While Albertans may have differing views on whether the Calgary Flames or the Edmonton Oilers are the superior hockey team, we can all still agree on a few things. Winter is cold, carbon monoxide is dangerous and ice dams forming on your roof is not a good thing. What exactly are ice dams and why should we care? Most importantly, what does this have to do with ventilation?

An ice dam is a layer of ice that forms along the bottom row of your roof’s shingles. During the cold winter months when snow piles up on a roof, it can become heated from the warm air inside the house. This causes the snow to melt and travel down, where it meets the unheated edge of the roof and consequently freezes. This frozen “dam” of ice can then cause water to back up beneath the shingles, leading to damage to the walls and roof structures. Since water expands as it freezes, your shingles will begin to lift and water can become trapped underneath. Ideally, your roof will have another layer of protection or roofing paper installed, however, this is not always the case. We have re-shingled numerous roofs that had previous DIY jobs that had zero protection! Even if there is a layer of roofing paper or protection, a lifted shingle is never good.


One of the easiest ways to prevent this is to ensure you have adequate ventilation. Attic ventilation, for example, is key to ensure that any excess heat that manages to escape into the attic cavity is exhausted properly. As much as we would like to eliminate the warm moist air from the attic, this is not possible, and we, therefore, have to ensure that all vents are open and operating properly. A blocked vent will greatly reduce the flow of air and can cause a buildup of condensation under the roof deck, leading to snowmelt and the dreaded ice dams.

If we imagine our homes like a living, human organism, then the ventilation system of a house would be the lungs. Just as in the human body, we want the air to breathe freely through specified airways, which is why we need proper ventilation to keep the air fresh, healthy and mould-free. Without proper ventilation, you can actually trap harmful pollutants, moisture and even dangerous chemicals (including carbon monoxide) in your home – yikes! Aside from saving your family from a potentially deadly situation of carbon monoxide, or the damaging condition of ice dams formed on your roof, proper ventilation keeps your home energy-efficient and can even reduce heating costs. This is what we call a win-win!


Curious if your home has proper circulation or noticing that an ice dam is starting to form on your roof? Contact us today for a free estimate and have one of our highly skilled roofers come and take a look. Located in Calgary, we completely understand Canadian winters, so please check out our services or get in touch with us here.