Ice Damming

1/23/2019 (Permalink)

The first major snow of the season has fallen.  Soon you may see icicles hanging from the gutters of homes.  But did you know that those icicles are most often the result of ice damming and can lead to water damage and eventually mold in your home?!

An ice dam is a ridge of ice that forms at the edge of a roof and prevents melting snow (water) from draining off the roof. As snow melts from your roof, either by the heat of the sun, or by heat escaping from your home, it tends to refreeze at the edges and other juncture points of your roof. The refreezing of water has a damming effect creating an even bigger ice dam behind it. Continuous feeding of the ice dam by melting and refreezing snow melt can cause significant damage. As the water seeps under shingles it refreezes expanding and creating an even bigger gap for future drainage to fill and further the cycle. Your shingles are being raised and eventually the water that backs up behind the dam, and underneath the shingles, can leak into your home and cause damage to walls, ceilings, insulation, and create a perfect environment for mold growth.

To prevent ice dams, it’s important to clean your gutters before winter so that winter’s melting snow and rain can properly drain off your roof. 

Additionally, improper insulation and improper attic ventilation can contribute to ice damming by allowing warm air from inside your home to escape into the attic. It seems counter-intuitive, but the basic ventilation principal for your attic is to keep it as cool as possible during the cold season.  If you look at your roof several days after a snow and you see an even distribution covering your roof, that’s a good sign that your attic is properly insulated and ventilated.  If on the other hand, you see sections where snow has melted, that suggests an area in the attic where warm air is present due to either improper insulation or improper ventilation.  These problems should be addressed as soon as the weather allows.    

Some homeowners also find it useful to use a roof rake during the winter months.  A roof rake is not your average garden rake.  It is a specialty item used to remove snow from the 4-6 feet of roof above your gutter, while standing safely on the ground, so that melting snow can properly flow off of your roof versus forming an ice dam.  Roof rakes can be found in season at most hardware and home improvement stores.  If you choose to use a roof rake, it’s important to follow all suggested safety precautions and suggestions for use.  Additionally, it’s important to know the condition of your roof and shingles.  Older roofs, or roofs in poor shape, can easily be damaged by roof rakes and may cause more harm than good.