Living in Kitchener-Waterloo, ice dams are a common problem all homeowners deal with during the winter season. However, for those with flat roofs, solving ice dam problems can be a little more complicated. With the same natural drainage of a sloped roof, how are flat roofs affected by ice dams?
This article will answer just that, along with more frequently asked questions about ice damming on flat roofs.
Do Ice Dams Form on Flat Roofs?
Yes, ice dams can form on flat roofs. Ice dams start with an accumulation of snow on the roof’s surface, and snow can easily accumulate on flat roofs.
However, because of the difference in structure, ice dams form differently on flat roofs vs. sloped roofs.
On a sloped roof, ice dams typically form on the eaves of the roof.
However, on a flat roof, ice builds up around roof drains or in low spots where melted snow pools and refreezes.
Are Flat Roofs Prone to Ice Dams?
Yes, flat roofs are more prone to ice dams because they don’t have the natural slope that helps snow and meltwater drain away. As a result, it’s easier for water to pool and refreeze, creating an ice dam.
Outside of drainage, attic space and insulation also plays a role. Many flat-roofed homes lack an attic space, which means less insulation between the heated interior and the roof surface. This can cause more ice dams to form, especially compared to a home with a well-insulated attic.
How to Prevent Ice Dams on Flat Roofs
- Improve Roof Insulation: The best way to stop ice dams from forming is to ensure the temperature across the roof surface is balanced with proper insulation. This prevents the temperature changes which lead to ice damming. Foam insulation is a great choice for preventing ice dams and moisture build-up.
- Keep Roof Drains and Scuppers Clear: Flat roofs rely on drains and scuppers for water removal. Clear debris like leaves and twigs before snowfall and periodically throughout the winter to prevent blockages.
- Remove Snow Regularly: Removing snow is important for preventing ice dams. It also helps avoid other common roofing issues caused by snow, such as a collapse or leak. For your safety, please hire a professional for help removing snow from flat roofs.
- Install Heat Cables Around Drains and Gutters: Heated cables or mats can help keep critical drainage areas open by melting ice around drains and roof perimeters. These systems are especially useful in buildings with limited insulation.
Should I Get a Pitched Roof to Prevent Ice Dams?
Switching from a flat to a pitched roof can help reduce ice dam formation, but it’s not always the most practical or cost-effective solution. A pitched roof can help reduce the amount of ice dams you get, but it’s not a guaranteed fix.
Cost and Structural Considerations
Converting a flat roof into a pitched one can be a major construction project, requiring structural reinforcement and design modifications. Unless the roof is already due for a full replacement, the cost will often outweigh the benefit.
Pitched Roofs also Have Ice Dams
In snow-heavy areas such as Kitchener, a pitched roof may reduce the frequency of ice dams, but it doesn’t guarantee they won’t form. In fact, ice dams on sloped roofs are very common due to poor insulation and ventilation.
Consider Upgrades Instead
You can solve the root causes of ice dams through better insulation, regular maintenance, and heat cable installation — without needing to switch to a pitched roof.
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