Ice damming problems and solutions

BY: JAY BRIJPAUL 

Winter is a cocktail of extremes. Temperatures fluctuate from warm to cold and the process creates thawing and freezing. This is one of the causes of ice damming which can lead to water damage. Ice damming is common when the snow melts and refreezes on top of roofs. One of the signs of ice damming is the icicles hanging from the eaves.

Ice dams are slabs of ice along the perimeter of the roof and, when frozen, are harmless like the icicles. On warm winter days, melting snow pools along the dam and seeps back upwards, under the shingles, sometimes as much as five to ten feet. With no barrier, it finds its way into soffits and along the walls. Water will travel in many directions and sometimes where the leak appears is not the problem spot. I recall in one of my client’s homes, we thought that it was a leaky basement. It turned out that water was travelling along a conjugate from the roof to the basement floor.

The first sign of water damming may appear as rust spots along drywall screws. Sometimes you will notice bulging paints and in extreme cases damp drywall. If undetected, it can result in mold infestation and poor air quality. Fortunately, there are cures for ice damming. Now is a good time to find problem spots. Take note where icicles are forming and tackle the problem on a dry summer day.

In many homes, heat escapes along the ceiling, into the attic and warms the wood and shingles. Shingles are attached to plyboard with nails, a conductor of heat. Although the outside temperature is below freezing, snow melts along the warmer areas and the water runs down to the edge, refreezes and eventually forms a dam. The best way to prevent damming is to avoid heat loss. There are many benefits here because, with less heat loss, utility cost will drop and at the same time, you will prevent water from seeping into the attic. To keep the attic temperature cold, we need to make a few adjustments.

Air leaks into the attic usually result is around 30% of heat loss. Most of the air leaks are from around vent pipes, ceiling fans, access hatches, light fixtures and unblocked drywall gaps between the exterior walls. Large gaps can be blocked with extra insulation such as spray foam and a coat of silicone around washroom fans and light fixtures will certainly assist. Weatherstrip and insulate the access hatch. Kitchen vents should be vented directly to the side of the home and not through the attic and roof. Washroom vents and fans should be vented with insulated vents to prevent condensation and heat loss.

Now that all the gaps are sealed, the next step is to check the level of insulation in the attic. The recommended thickness is about fourteen inches. A few extra inches of insulation can save money from consumption cost; in the winter with heating and in the summer with air conditioning. The blown-in insulation is better than the regular hand placed because of fewer disturbances and better coverage. It is best to hire a contractor for this job.

Ventilating the attic flushes out hot air and allows cool air to circulate freely. The attic and outdoor temperature should be around the same to prevent condensation. The best type of roof vents are roof turbines, known as whirlybirds. Vents should be installed around the soffit in every other rafter space as well. The rule of thumb is that one square foot of vent is good for 300 square feet of ceiling area. Make sure that the soffit vents are not covered with insulation. This will block the air flow.

Water is unique in that it expands when frozen. As it seeps into cracks and crevices, over time, they will grow. As the proverb goes “A stitch in time saves nine”. Our home is one of our best investments. An insulated attic is certainly worth the cost with monthly utility savings and expensive roof damages.