‘Potential nightmare situation’: What to do about ice dams when days get warmer

With nowhere to go, the water backs up and could potentially leak into homes

A seemingly endless stretch of snow and cold will finally let up with a slight warm-up in next week’s forecast.

While the Chicago area could enjoy periods of sunshine and above-freezing temperatures, the warming trend is little comfort to Michael Prate or anyone else who has to contend with the threat of another wintry mess: ice dams on roofs.

“We could have a potential nightmare situation developing,” says Prate, who’s been in the roofing business for nearly 50 years.

Ice dams form as snow begins to melt with the escaping heat of the house’s attic, runs down the roof and refreezes at the non-heated edges, jamming up gutters. With nowhere to go, the water backs up and could potentially leak into homes.

“Basically, the bigger the overhang, the more of a possibility that you’re going to have problems with ice dams,” said Ted McLaughlin, the founder of Ace Roofing Services in St. Charles.

February’s winter storms left layers and layers of snow blanketing rooftops on top of a coating of ice from an earlier system. The layer closest to the roof melts first, said Prate, a contractor with Prate Roofing in Wauconda.

“Now with the ice that was on most of these roofs, as the water melts, it’s hard for it to even get down to the gutter,” Prate said. “It’s got to get through all the ice that’s even on the roof above the gutter.”

Under Illinois code, residential roofs replaced in the last 25 years or so should have an ice and water shield, an-asphalt based product, to prevent leaking, Prate said.

“What that does is you cannot stop the ice dam from happening, but the ice and water shield will protect it from coming into the house,” he said.

But using one winter survival tool -- roof rakes -- wouldn’t hurt.

“It will still help alleviate that big backup, and there’s always the possibility of whoever the contractor was that did the ice shield might not have done it properly,” Prate said.

Homeowners standing on the ground can use a rake to clear snow -- ideally, 6, 10, 12 feet up the slope of the roof from the gutters -- to help ensure they won’t have any interior damage as the snow melts.

“The dams will be huge, and that’s where if people can do it themselves, rake some of the snow off, that’ll keep those dams from getting larger, too large,” Prate said. “It’ll help if they can do that or get a professional to do that because once it gets above freezing, it’s going to be a nightmare.”

Prate has a few words of caution. Do not start chopping at the ice dam with a shovel, a hammer or an ax. You’ll end up doing more “damage than good” to the roof itself, Prate said.

Be careful not to scrape away roofing materials. You don’t have to get right down to the shingles.

“A few inches isn’t going to hurt it at all anyway, so you just want to get the bulk of it off,” Prate said Tuesday. “And we’re out now because people have a lot of drifting, and they’re worried about the weight of the snow.”

If you’re not in a position to use a rake, call professionals. It also goes without saying: Don’t climb onto the roof to clear snow. Roof rakes can extend some 16 feet.

“You’ve got to be real careful in this kind of weather with ladders and going up on ladders. I don’t advise for the general public to do that,” McLaughlin said. “People get hurt on ladders really easily.”

Homeowners also can try placing nylon stockings filled with calcium chloride perpendicular to the gutter to cut channels in the ice -- just like making a hole in a dam -- so at least the water can run down and over it.

Home improvement stores also offer what Prate calls “salt pucks,” about the size of a hockey puck, to help melt some of the ice and create channels where the water buildup has a place to drain.

If you’ve got access to a heated faucet and a hose, you could turn on the hot water to make the same openings in the dam along the gutter edge, Prate said.

What causes ice dams? Improper ventilation or poor insulation causing heat loss through the roof can be culprits.

“Whether it’s ridge vents or typical square vents that are on roofs, if they don’t have enough, and there is any condensation, you should find a local contractor that will add ventilation,” Prate said, “or at least come out and check the amount that you have and see if it is OK.”