Ice Dam Solutions for Your Roof

ice damJust above the sparkling icicles decorating the eaves and the gutters of your home something less lovely can grow — that thick ridge of ice known as the dreaded ice dam. Your home need not remain at the mercy of these damaging dams, though. You can come to your home’s rescue.

How Do Ice Dams Form?

Ice dams form because the warm air in your attic warms the areas of the roof that are directly above the attic, but that warm air doesn’t extend to the eaves of the roof. The snow that covers the warm areas of the roof melts, but refreezes over the eaves. As winter progresses and the snow repeatedly melts off the roof and refreezes over the eaves, it becomes a dam that blocks the water from the melting snow from reaching the eaves and refreezing. Instead, the water remains liquid, and since it has nowhere else to flow, it finds its way under the shingles and into your house.

What is the Potential Damage from Ice Dams?

Ice dams can loosen the shingles on your roof and become so heavy that they tear down your gutters. Once the water from the melting snow finds its way under the shingles and into your home, it saturates the insulation in the attic, reducing its R-value, and inviting mold and mildew. The water from the melted snow can also stain the ceilings of your rooms and cause them to sag. It can cause the paint on your walls to peel, and it can warp your floors.

What are the Best Ice Dam Solutions in the Middle of Winter?

If, in the middle of winter, you discover snow piling up on the eaves of your roof while the snow over the attic melts, the safest way to deal with it is to remain on the ground and use a wheeled, long-handled, aluminum, snow rake to pull the snow down from the roof. If an ice dam has already formed, roofing companies can use steamers to melt ice dams with a pressurized stream of hot water.

If you discover water from an ice dam is leaking into your attic, Tom Silva, general contractor for This Old House, suggests taking a box fan to the attic and using it to blow a targeted dose of cold air at the underside of the section of roof where the leak has appeared. Silva says that the leak will stop “in a matter of minutes” as the cold air freezes the water.

Steps to Prevent Ice Dams before Winter Comes

The key to preventing ice dams from forming is to keep the temperature in your attic as cool as the outside temperature in the winter. Insulating and ventilating your attic and preventing warm air leaks into the attic all help. Weather-strip your attic door or pull-down attic stairs and caulk around vents or electrical wiring.

Your attic should have 12 to 14 inches of insulation and one square foot of vent for every 150 feet of floor space. To increase ventilation, add soffit vents around the eaves and a ridge vent along the peak of the roofline. Use baffles to prevent insulation form covering the soffits. Replace older recessed lights with sealed “IC” fixtures that can be covered with insulation.

When you install a new roof, be certain that an ice and water barrier covers the edges of the roof and the areas where two rooflines meet. Rolled asphalt should underlay the shingles over the entire roof.

These tips should prevent future ice dam damage.

April 28, 2015 | Home Improvement Info