Howling wind could lessen the chances for damaging ice damming, a rooftop phenomenon that is supposed to be statistically rare in Oklahoma but has been a feature of winter for several years in a row now.
Ice damming is when ice builds up along the edges of roofs and backs up under shingles and flashing. When it melts, it damages roofs and causes leaks, usually along walls. On-and-off-again melting is the worst.
“The good thing for roofs is that the snow is blowing. It most likely won't accumulate on your roof, unless it drifts there,” said Brad Neff, owner of Heartland Roofing in Bethany. “If your roof is such that it has walls that butt up to low-sloped areas or flat areas, it is possible that large amounts of snow will accumulate. On flat roofs this can create the potential for collapse.”
Drifting snow on roofs can create problems, however, if not removed, said Mark Lenzer, vice president of Metro Roofing and Reroofing America, two companies in Oklahoma City.
“The freeze-thaw cycle will cause ice dams to intensify, especially because the wind is not only causing snow drifts on roads, it is creating them on roofs too,” Lenzer said, noting that freezing and thawing and refreezing aren't the only causes of damming. “Homes that are not properly insulated and not properly ventilated — then the bottom layer of snow could melt, then refreeze causing an ice dam quickly, too.”
Neff said damming can sneak up on a homeowner because its effects occur after the worst of a storm has passed, Neff said.
“Ice damming can cause large amounts of interior water damage as the temperature warms and the ice and snow melts,” he wrote Tuesday on his blog at www.trustheartland.
Ice and water shields can be applied to roofs to prevent damming.
Stay off the roof
Both Lenzer and Neff stressed that no homeowner should climb onto a roof to remove snow or ice.
Neff had some other tips for dealing with rooftop snow:
Any roof suspected of leaking should be scrutinized by a pro, Lenzer said.
“For all leaks, call a qualified contractor to do a thorough inspection. Some leaks are very difficult to find, and years of experience will play into how well the contractor is able to determine where the leak originates and the proper solution for a leak- resistant, permanent fix,” he said.
Can ice damming still be considered rare in Oklahoma? Maybe not, Lenzer said.
“Looking back over our 30-plus years of experience, it usually happens once every few years, but with the weather pattern over the last four years it isn't rare anymore,” he said. Lenzer said part of the problem is south versus north thinking.
“The problem in Oklahoma is that building codes do not specify for ice and water shield to be properly installed under the shingles,” he said. “Homeowners should seriously consider paying extra for ice and water shield to be installed when their home is reroofed. In the northern states this is required by code for new construction, and when houses are reroofed. Consequently, here in Oklahoma it becomes a problem.”
How to make a snow rake, from The Weather Channel: