How winter can damage your roof
By Cris Carl, Networx
MYTH: The icicles hanging from the roof are so pretty!
FACT: Besides the fact that when icicles start to melt they may fall on your car, or worse – you – ice dams are one of the most damaging things that can happen to your house. Prepare ahead of time – if you have gutters, be sure they are cleaned out before winter sets in. Ice dams are formed when warm air escapes from your attic, essentially when there is not enough insulation.
As snow melts from the warm air, the water drips to the eaves, where it is colder, and freezes – creating a dam. Ice dams can cause heavy damage in a variety of ways, to the roofing material, gutters, or damage below the roof from the "avalanche effect" if the temperature rises suddenly. The best winter roofing situation is to have enough insulation in your attic to create a layer of air between insulation and roof that is the same temperature inside and out. Avoid chipping away at ice from the ground.
FACT: Roofing materials can make a difference in the creation of ice dams.
WHY: Asphalt shingles have a rough surface and will hold onto snow more easily. Asphalt tends to hold onto the snow until it trickles off or evaporates. Metal roofing, especially if there is a PVC coating, is designed to allow snow to slide off more easily due to the smoother surface. You can also install snow guards or heating cables to metal roofing to further avoid ice dams.
MYTH: I have a new home; I shouldn't have anything to worry about when it snows.
FACT: Ah, if that were true. However, homes built before 2010 were not subject to state energy efficiency building codes. So, unless you built your home yourself and you are highly invested in energy efficiency, it's a good idea to remain aware of possible problems during heavy snowfalls.
MYTH: Solar panels won't work when it snows.
FACTS: Solar panels will work if there has been light snowfall. If you have a heavy snowfall, they may not generate electricity for a short time. However, due to the slick, angled, and often black surface of solar panels, the snow will slide off in fairly short order. If you are very concerned about this potential problem, have your solar panels installed on the ground. Solar panels installed on the ground are more steeply angled than roof panels.
FACT: Snow insulates.
CAVEATS: Depending on how well your roof is constructed, a layer of snow on your roof (that is well insulated on the inside), will provide additional insulation. However, if you experience heavy and/or frequent snowfall, you may need to take measures to remove snow from your roof if the layer is more than two feet deep.
FACT: Too much snow on your roof can cause collapse, leaks, or damage when the snow slides off the roof onto whatever is below
HOW TO DEAL: For low roofs, you can use a snow rake. Otherwise, you may want to hire a professional. It can be tricky and dangerous to remove snow from a roof. Check for any sagging in your roof via a trip to the attic. If the roof is sagging, get professional help as soon as possible. If snow piles up around the house, it will help keep heat in and cold out. The snow blocks warmth from your home being dissipated by wind.
FACT: Snow melt products can damage your home.
WHY: Snow melt products create a faster freeze/thaw cycle, which can crack concrete and asphalt. Since concrete is poruous, the corrosive damage from "salt water" adds to the potential damage over time. The actual chemicals themselves are toxic to plants and animals. Rock salt and halite are the most damaging, followed by calcium chloride.
Alternatives (green products) are sand, kitty litter, Warm Paw (least expensive at about $17 for a gallon canister). Other products which are much more expensive, but are safe for the environment and pets, are Propellant 49, which costs about $145 for 100 lbs. in pellet form, and a variety of liquid deicers that also require the purchase of a sprayer for the product. Liquid deicers cost $25 to $30 a gallon.