Now that winter is fast approaching, many homeowners may wonder, Can snow damage my roof?
Truthfully, any form of water can be harmful to a roof, but when the temperature dips below freezing, water and snow can become a more serious problem.
What's the big deal about ice?
Let's say you get freezing rain with sleet one day when the temperature is hovering around 35 degrees Fahrenheit. Not a problem for your roof... but when night falls, the temperature may drop to 28 degrees Fahrenheit.
Water that got into the smallest crevices during the day will then freeze at night, and when water freezes, it expands, and as it warms up, there's room for more water to sit and freeze over later.
This cycle of freezing, thawing, and refreezing results in larger cracks in your roof. The more often this freeze-thaw cycle repeats, the more moisture gets into the shingles. Eventually, this will cause them to expand and wear out. Leaks can cause water damage and potential wood rot to the wooden framing underneath.
What's the big deal about snow?
Heavy snow can also present some unique problems. Snow accumulation on your roof can weaken the entire roof. Different roofs have different configurations and slopes, which affect how much snow accumulates as well as blowing or drifting.
Drifting snow create places on your roof where snow is piled as high as five times the amount of snowfall. Areas where the roof meets a solid wall or places where there is a lower roof or awning are most susceptible to accumulation.
How do you know when your roof has too much snow on it?
The answer to this question depends on how your roof was built in the first place. In heavy snow areas, roofs are made to bear heavier accumulations of snow. However, a general benchmark for residential roofs is 8 cm (20 lb.) per square foot. If the roof slope is greater than 8 cm (3 inches) for every 31 cm (12 inches) of horizontal distance, melting snow should run off adequately.
Remember, though, that new snow falling on top of old, packed snow weighs more, which may make yesterday's packed snow twice as heavy.
What is an ice dam?
Ice dams form when the accumulated ice and snow on the roof melts but then freezes all along the edges and eaves of the roof. This edge of ice keeps water from running off the roof which can cause water to find its way under the roof shingles and even into the house. Large ice dams have been known to tear the rain gutters and flashing off the roof.
What can a homeowner do to address these problems?
Investing in an inexpensive snow rake will be helpful in removing snow from the roof. For ice dams, homeowners may be able to use a hammer and chisel to chip away at the ice to loosen it. Remember to take the proper precautions when climbing a ladder, especially in icy weather.
Keep a good record.
Creating a tracking record of visual assessments and matching them with a baseline, possibly with photographs, will help homeowners keep track of the cumulative damage done by weather over a period of time. This benchmark will help keep track of any changes occurring.
Joye Roofing offers free, professional roof inspections. Once we complete our inspection checklist, we will give you an estimate on any work which may be needed. Click on the banner below to schedule your roof inspection today!