Before Canada’s icy winter begins, fall is a great time for homeowners to review what state their attic insulation is in. Insufficient attic insulation increases the possibility of ice dams forming on homeowners’ roofs. This phenomenon can lead to unwanted and costly leaks and roof shingle damage. Carry on reading this blog to learn everything you need to know about attic insulation and ice dams.
What is an ice dam?
An ice dam occurs when ice builds up on the eaves of sloped roofs belonging to a heated home. Heat loss from the home contributes to melted snow flowing down to the eave and freezing there. This creates a series of dangling icicles that hang towards the ground below.
When these dangling icicles are in place, it obstructs meltwater from being drained properly. The result is a backup of meltwater which often causes roof water leakage and associated damage to the internal structure of a home.
What causes ice dams?
Three factors work simultaneously to create an ice dam. Firstly, there’s heat loss from your home, secondly there’s the amount of snow cover, and thirdly, is the outdoor temperature. Ice dams will only form if your home has snow on its roof. Typically, your upper roof must be above 32°F / 0°C freezing, whereas lower surfaces are below 32°F / 0°C freezing.
Snow that has settled on your freezing upper roof will melt, trickling down to the colder below freezing section of your roof. This meltwater freezes, causing the ice dam. As more and more snow settles on your upper roof surface, the ice dam will expand but only along the colder below freezing section of your roof.
Once the ice dam has formed, any more snow/meltwater gets backed up behind the dam. Remaining in liquid form, this meltwater has nowhere to go except through tiny roof cracks and openings into your attic. It doesn’t end there because depending on the severity of roof leakage, water may percolate through ceilings and exterior walls too.
What damage is caused by ice dams when left uninspected?
Ice dams might look pretty but they should never be left uninspected. The damage caused by ice dams includes:
- Torn off gutters
- Loosening of roof shingles
- Roof and attic leakage
- Water leaks in home insulation
- Ceiling water leaks
- Exterior wall water leaks
- Warped flooring
- Peeling wall paint
- Stained and sagged ceilings
- Mold and mildew growth