Solutions to the Damn Ice Dams

By Doug Hanna

We're having quite a winter here in the Boston area. Here at S+H Construction, we are getting dozens and dozens of calls from unfortunate people who have water leaking into their homes from ice dams. Icicles can be beautiful, but they are an indication that some ice damming is taking place. 

Solutions to the Damn Ice Dams

Ice dams, which form at the lower edges, or eaves, of pitched roofs, are formed by the action of snow melting where it meets the roof surface. Poorly insulated roofs allow heat from the inside of the house to warm the roof surface. This melts the snow, which then runs down the roof towards the eaves and gutters. On most houses, the eaves and gutters overhang the plane of the house. This means that the eaves are cold in comparison to the rest of the roof. When the water running down under the snow meets the cold overhand at the eaves, it freezes. The action of this process over a number of days/weeks builds up the ice into a large hump at the gutters and edges of the roof, while the snow continues to melt higher up on the roof. Now the water has nowhere to go, so it backs up under the roof shingles or any other path of least resistance. This can mean that it may eventually find its way into your soffits, exterior walls, or roof cavity, and express itself inside the house with leaking through light fixtures, window heads, and ceilings, etc. 

Short term solutions begin with clearing the roof of snow. If there is no snow to melt, the water will eventually stop. Large chunks of ice and icicles should be removed, but be careful and tell the people doing the job to avoid banging away at the edge of the roof and gutter. This can cause more damage than the leaks! Salt (Sodium Chloride) can be applied to big slugs of ice in the gutters to start breaking them up. Another  thing you can try is to keep the heat down on the upper floor as low as possible ( but not so low as to risk pipes freezing ). The whole problem here is that the roof surface is too warm, from the heat inside the home. 

The long term solution to ice dams is to create a "cold" roof. There are two ways to accomplish this:

  1. Installing modern foam insulation in the cavity of the roof (area between the roof rafters)
  2. Applying several inches of rigid insulation on the outside of the roof sheathing and under the roof shingles. 

This second option must be done in conjunction with replacing of the roof. For people with finished spaces under the angle of the roof (finished attics), putting modern insulation in place can be more challenging, but it can be done. Modern insulation and creation of a cold roof, where the snow melts consistently, is the key to prevention of ice dams. 

Please don't attempt to clean roofs yourself in these conditions. If the damage from leaking is extensive, call your insurance company and get approval for a disaster clean-up company to come in and do moisture removal / clean-up. For long term solutions and more ideas about prevention of ice dams, please contact S+H Construction at (617) 876-8286 or