Snow on Roof? Should you remove it?
March 13, 2001
Don’t be too hasty to shovel the snow off your roof most roofs in our area are designed to handle the snow load of a typical winter, being built to hold 40 pounds of snow per square foot. How can you tell if the snow load on your roof is excessive? It’s tough to know for sure, because the weight of snow varies greatly. Light fluffy snow may only weigh about 7 pounds per cubic foot. More average snow weighs 15 pounds per cubic foot, and drifted compacted snow may weight 20 pounds or more.
The decision to shovel off a roof is a case-by-case decision. Watch for deep drifts caused by surrounding trees or buildings. Roofs that have more than one level often accumulate deep drifts, but those roofs should have been built to carry that added load. (Insurance records suggest that 75 percent of snow-related structural damage comes from drift loads on two-level roofs.) If in doubt, inspect the rafters and trusses and if they are bending downward or flexing to the side, the roof is in danger. Before making the decision to shovel off a roof, take into consideration that you can cause damage to the roof by doing so.
Cold temperatures make shingles brittle so they break easier. You’re also more likely to remove many of the little pebbles from the surface of the shingles, shortening the life of your roof. Remember also that snow and ice can make the job dangerous-metal roofs can be especially slippery. Watch out for power lines, as well
For more information, contact the CSU Moffat County Cooperative Extension Office, 539 Barclay Street, 824-9180.