Ice dams
Conditions are perfect for growing icicles on your house.
They generally follow the development of ice dams in the gutters. And they can impede the flow of melting snow, sending water back into your attic or walls.
Ice dams generally occur when snow piles up on the roof. Warmth from inside the house melts the snow next to the roof, and the snow above acts as insulation. Water flows toward the gutter, where it is no longer insulated, and freezes, clogging the gutter with ice.
Doing much about them in this weather is difficult and dangerous. But here are a few options:
- Poke a hole in the ceiling wherever a wet spot develops. If you don't do that, the water pooling overhead will spread across the ceiling and damage a wider area. You can use a large nail or screwdriver to make the hole. Have a bucket ready.
- Clean snow off the roof. If you have a low roof and can reach the snow pack with a long-handled rake, it's worth considering. Take care, however, because rakes can damage roofing materials.
- Chisel a channel in the dam to allow water behind it to run away from the house. Take care to set your ladder on solid ground.
- Another way to channel water away is to fill one leg of a pair of pantyhose with calcium chloride. Lay the hose on the roof so it crosses the ice dam and hangs over the gutter. It will melt a channel through the ice.
WEATHER BLOG
February's unrelenting snow prompted a concerned Darlene Kura to recruit her son and two of his friends last week to remove the 8 to 9 inches of snow that covered the flat roof of her Clintonville home.
Kura has lived on W. Henderson Road in a former doctor's office and home for 10 years and had never shoveled her roof.
"We were really concerned about the weight," Kura said. Her house was built in 1952, and the age was her biggest concern, along with a 3-year-old roof that bows in places.
She feared a cave-in.
And now she has more snow to deal with after today's storm. She said she'll likely be recruiting her son and his friends to tackle the roof again.
"We don't know when the next one is coming," she said.
But experts said local property-owners shouldn't panic, despite reports of roof collapses elsewhere, including an ice rink that caved in near Pittsburgh on Sunday.
"Most roofs should be OK," said Halil Sezen, an assistant professor of civil and environmental engineering at Ohio State University.
Roofs in Ohio should be able to accommodate up to 18 inches of snow, based on the 20-pounds-per-square-foot standard that the American Society of Civil Engineers set for the state, said Michael O'Rourke, a professor of civil engineering at Rensselaer Polytechnic Institute in Troy, N.Y.
The Ohio Building Code calls for roofs to aupport 20 to 25 pounds per square foot, said Stephen Metz, a principal in Shelley Metz Baumann Hawk, a Columbus structural engineering firm.
But most roofs should be able to handle up to 32 pounds per square foot, which is about 2 feet of snow, said O'Rourke, who heads a committee on snow and rain loads for the American Society of Civil Engineers.
"If it gets to be 32, it wouldn't be unusual for some roofs to have some problems," he said.
Metz, however, reminded residents that central Ohio roofs have already sustained big snows, including the March 2008 snowstorm that brought 20.5 inches to the area.
Doug Perry, president of Allied Roofing in Columbus, said he wouldn't be alarmed until the snow reached a depth of 4 feet on roofs.
Perry said he's received no calls yet for bowing or collapsed roofs.
Still, homeowners and business owners should keep an eye out for sagging roofs, Metz said.
O'Rourke said vulnerable structures include carports, poorly engineered sheds and lightweight roofs.
Heavy snow buildup likely contributed to the collapse of an ice rink southeast of Pittsburgh during a youth hockey tournament on Sunday. Players, employees and spectators were hurried out when a worker heard a crack in the roof. Everyone escaped from the building, which was constructed in 1965.
A gym at Blacksburg High School in Virginia collapsed on Saturday, and a Sykesville, Md., fire station burned after the roof there collapsed under heavy snow on Thursday.
In addition, a section of roof and a wall at the Smithsonian Institution's Museum Support Center in Maryland collapsed last week.
Trees and other plants are taking a beating as well.
There's no magic weight as to how much snow can take down a tree or its branches, said Gary Gao, an associate professor with Ohio State extension in Delaware County.
Evergreen trees with shallow roots could tip over, not only because of the weight of the tree but also because of Ohio's clay soil.
Information from the Associated Press was included in this story.
