Ice Dam Prevention
By James Lunders, Agent
As winter progresses through cycles of freezing and thawing, many homeowners experience ice buildup and roof damage. An ice dam is an accumulation of ice at the lower edge of a sloped roof, usually at the gutter. When interior heat melts the snow on the roof, the water runs down and refreezes at the roof’s edge, where temperatures are much cooler. Eventually, the ice builds up and blocks water from draining off of the roof. This, in turn, forces the water under the roof covering and into the attic or down the inside walls of the house. Once an ice dam forms, the potential damage can be serious. Take these steps now to avoid trouble later:
- Ensure that gutters are clear of leaves and debris.
- Keep the attic well ventilated. The colder the attic, the less melting and refreezing on the roof.
- Keep the attic floor well insulated to minimize the amount of heat rising through the attic from within the house.
This three-step approach decreases the likelihood that ice dams will form or, at least, reduces their size. As an extra precaution against roof leaks in case ice dams do form, consider installing a water-repellent membrane under the roof covering. Talk with your local building official about minimum code requirements for ice dam protection.
In the event that an ice dam has already formed, there are several steps that may be taken to reduce its ill effects. Using a roof rake and push broom, remove the snow by carefully pulling it down the slope of the roof line. Never pull snow across the roof as it may break off the shingles and cause further damage. In an emergency situation where water is flowing into the house structure, making channels through the ice dam will allow water behind the dam to escape. Hosing with tap water on a warm day will accomplish this. However, these channels will become ineffective within days and should only be viewed as a temporary solution.