Government officials in Anchorage have taken the unprecedented step of warning more than 1,000 commercial property owners that their roofs could be at risk of collapse because of this year’s record-breaking snow loads.
The action came as a second roof in the city collapsed this week, at a building off the Old Seward Highway that was among those flagged to receive the warning.
In the letter, the city told building owners that if their roofs are determined to be at risk — or even if they aren’t sure — “we recommend that no one occupy the space until the snow is removed from the roof.” A municipal building official said a future step could be determining how the roofs should be retrofitted to strengthen them.
So far this winter, at least six roofs have partially collapsed following the heavy snow, and at least 16 failed last winter. Last February, a woman died in a collapse. Nobody has been hurt or killed in this winter’s collapses, and no residential collapses have been reported.
More than 8 feet of snow has fallen in the city this season, with more all but certain to arrive before the spring melt.
The warning letters were sent late Tuesday from the Development Services Department to approximately 1,070 people with properties identified as possibly susceptible to roof failure.
“We’re thinking we have hundreds of these buildings out there,” said Anchorage acting building official Ross Noffsinger. “If they haven’t removed the snow yet ... we’re feeling that the potential for failure is high enough that we basically we need to make direct contact with the building owners and ... request that they remove the snow and not occupy the space until the snow is removed.”
The letters include photos of the roof structures that are a concern, as well as photos of roof construction that are not considered a problem.
Last March, officials with the municipality identified the problematic design flaw common to most of the buildings that collapsed, Noffsinger said. The failures primarily occurred in structures supported by wooden truss beams connected with metal gang nail plates built before 1990, particularly among flat-roofed commercial buildings with long truss spans.
The letter is expected to start arriving in property owners’ mailboxes before week’s end.
Anchorage has about 80,000 buildings, Noffsinger said, and the municipality compiled the list of buildings at risk through a combination of property records, pre-existing aerial surveys and images from Google Maps.
He declined to provide a list of the buildings and said there are no plans to publicize it. That’s due to concern about property theft if buildings are vacated until snow clearing can occur, he said.
The municipality has never taken the step of sending out letters to property owners to deal with the risk of roof collapse from snow load, he said.
Many of the roofs have collapsed at snow loads that are below the design standard, the city’s notice says.
“The roof construction of concern has failed multiple times even when supporting less than 25 pounds per square foot of snow,” the letter continues. “Additional time or snow could lead to failure.”
The snow load on uncleared roofs has likely grown to about 30-35 pounds per square foot, after 17 inches fell on Anchorage early this week, Noffsinger said. Anchorage code dating back to at least the 1960s requires that buildings support a minimum of 40 pounds per square foot of snow.
Two people who experienced damage because of collapsed roofs said they’re glad the municipality is taking increased steps to deal with the problem.
They suggested more could be done.
Anna Dugan said she and her husband were leasing storage space in a commercial condominium unit at 5401 Cordova St. when the roof collapsed earlier this month.
The roof collapsed onto the RV the couple was keeping inside the unit, she said.
She said building owners should take the issue seriously.
She suggested the city could consider taking additional steps so the public can feel safe entering one of the high-risk buildings. As one last-resort option, the city might consider publishing its list of businesses, she said.
FashionPact owner Brittani Clancey, whose downtown shop collapsed dramatically in March last year, said better notification to property owners is an important step.
She said her roof had been shoveled and didn’t hold much snow before it collapsed, so shoveling may not guarantee a roof’s safety.
She said it’s been a challenging year getting her business back on its feet. She successfully challenged her insurance company to get a fair payout, but it took 10 months and required her to hire multiple experts. She also took the costly step of opening a new store following the collapse.
“I’m grateful we didn’t die, but this process has been rough,” she said.
It seems like the collapses will keep happening as certain buildings age, unless something is done, she said.
“The best thing in my opinion is to figure out the cause,” and how the roofs can be retrofitted to survive Alaska winters, she said.
Noffsinger said there are no regulations requiring property owners to say, clear roofs of heavy snow loads. There aren’t any plans from his department to propose any at this point, he said.
“We’re really trying to thread the needle here, between public safety and being accurate and reasonable,” he said. “No one’s being blamed. We’ve just discovered this thing that needs to be addressed.”
He said now that the letters have been mailed, the next step for the municipality could be determining what must be done to retrofit the high-risk roofs.
“It seems a logical conclusion, with what we know now, that there will be a significant number of buildings that are going to require their trusses be strengthened,” he said.
Some trusses may need to be replaced altogether, he said.
He said it’s only good fortune that more people haven’t been hurt by the damaged roofs.
While no residential roofs have been reported as having collapsed this year, Noffsinger has said previously that with so much snow this year, homeowners and landlords should think about clearing their roofs at least once this winter.
It’s a case-by-case basis, he said on Wednesday.
Residential roofs typically span small areas compared to commercial building roofs, with more supporting walls, factors that help make them less prone to failure. The municipality has issued snow-clearing guidance for both commercial and residential buildings.
Determining when to clear a house can be complicated, Noffsinger said.
New construction homes built after 2000 should not be at risk of a damaged roof from heavy snow load, he said.
Older homes, such as those built in the 1940s or 1950s, should be cleared if the owner is concerned, he said.
Homes built around the 1980s, a period that saw many Anchorage houses built, are a mixed bag, he said.
The city had good building code requirements, but poor oversight then, he said.
“That’s really the homeowner’s call,” he said.