How to Prevent an Ice Dam from Causing a Roof Leak
An ice dam is caused by snow build up. On sunny days the snow melts and runs off the roof in its normal fashion. When you have several days of cold weather and snow with minimal sunlight, your roof may get ice dams. These are caused by heat escaping from the interior of your home and into your attic. It then radiates through your shingles and causes the snow to melt. Since heat rises it causes the upper layers to melt and run down near the edge of the roof where it refreezes into ice. The ice builds up and causes the water that runs down the roof to be trapped behind the ice dam. The water then seeps under the shingles and comes into your home. Usually you can tell if you have an ice dam problem by water stains on the walls near the edge of the ceiling.
The big problem with heat build up in the attic is usually improper ventilation. If your home is older than 10 years you may not have the proper ventilation in your attic. Your soffit should have ventilation holes down its entire length. By installing new vinyl or aluminum soffit you can help to prevent ice dam buildup. This is just one of the steps necessary for prevention of this water damage.
Check your attic insulation. By checking the R factor for your area through your local building department you can determine if your attic has been properly insulated. You may need to have your insulation re-blown into your attic. Proper venting along the soffit is very important also. Check to see if your soffit is not blocked by insulation. If it is you can buy insulation batting and install it your self very cheaply or hire a professional at a modest price. These simple foam barriers allow air to travel into the soffit and around the insulation.
Your roof should also be vented properly to allow for hot air to escape. By having a ridge vent installed you have a good chance of not having an ice dam build up again. The theory is that hot air escapes from your home into the attic. Since hot air rises it will flow out of the ridge vent, the highest point on your roof. It pulls the cold air from the soffit and keeps the attic cool enough to prevent an ice dam. It does cost a lot of money to install a ridge vent. Many times, this is done during a re-roofing of the shingles. If you have a gable end on your home, you can install a gable vent at a much cheaper price. These work almost as well as a ridge vent.
By making sure these areas of your home are adequately vented and a proper flow of air is achieved, it’s a good chance you will not get an ice dam. If these steps are already installed and you still have an ice dam, your roof may not pitch properly. Commercial applications of chemicals to prevent ice from forming are good solutions to this problem.
