Ice Dams on the Roof
An ice dam is a ridge of ice that forms on the edge of your roof and prevents the melting snow and ice from draining off into the gutters. The water then begins to go backwards up beneath your shingles and then into your house.
You may not be able to prevent an ice dam from occurring, but you can prevent the damage that they cause by taking a few simple steps.
Those icicles that hang off of the roof and look so pretty, really are not desirable.
How do ice dams form?
First off it snows and you have a nice layer thick layer of snow covering your roof.
Then either the sun, or loss of heat from your home, cause the snow on your roof to melt. Water begins to flow under the snow on its way down the roof. If the air temperature is below freezing, the temperature of the roof deck, gutters, valley flashing and downspouts very possibly will be below freezing. When the melting water hits these cold surfaces it begins to rapidly freeze and the gutters and downspouts are choked with ice.
The ice continues to build up at the edge of the roof or gutter. If the water is melting at a faster rate than it can freeze, it begins to back up underneath the roofing materials. This is when problems arise. Serious problems.
SO what can you do?
If it is possible, shovel the snow off of the roof. Without snow on the roof there can be no ice dam formation. This is especially true in problem areas.
The second thing is to minimize heat loss through the roof. Increase the ceiling/roof insulation, at least an R value of 38, to cut down on heat loss.
