If you’re like most Twin Cities homeowners, your roof has a pile of snow following last weekend’s storm, unless you’ve already been up there with a roof rake or a shovel. And you may already have some ice build-up or icicles at the edge. Some people are tempted to leave those picture-perfect icicles in place, and you may have heard that snow on the roof can be helpful, but the truth is that both snow and ice on a roof pose hazards – both to people and the structure.
Although snow and ice on roofs both have the same cause (snowfall), they can cause different problems, and how you deal with them is different. The only real similarity is that both have the potential to cause problems if they develop significant weight. Here are the basics.
Snow
You may have heard the term “snow load” in reference to a roof. Basically it has to do with the pressure a build-up of snow is putting on the roof. One cubic foot of snow can weigh up to 30 lbs., and even more if it is rained on. Snow typically weighs more per square foot than ice.
Keep in mind that your roof structure bears the majority of the weight of the snow, so it’s important not to let it build up. This is especially true for older homes. A high snow load has the potential to damage a roof. Other factors involved are the age of the roofing and the quality of the installation. Generally speaking, the greater the “pitch” of a roof (the angle of the steepness), the less prone it is to snow build-up. Also, attic insulation that does not provide for adequate air circulation can contribute to the problem.
Ice
The main danger from ice on a roof is the formation of ice dams at the eaves, which has the potential for doing severe damage not only to the roofing but to the underlying structure, soffits and fascia, and rain handling systems. Those beautiful calendar-picture icicles dangling from your eaves are a disaster waiting to happen. Ice dams permit water to seep under the roof, causing leaks, rot, and mold and mildew formation.
Snow and Ice: A Nasty Combination
The real problems come in when snow and ice build up together. The snow, due to its weight, puts a stress on the roof structure, while the ice dam traps water from melting snow. With each additional snow accumulation, there is more pressure on the roof as well as more ice dam build-up from melting snow. Emergency roof repairs could be the result.
Taking good care of your roof means removing snow and ice quickly and safely. While you may be able to shovel or rake off the snow, it may be preferable to have an experienced professional take care of removing the ice dams so that you don’t inadvertently do damage to your roof or the surrounding elements. If ice dam formation is a recurring problem, consider seeking out the advice of a professional roofing company for steps that you can take to correct the situation.
