Snow Maintenance Tips
The snowiest month of the year in Michigan is February so…Let’s talk snow!
The weight of snow is a vital piece of information. Whole sections of the building code are based on knowing how much additional weight a structure will need to support due to the typical snow loads in a given area.
There is no foolproof rule for estimating the weight of snow; however, if you know the conditions of which the snow was formed and the conditions under which it was kept, you can come up with a reasonably accurate guess. Snow density will change when it interacts with temperature, wind exposure and depth of the snow. Snow density will increase over time as the snow melts and compacts along with the effects of temperature and wind. Wind rounds off the snow particles and allows them to fit together more tightly. Snow will also be compacted by its own weight, so the deeper the snow, the denser and heavier it will be at the lower portion of the snow pack.
Snow can vary in weight from 1 pound to 30 pounds per cubic foot. Fresh fluffy snow may weigh from 1 pound to 4 pounds when it snows; however, after a few days of normal weather, it may weigh 15 to 20 pounds per cubic foot.
Many times, after an accumulating snow we see people on top of their roofs shoveling in the hopes of preventing structural damage to their roof system. This is a dangerous practice and mostly unnecessary.
In this region of Michigan, all roof structures are designed for 30 pounds per square foot of ground snow load along with a 25% safety factor. These roofs are also designed with consideration to specific construction loading such as pallets of shingles being placed at the ridges awaiting application.
If you are considering removing the snow from your roof, here are a couple of factors to think about.
- With the exception of a 500-year snow event, and/or a faulty or damaged roof structure, your roof should not ever become overloaded.
- Accessing and working on a roof with snow on it is inherently dangerous and should only be done by a professional. Please look at this article put together by O.S.H.A. “Falls and other hazards to workers removing snow from roofs and elevated surfaces.” Eye opening!
- Attempting to remove snow from your roof may cause damage to your roof covering and cost you money for repairs in the spring.
Snow will not stay on your roof for very long. The best advice the Building Department can give you after a snow event is to stay warm, safe and let Mother Nature handle the heavy lifting.
If you have any questions regarding these items, please feel free to call DeWitt Township’s Building Department at 517.668.0278.