What Is An Ice Dam?
A ridge of ice that forms on the lowers areas and/or edges of a roof under certain wintertime conditions. An ice dam forms when the roof over the attic gets warm enough to melt the underside layer of snow on the roof. As the snow begins to melt on the higher parts of the roof, the melted snow will start to melt and flow down the roof but refreeze when it gets to the lower edges, forming an ice dam.
Damage Ice Dams Cause
When an ice dam gets big enough, the water running down the roof will have nowhere to go and will start pooling and finding its way under the shingles. This can lead to water damage in your home. If the ice dam becomes too heavy and falls off it can pull down your gutter and shingles with it.
Dealing With Existing Ice Dams
Homeowners need to be VERY cautious removing ice dams from their homes. Start but breaking it free in small chunks. Lightly tap with a blunt mallet to present puncturing shingles or gutters underneath the ice. Channels can be made in the ice that will allow the water behind the dam to flow through the dam and drain off the roof. This is only a temporary solution; however, these channels will refreeze, so you will have to monitor this until all the ice is gone. Clear out gutters and down spouts. Lastly, Melt troughs through the ice dam with calcium chloride ice melter.
Preventing Ice Dams
Scrape the snow from the roof whenever it falls, using a snow rake. This is not a safe or recommended method. You can avoid ice dams forming in the first place with proper insulation and proactive snow removal from the edges of your roof. The cure lies in sealing all points where warm air leaks from the living spaces immediately below the roof, insulate within the attic space, and properly vent the space between the insulation and roof sheathing.
The ice dam cure will also cure a significant loss of heat from your home. It’s a win-win situation.