Looking for another reason for considering a standing seam metal roof system – well check this out?
Over a 36-hour period in Massachusetts last month, there were more than 70 reports of roof collapses or buildings with potential structural damage from the weight of snow and ice loads on roofs. The majority took place in eastern Massachusetts but they could have been almost anywhere in the continental United States given the severity of the weather we’ve been experiencing.
In many instances, homes and businesses were evacuated as a result of collapses or safety concerns resulting from indications of structural weaknesses from rooftop snow loads. These conditions are directly attributable to prolonged cold weather and repeated snowstorms punctuated by short periods of rain that are absorbed into the snowpack adding more weight. The threat can be alleviated by removing the rooftop snow on homes and commercial buildings. That’s one short term solution.
The other is to re-valuate the kind of roof and consider replacing it with a standing seam metal roof. Certain kinds of flat and low pitched roofs can be at risk of collapse with heavy snow and ice accumulation. Meanwhile structures with roof valleys and lower roofs breed snow drifts and can also be dangerous.
According to the Insurance Institute for Business and Home Safety, the average roof can handle a snow load of 10 to 20 pounds per square foot in Mid-Atlantic states, and between 40 and 70 pounds per square foot in New England where there are more accumulations and colder weather.
Lower shallow pitched roofs such as a porch roof need to be designed to hold much more snow than code. This is addressed in engineering manuals and local building code books but may not have been heeded by the builder. A large low slope roof (1 to 5 in 12) with an EPDM membrane can be problematic. According to the Institute, below a certain pitch, shingles are no longer an option. Steeper pitched standing seam metal roofs tend to let snow slide more often, preventing a serious buildup – unless a valley or dormer prevents this from happening.
One other important note to remember when you’re considering the weight of the roof itself and the weight of the snow. A metal roof is, on average, 50 percent lighter than an asphalt shingle roof, and 75 percent lighter than concrete tile, fiber cement shakes and slate. Metal roof systems in most cases weigh between one to three pounds per square foot. The actual weight is dependent upon metal gauge and profile of the panel. Asphalt shingle material weighs two to three and a half pounds per square foot and concrete tile five and half to 10 pounds per square foot. Severe winter weather can’t be avoided, but heeding this information and considering a standing seam metal roof may help prevent a serious and costly problem.