An ice dam forms on the roof of an Airport Heights home in Anchorage in 2023.
© Valerie Kern/Alaska Public MediaAn ice dam forms on the roof of an Airport Heights home in Anchorage in 2023.
Anchorage residents are wondering if they should shovel their roofs, with record-setting snow from November and December still sitting atop many homes in Alaska's largest city.

According to a city official and at least one private building inspector, that depends. But, they say, it's probably not a bad idea.

Current estimates put the snow load at a level lower than what most residential buildings in the city are built to withstand. But with several winter months still to come, there's the potential for more snow, and ice-damming on roofs is an already present concern.

"If it keeps snowing and the weight keeps accumulating, eventually we're going to hit that point where we're concerned about the weight," said Ross Noffsinger, Anchorage's Acting Building Official. "And at that point, we're going to issue a notice to the community that we're concerned about the weight."

Noffsinger estimates that the average current snow load on a home in Anchorage is about 20 to 25 pounds per square foot. Anchorage homes are typically built to handle 40 pounds per square foot. Noffsinger said the city tends to see its heaviest snow loads in March and April, before warmer spring weather melts it away.

Right now, Noffsinger said, the city is focused on commercial buildings, especially those with flat roofs built on parallel wood chord trusses. He advises that owners of those buildings should start removing snow.

"It seems that we see these roofs failing when the snow gets up to around 20 to 25 pounds per square foot, which is where we're at right now, and which is roughly likely where the Spenard Builders Supply building was when it collapsed," Noffsinger said.

The construction supply company's former truss plant on West 46th Avenue suffered a large-scale roof collapse in December, with no reported injuries. However, in Feb. 2023, a flat-roofed CrossFit gym collapsed, killing a woman. Ice accumulation was suspected to have caused that collapse.

Residents removing snow from commercial buildings should not make piles on the roofs, in order to avoid overloading specific sections of roof, Noffsinger said. For people shoveling snow off of their homes, he said they should make sure snow doesn't pile up against the house or on top of gas or electric meters.

But the weight of the snow is not the only reason an Anchorage resident might want to shovel their roof.

Jon Schultz, a building inspector with Accurate Inspection Services, said he advises people to start shoveling their roofs now to avoid the build up of ice dams. That's when snow melts on a roof, water trickles toward the eaves and a wall of ice forms, trapping more snowmelt in a way that can cause roofs to leak and other damage.

"(It's) a big pile of ice along the outside edge of the roof," Schultz said. "So the more snow you have, the more it melts. That creates fuel for the ice dam. It also heats up the attic, which makes the snow melt quicker."

Noffsinger, with the city, said at this point in the season, residents should consider how to safely remove snow from their roofs, as well as the price of hiring a private contractor.

"So if somebody has the means to safely remove the snow from their own roof, it probably would not be a bad idea to start doing so, given how early it is in the winter, and given the amount of snow that's potentially on the roof," he said.

As of Monday, the city has officially seen just over 87 inches of snow this winter, more than it receives on average for the whole season. Anchorage's all-time seasonal snowfall record was 134.5 inches, set in the winter of 2011-2012.