Rooftop snow loadings promise damage from ice dams

The threat of roof-damaging ice dams is high this week as temperatures rise well above freezing for the first time in weeks.

Snow depths on roofs in the area vary from none on the steepest roofs, to a foot or more on some low-pitched residential roofs. Homeowners with steeply pitched roofs have little to worry about, according to Jeremy Bleeker of Eastern Iowa Construction & Roofing in Marion. He says low-pitched roofs are where the ice dams tend to cause leaks, usually early in the afternoon when temperatures climb into the thirties.

Bleeker says the best prevention is removing snow from the lowest two or three feet of the roof with a snow rake from the ground. Removing the overlying snow allows the air and sun to reach the ice. In relatively short order, Bleeker says, the ice will go away, allowing melt-off to flow freely.

Bleeker also recommends installing heat tape in the rain gutters of the roof, before snow and ice accumulate, or installing a type of heated guttering that melts ice.

Pounding on ice dams with hammers or axes to break them up can damage shingles and lead to even more damage, Bleeker says.

Buying a snow rake this time of year isn't easy. They range in price from about $30 to $60, if you can find them.

Lenoch & Cilek Ace Hardware in Coralville usually carries snow rakes, electric heat tape, and ice melting pellets called Roof Melt to fight ice dams. All were out of stock Tuesday, Manager Ray Adams said, but more were expected to arrive on Friday.

Vernon Village True Value in Cedar Rapids was down to its last two snow rakes and out of heat tape Tuesday, said employee Joe Dolinaj. The store was reordering.

Roofing contractors know best how to remove the ice dams that are already causing leaks without damaging the roof. They often use torches to melt the dams.

Curt Black of Iowa City Roofing recommends that Iowans learn from Minnesotans and Canadians, who routinely rake snow off their lower roof before it gets hard. Black says he routinely rejects ice dam removal requests because the work is so dangerous, and the damage, in most cases, has already occurred.