With the fluctuations in temperatures this winter, we are seeing a lot of ice build up and icicles on roofs in many neighbourhoods. Ice build-ups on roofs are a safety hazard but they can also be an indication of a problem with your insulation or roof drainage.
A large build-up of ice at the edge of a roof is called an ice dam. It's called a dam because once it forms it also changes the way the roof drains, presenting an obstacle for free moving water to exit the roof.
Ice is not only a concern for walkways or traffic routes near roof lines, it can also damage your roof, gutters and downspouts.
Ice dams are caused when the underside layer of snow on the roof begins to melt, causing meltwater to migrate to eave of the roof and refreeze.
Under normal conditions, for example if the melting is caused by heat from the sun, the eave will also be warmed by sun and the water will drain and not freeze.
When the melting is caused by excessive heat loss from the attic, then the eave area, which extends out from the house, will be cold and will cause the water to freeze and build up over time, creating an ice dam. There is only one prevention for ice dams and that is to have better insulation, sealing and venting from the attic and eaves.
If an ice dam gets big enough it will cause the melt water to back up and seep under the shingles. Often the process continues, and the water drips into the insulation and down into the ceilings and exterior walls. Water damage will ruin sheetrock and paint on walls. Large ice dams can also break free and pull off roof shingles and even the gutters, potentially falling on cars, shrubs, people.
Ice dams are a symptom of a problem with your building envelope.
If you've had an issue with ice this winter, give us a call to talk about improving your attic insulation. With decades of experience in Simcoe County we are familiar with the local weather demands and offer a range of insulation options, including premium products that are exceptional at energy conservation.