How to Prevent Ice Dams on Your Roof

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For the most part, it’s easier to prevent problems than fix them. Preventing ice dams is no exception.

Icicles and ice dams form when snow melts and runs down a roof refreezing near the edge. Certain conditions need to exist for this to happen. Specifically, part of a roof needs to be warm enough to melt the snow (above 32 degrees F) while the edge remains below freezing. And while you can’t control the outdoor temperature, you can take proactive measures to keep your roof and attic on the cold side.

How Do Ice Dams Form?

Heat typically escapes through the ceiling and into the attic where it warms the wood and shingles above. Even though outdoor temps may fall below freezing, the warmed section of a roof melts accumulated snow, thus causing water to run down the roof toward the edge of the area not being warmed where it refreezes and creates a rim of ice. This cycle can eventually cause an ice dam.

Ice Dam Prevention

Preventing ice dams is fairly simple – keep your attic and roof cold. Wondering if yours is cold enough? When it snows, a cold roof will have a blanket of snow while a warm attic will soon develop clear spots where snow has melted. Icicles hanging from the eaves is another sign of a warm roof. Follow these tips to ensure your attic remains cold enough to prevent ice dams.

• Inspect attic insulation. Warm air rises. If your attic lacks insulation, that warmed air will keep climbing and warm the roof. The recommended amount of fiberglass or cellulose insulation is 12 to 14 inches.
• Close up air leaks. Go into your attic (wearing a dust mask, long sleeve shirt and long pants), pull back the insulation and seal up visible gaps or cracks with caulk, foam, or similar material.
• Add roof and soffit vents if needed. Roof and soffit vents draw in cold outdoor air and push out warm attic air, thereby cooling the attic and roof. A roofing contractor can determine whether your attic has adequate ventilation.
• If you’re due for a new roof, consider adding an adhesive ice and water barrier that adheres to the roof decking and waterproofs it.
• Carefully rake the snow off your roof after a heavy snowfall provided you can do so safely. Rule of thumb is to rake after about 6 inches of snowfall. Never use a roof rake while standing on a ladder.
• Install heat cables. These high-resistance wires are mounted on the edge of a roof in zigzag patterns and plug into an outdoor GFCI outlet. They are especially helpful if your roof is prone to ice dams. Remember to route the snowmelt away so it doesn’t refreeze along the roof’s edge – and don’t forget to run a heat cable inside a downspout so that it doesn’t clog with ice.

That sounds like a lot of work, right? Well, while it may be for most homeowners, it’s just another day on the job for Zaman Roofing. So, if you’ve been dealing with ice dams for a good many years, contact us today to make them a thing of the past and better protect your home.