Updated January 1, 1 . AmFam Team
Many factors go into managing the snow load on your roofs. Winter storms vary, from one to the next. Some carry wet, heavy snow that started out as sleet while other frigid-temperature snowstorms can drop many inches of light, powdery snow. Because different types of snow weigh different amounts, it’s important to know what has accumulated on your roof. It’s also important to know how much weight is too much for your roof to safely handle.
The best way to avoid a potential roof collapse due to a snow overload is to get that snow off your roof safely:
Pick up a snow rake. Find these at local hardware or big box stores. Many come with a telescoping handle that allows you to reach up onto the roof and pull snow down.
Hire a snow removal contractor. Trained in safely tethering and working on the roof, these professionals have both experience and the tools to get that snow down off your roof.
Move fallen snow away from the building’s foundation. If your outbuilding has a basement, in order to prevent winter flooding, you’re wise to remove the snow away from the side of the building. Fire up the skid-steer to carefully scoop up and relocate that snow so it won’t harm your structures. Also, be sure to relocate snow to areas that slope away from walkways and parking lots. That way, meltwater draining away and later refreezing will be less of a hazard.
Grab the insulated bibs — and dress smartly for that frigid winter weather — taking a close look at your roofs. While you’re out there check for symptoms that may be telling you a roof collapse is in your near future, like sagging and sounds of creaking. If you spot these signs, it’s probably time to take action.
The northern states of the U.S. can usually handle loads anywhere from 25-60+ pounds per square foot of snow in a given season, though this figure can vary wildly depending on seasonal intensity and location. Other things that can impact your roof’s snow load are the age of the building and its structural condition. To learn about what your area’s average snow load is, input your zip code into the Applied Technology Council’s hazards by location tool (Opens in a new tab), selecting first the Snow tab.
Trying to figure out how much snow weighs per square foot depends on its density. Estimating the weight of snow is pretty simple. Typically roofs are rated for around 25-30 pounds per square foot. Believe it or not, four to five feet of fresh light powder weighs the same as four to five inches of ice.
Each of the figures below weigh the same as 1 inch of water per square foot, or 5 pounds per square foot:
10-12 inches of fresh snow. Your roof may be overloaded when fresh snow heights range around four feet and above.
3-5 inches of older, packed snow. Your roof’s load limit is typically reaching its limit when heights of packed snow range around 2 feet and above.
1 inch of ice. The load bearing capacity of your farm's roofs may start to be compromised when ice accumulation extends from four inches and up.
If your outbuildings are somewhat isolated and exposed to a wind that typically flows in the same direction all winter long, you may be able to reduce the amount of snow on your roof. By strategically placing snow fences upwind of your outbuildings, you can build up surface friction in the wind.
As the wind travels over the open plain of your acreage, well-placed snow fences disrupt the flow of air as it’s carried across the land. They cause a drift to form on the downwind side of the fence, keeping that snow off your roof. They’ve also been used to reduce snow buildup on roads and highways too. Here are a few more ways to help keep snow on your roof to a minimum.
Much of the work to prevent snow accumulating on your roofs should happen during the warmer months. From installing a snow fence in late fall to planting a tree line of conifers, it’s going to take planning, budgeting and a fair amount of labor to help to keep your roofs healthy for the winter weather to come.
Plant a dense tree line. Because trees act as a windbreak too, planting thick evergreens close together can accomplish the same goal as a snow fence. Because they’re going to grow taller and denser over time, they’re likely going to do a better job of reducing blowing snow as they mature.
Replace your roof with a metal one. Asphalt is great at keeping the water out in warmer weather but during the winter months, it’s also great at securing the snow to your roof. If you’ll need a new roof soon, think about converting it to metal shingles or metal roof panels. Their smooth surface can help that snow glide right off. And they’re better at keeping your building safe from wildfires.
Build new structures with steeply-inclined roofs. If you’re planning on any new construction, designing your roofs with a steep pitch will help to shed that snow naturally. Add steel roofing material on top, and you can really increase your odds of a safe roof all winter long.
Looking at all the ways winter weather taxes your buildings, it’s good to know that American Family Insurance offers a wide array of supplemental coverages that can really help to put your mind at ease when the wind begins to howl and the snow starts accumulating. Because Mother Nature can be so unpredictable, our farm personal property insurance endorsements can help protect your family and your finances from the unexpected. Contact your American Family Insurance agent (Opens in a new tab) for details on these and other optional endorsements to get custom-designed coverage for all of the key aspects of your operation.