What is an Ice Dam and How Can I Prevent and Remove Them?

Ice dams are something that all homeowners living in snow-prone climates should know about. Ice dams form from excess heat being trapped in the attic space or roof cavity. This can be a result of inadequate insulation, inadequate or missing vapour barrier, and/or improper attic ventilation. They are created when snow accumulates on the roof which then begins to melt as a result of the excess heat below the roofing. The water runs down to the edge of the roof or gutter, where it is much cooler, and it then refreezes. This process builds up a blockage of ice on the eave which the melting water cannot move past, which causes the water to pool and back up behind the dam.

Most roofing types are designed to shed water, but not to hold water. Because of this, the water can eventually find its way through the roofing into the attic space or roof cavity, and eventually into the living space of the home.

Ice dams can cause interior water damage such as ceiling leaks, damage to interior walls and insulation, and mould and mildew from the excess moisture in your home. On the exterior of your home, ice dams can also tear off gutters, loosen and damage the roofing, and even cause wood rot to the structure.

It’s easy to recognize an ice dam. If there is a layer of ice on top of your roofing at the eave, then you have an ice dam forming. The thicker it gets, the more water it can hold back.  

Photo: Yoku Shimizu

So, if your home is prone to ice dams, what can you do?

Prevention is the best step you can take to stop ice dams before they can form.

Long-Term Prevention

The only long-term solution if you have ice dams forming regularly is to lower the temperature in your attic space or roof cavity. A professional will need to be consulted with to find a solution to prevent heat loss from inside the building into the attic or roof cavity, and/or increase the ventilation in the attic or roof cavity. They can do this by either increasing the insulation R-value, sealing all the leaks through the vapour barrier, installing vapour barrier, or increasing the ventilation in the attic or roof cavity.

Short-Term Solutions

1. Clean debris from gutters before it snows so water can escape off the roof.
2. Install heat cables on the eaves to minimize ice buildup.
3. Use a roof rake to remove snow from the roof so it doesn’t have a chance to melt and refreeze.

But what if it’s too late to prevent an ice dam and you already have one? There are things you can do to lessen any damage ice dams may cause.

1. Use an ice melting compound on the ice dam that is safe for gutters.
2. Hire a roofing company to remove the ice dam off the roof.

Ice dams are a common issue for homeowners but can prevented and removed before damage is caused. Damage from ice dams is also likely covered by your home insurance policy. For more details on Sandbox Home Insurance, click here or reach out to your insurance broker!