Attic Ventilation: The attic temperature should be the same as the outside air. An attic that is kept well ventilated will keep the exterior of your roof uniformly cold. If your roof stays cold, the snow will not melt from the bottom and the risk of ice damming will be minimized. Soffit venting should be clear and unobstructed to allow fresh air to cycle in and allow the warm air to escape through the upper roof vents. Sufficient soffit ventilation surrounding the house is necessary. Inexpensive Styrofoam baffles are recommended to keep the soffit vents clear of insulation to allow for proper air uptake into the attic space.
Reducing Heat Loss into the Attic: If a house has many warm air leaks, it may be impossible to add enough attic ventilation to overcome the resulting heat build up. Addressing the causes of warm air leaks in the attic is also very important in the prevention of ice damming. Listed below are some common problem spots that can be addressed to minimize warm air leaks into the attic space:
- Attic access hatch – an attic hatch door needs to be both insulated and weather-stripped
- Insufficient attic insulation – An attic that is insufficiently insulated will allow heat from the interior of the home to penetrate into the attic space.
- Potlights – Potlights are mounted directly into the ceiling/attic space and require the ceiling to be cut open causing obvious voids for warm air to penetrate. Pot lights generate a lot of heat and could pose a fire hazard if insulated improperly. It is recommended that you contact a professional to ensure any potlights are insulated properly.
- HVAC Registers – If the house has ductwork running through the attic the ductwork should be well sealed and insulated.
- Other ceiling fixtures – Ceiling mounted electrical devices like lights and bathroom fans should be sealed at their boxes.
Poorly placed eavestroughs: Poorly placed eavestroughs prevent snow and ice from shedding off the roof properly. This is less of an issue on its own, but a contributor when other factors like poor ventilation exist.
Recent changes to mechanical equipment in the home: An upgraded mechanical system (i.e. upgraded furnace system) can cause negative air pressure in the home particularly if the contractor did not pay careful attention to the required fresh air intake required for the appliance. During the course of a new system installation, the vapour barrier in the attic may also have been breached causing more warm air leakage in the attic.
A combination of any or all of the above factors can greatly affect the risk and severity of an ice dam occurring on your roof.
A Home Energy Audit can assist you with detecting problems in your home or attic that may lead to problems with ice damming, and can provide recommendations to improve the energy efficiency in your home. For more information you can go to The Ontario Ministry of Energy website at www.mei.gov.on.ca
Although removal of the ice would seem to be a solution, there are no practical ways to remove the ice without the potential of damaging the shingles or other roof components. There is also a great risk for personal injury. The shingle manufacturers warranty may also be rendered invalid as a result of ice dam removal.
Due to the factors involved in the causes and formation of an ice dam, DeLuca Roofing Inc. cannot be held responsible for leaks or damage caused as a result of ice damming.