said Brian Owens, owner of Owens Roofing & Supply in Spokane. .

The snow measured from 1 to 2½ feet on most of the structures that buckled. Peaked roofs can hold up to 4 feet of snow, experts say.

Like other roofing contractors, Owens has been busy since the snow began to pile up. By noon Thursday he’d inspected seven roofs in Spokane’s South Hill area.

“A standard (peaked) roof is designed for a 40-pound snow load per square foot – the industry standard for truss design,” Owens said. “One of the most important things is to make sure the roof vents are cleared so they can breathe. That helps because if the vents are covered up, no matter how good the insulation, the inside heats up and melts the snow prematurely, which creates ice dams and backs up the snow on the roof.”

One exception to the peaked roofs are those made with asphalt, granular shingles, said Lane Pearson, who works in the maintenance repair department for Cobra Roofing and Metal Wall Systems. “The snow won’t slide off. I’d become concerned at about 2 feet.”

The age of a home also is a factor, Owens said. Those built after the 1960s usually are pretty sound.

And generally, there’s a confidence that roofs are built for the conditions in this area, Pearson said.

Despite that assurance, many people have called roofing companies for inspections. Pearson said the ones they’ve shoveled off have been about 4 feet deep and primarily in Idaho.

In Sandpoint, deep, heavy snow triggered a response from 46 members of the Idaho National Guard, who used snowblowers and shovels to clear school roofs. When a 90-year-old building’s roof caved in at Priest River, volunteer firefighters spent a day shoveling off city buildings.

With news of collapses, home and business owners have called for advice, according to roofing and structural engineering companies. “It’s been pretty busy,” Pearson said. “It’s a matter of do you want to roll the dice.”