Darn those ice dams

The snow from recent storms had covered up the ventilation pipe on this home. Photos by Denise Coffey.

They are everywhere - those big icicles hanging from so many houses.  They may look beautiful, but they signal a nasty problem lurking underneath: ice dams.  Those ridges of ice that form at the edges of roofs may look like an exterior problem, but the culprit is insufficient insulation inside the attic.  When warm air from the house rises into the attic it heats up some parts of the roof and leaves other parts cold.  Warm air can make its way into the attic wherever chimneys, light fixtures and even attic doors exist.  
Even small air leaks can allow enough heat into the attic to cause trouble. When attic space warms up enough, it can melt the snow on the upper portion of the roof. The run-off pools on the cold section of roof where the ice dam has formed.  If enough water pools at the ice dam, it can back up and make its way through the roof tiles into a house. This water can damage ceilings and walls and leave sodden insulation in its wake.
The way to fix an ice dam is to properly ventilate and insulate your ceiling and attic. The best time to do this is in the summer. But when it’s late January and water is dripping in over the kitchen window, you have to have another option in mind.
According to the University of Minnesota’s Extension service, the safest method for getting rid of ice dams is to hire a contractor to steam it off the roof.  Minnesota’s average January temperature is 7.94 degrees Fahrenheit, so they should know a thing or two about dealing with ice dams. But if you can’t do that, and you must do something, these are some options.  Just be forewarned: doing any of them incorrectly could damage your roof.
1. Take a box fan into the attic and direct the flow at the underside of the roof where water is leaking.  Sometimes directing enough cold air at the leak will freeze and stop it.
2. Rake the snow off the edges of the roof with a long handled aluminum roof rake. Stand on solid ground. Do not get onto a slippery, icy roof. Get a rake with wheels (not all roof rakes have wheels) so you won’t damage the roof. Andy Wasielewski, a customer solution expert with Chace Building Supply in Woodstock urged caution.  “You’ve got to be careful,” he said.  “You don’t want to go down to the shingles.”
3. Hosing with tap water on a warm day can be effective in the short run, as long as you make sure you work upwards with the water.
“Lots of stores sell adapters,” Wasielewski said. “The thing you want to remember is to create the channel at the bottom of the ice dam.” You don’t want to add more water to the pool that’s already sitting behind an ice dam.
4. Fill the leg of a discarded pair of panty hose with calcium chloride ice melt. Lay the hose onto the roof so that it crosses an ice dam and overhangs the gutter. This will create a channel for water to flow off the roof. BE FOREWARNED: Calcium chloride and salt are corrosive and can shorten the lifespan of gutters, downspouts and flashing.  Runoff can also damage plants and grass.  
5. Heating cables can keep ice from forming, but requires installation, can damage shingles and will use a lot of energy.
6. You can chop the ice with a blunt tool, but this can lead to shingle and gutter damage if you aren’t careful.
“If you stay on top of the snow, if you clean your roof with the roof rake and stay on top of it, you’re all set,” Wasielewski said.  But even he admitted how hard it was to do just that.
Connecticut has seen three times its average snowfall amount in January, according to Shaun Tanner from www.weatherunderground.com  “We haven’t been used to this much activity. It’s been storm, storm, storm,” he said. Unfortunately, more snow and cold weather was on its way as of press time.