Ice Dams: Causes and Cures

Ice Dams: Causes and Cures

To say that that the Winter of 2014 has been rough in the northeastern US is to put it mildly. In Philadelphia, we've already had 58 inches of snow and could challenge the 2009-2010 record of 78 inches. Add frigid temperatures to the mix and you have the key ingredients for ice dams which can cause home damage, making them less saleable as well as less inhabitable.

But what is an ice dam? It's the buildup of ice at the base of the roofline (see photos), and frequently on top of gutters, that can impede the flow of melting water from the roof. This water can then seep under shingles and cause various kinds of damage to the interior and exterior of a home including: mold and mildew, wood rot, water stains and insulation damage. The weight of such dams can cause gutters to bend or even detach completely from the house.

Follow the link below for a graphic depiction of how ice dams form.

Ice Dam Graphic

Alright, I've got ice dams. Now what do I do? There are professionals that remove ice dams with a steamer--not a power washer which can damage the roof. For the homeowner who wants to do it himself, there are unfortunately no easy solutions. Most, if not all, involve putting up a ladder in the middle of Winter to get close to the dam. Perhaps the best of the admittedly imperfect solutions is to use a pick and hammer to chip away enough ice to allow a channel for backed up water to drain. You have to be careful not to damage the roof or gutter or, more importantly, yourself. Follow the link below for an informative--sometimes hilarious--account of 7 different methods of ice dam removal.

Ice Dam Removal

Given the difficulty or expense of removing ice dams, the next logical question is how can they be prevented. The short answers are:

Improve roof ventilation and prevent leakage of warm air into the attic

Install heat cables on the roof and in the gutters

Use a roof rake such as those sold at Home Depot to remove snow before ice dams have the chance to form.

The first method is the preferred one. It costs less than heat cables and has other benefits. Method 3 relies on one being on-hand and able to remove the snow and may not be practical for roof lines on the second floor and above. Follow the link below for a more detailed account of ice dam prevention methods.