Dealing with Ice Dams

The recent heavy snows followed by a long spell of cold weather mean that ice dams will soon develop across the metro. Here is what you need to know about ice dams and how to prevent their occurrence.

Ice dams occur when excessive heat builds up inside the attic, causing the snow on the roof to melt from underneath. When that water reaches the edge of the roof, it will freeze if the outside temperature is cold enough. If there is enough snow on the roof and the temperatures are cold enough, this melting and freezing process will continue around the clock, day after day, resulting in some impressive ice dams. When the weather turns warm, the rate at which the snow melts accelerates, creating a pond of water backed up behind the ice dam. Shingled roofs are designed to shed water but they are not waterproof. The ponding water can then begin leaking into the outside wall, and through the ceiling along the outside wall.

Some people believe that the way to address an ice dam is to remove the snow and ice from the roofs before an ice dam can form. There are several problems with this. First, removing the snow and ice is simply treating the symptoms of an ice dam (water on the roof), and not treating the disease (warm attics). When you consider the cost to remove snow and ice from a single roof averages $300 to $400, an association of 100 units is now looking at a total cost of $30,000 to $40,000 to address every roof. For most associations, this is a huge unbudgeted expense. This type of work also shortens the life of the roof system by physically disturbing it and treats the symptoms but does not cure the disease.

Ice dams can be prevented by controlling heat loss from your home. Improving your attic’s insulation is the most effective strategy for combating ice dams, particularly in older homes. Generally, the higher the R-value of the insulation the better. An ice dam problem also can be the direct result of attic bypasses – the openings into attics around such things as recessed ceiling lights, exhaust fans, plumbing pipes, chimneys and flues, electrical wiring and attic access covers, all of which need to be thoroughly sealed in order to prevent the warm air from rising into any area just below the roof. In some cases, the soffit vents may be plugged from existing insulation. The objective is to make the roof as uniformly close to the outdoor temperature as possible.

So who is responsible to correct a warm attic? In many cases, unless you live in a condominium, each owner is responsible for sealing attic bypasses, ensuring that ventilation chutes are open, and adding insulation if needed. To be certain, refer to your association’s maintenance service policy or check with your HOA management company. Although your association may be responsible for maintaining roofs, remember the problem is not the roofs, but rather the warm attics. Therefore, many associations will remove the ice and snow but charge the costs back to the owner. Also note that the cost to repair interior damages is, and always has been, an owner cost, up to the deductible on the association’s master policy.

If you had an ice dam problem in the past and have not taken the steps to correct it, you need to call an insulation contractor now before the next severe ice dam strikes. The cost to correct your warm attic may well be less than the cost to remove ice and snow and repair the interior water damages. Plus, you will lower your heating bills, which will save you money every winter. For more information on ice dams visit  https://extension.umn.edu/protecting-home-rain-and-ice/dealing-and-preventing-ice-dams or read “Preventing and Removing Ice Dams: A Comprehensive Guide for Homeowners.”

(Photo credit: J. Triepke via Flickr cc)