Heavy snow leads to roof collapse

A roughly 40 by 100-foot portion of the roof on a hog confinement barn owned by Jeff and Deb Brockberg, of rural Trosky, collapsed early in the morning on Saturday, Jan. 21.

“We’re going to have to replace about 50 percent of the barn,” Brockberg said.

There were 1,000 pigs in the barn that were ready for market when the roof collapsed. Fortunately, only one was injured. The animals were moved to another one of the Brockbergs’ barns about a half-mile away.

Brockberg said the problem started in early January when the Trosky area received around 20 inches of snow.
“It loaded up the roofs on a lot of these confinement barns, especially those that are located somewhat behind windbreaks,” he said. “Ours is located behind a farm windbreak. Snow kind of gets over the trees and lands on the back side of the south-facing roofs.”

Typically, Brockberg said, workers go up on the roof and shovel snow off when necessary, using ropes to prevent them from slipping off. In this case, rain saturated the snow, which made it even heavier, and it then solidified, which made it harder to get off the roof, Brockberg said.

Brockberg said he’d spoken to contractors and others who told him there had been several other confinement barns and machine sheds in the area south of U.S. Highway 14 that had collapsed or been damaged due to heavy snow loads. He said some of the issues that make the buildings more susceptible are the larger spans of the roofs and the screws that hold that metal down, but also makes it harder for ice to slide off.

Minnesota Pork Producers Association CEO Jill Resler said the organization was aware of some isolated structural collapses that have occurred this winter.

A roughly 40-foot by 100-foot section of the roof of this barn owned by Jeff and Deb Brockberg, of rural Trosky, collapsed due to heavy snow load on Saturday, Jan. 21. Such buildings are susceptible to collapse when there is heavy snow due to the large surface area of the roofs. K. Kuphal

“Structural collapses typically occur when areas of the state receive heavy snowfalls over a condensed period, especially when the snow accumulation is wet, heavy snow,” she said. “Generally, the age of the building is a contributing factor when a structural collapse occurs; older buildings are at greater risk. Newly designed barns are engineered to reduce snow piling on the roofs allowing for the wind to naturally clear much of the snow.”

Jeremy Whipple, owner of Pipestone Building Materials, said he’d heard of a few buildings such as confinement barns and pole sheds that had roof collapses in the area this year. He said the large roofs are designed to handle only so much weight and that heavy snow loads take a toll on the rafters over the course of years.

To prevent structural collapses, Resler said farmers should remove the snow load on barn roofs as much as possible and as safely as possible. That can be done with shovels and telehandlers. Whipple said there are contractors producers can hire to get snow off their roofs.

Heavy snow loads on the roof are not only a concern for agricultural buildings. Pipestone County Medical Center (PCMC) Plant Operations Manager Pete Swanson told the PCMC Board of Directors during their Jan. 24 meeting that he brought in a ground thaw machine to melt snow off the roof. Typically used to thaw ground, as the name suggests, the machine has a boiler that heats up antifreeze and runs it through hoses to heat an area.

“With that January 2 and 3 snowfall, we had a lot of snow on our roof that’s basically in the area of the MRI and to the north,” Swanson said. “We’ve got an area that we can’t get the snow out of there, so we did rent a snow melt machine. We got out about 900 feet of hose and put it on all the snowbanks and everything to help melt them away. We covered them up with insulated blankets that they use to insulate concrete and tried to melt as much snow as we could away.”

Swanson said they try to place the hoses by the drains in the roof so that as the snow melted it can drain off the roof.
“It was a challenge to find everything because there was four feet of snow,” Swanson said. “It takes a lot of shoveling to get the snow out of there, but we don’t want to be calling the insurance company and saying we had a roof collapse. We want to do as much as we can ahead of time to take care of the issue.”

He said PCMC has taken similar measures in the past due to heavy snow loads and has even used snow blowers on the roof before.