Picturesque snow-capped houses and barns are charming, but don’t be fooled by their delicate beauty. Wisconsin winters can be pretty tough – especially on buildings. Most people take for granted the amount of stress their houses, businesses, barns and storage facilities must endure throughout the Wisconsin winter months. These structures support snow and ice, otherwise known as snow load.
Snow has a great deal of weight, and that weight increases immensely when rain, ice and sleet are added to the mix. Two feet of snow on the average-sized roof can be the equivalent of 38,000 pounds, or 19 tons. All of this weight puts stress on your roof and weakens its structure which can cause a collapse. While all buildings are designed to carry some snow load, there’s no guarantee that they will carry the same amount of snow load.
Most homes are required to be built well enough to survive winter’s onslaught, snow load capacity requirements for non-dwelling businesses and agricultural buildings vary greatly. Especially depending where your building is located. Buildings near larger structures, such as other buildings, trees or silos are more likely to collect drift which increases snow loads.
Types of loads on a building structure
A load is the force on a building by accumulated weight. There are several types of loads.
- Dead load – The gravity loads caused by the weight of the structure itself such as the weight of walls, floors and roofs.
- Live load – The load superimposed by the use and occupancy of the building such as people, furniture and materials.
- Collateral load – Include objects placed on or hanging from the roof of a building such as an air conditioning or ventilation system, sprinkler system or special lighting.
- Environmental load – Occurs as a result of environmental conditions including snow, wind and earthquakes.
Dead, live and collateral loads are known entities that can be accounted for in the building design process. But environmental loads, such as snow, are variable. Snow load capacities depend on the building type, location, occupancy and primary use. For non-commercial, agricultural buildings, snow loads can range from 12 to 40 pounds per square foot depending on the region.
We know Wisconsin gets quite a bit of snow especially in the northern half of the state which commonly experience record snowfalls. To see the average annual snowfall in your area, visit the National Weather Service.
how to remove a Snow Load from the roof
The good news is, timely snow removal from roofs can prevent a collapse from happening. Excessive snow accumulation is one of the biggest threats to structures. If you need to remove snow from a roof, use caution.
Falls from roofs or ladders going onto a roof can easily occur on snowy, slippery surfaces. Removing snow can allow the snow up slope to suddenly slide down, burying people or animals below. It’s best to stay on the ground and use a roof rake from a safe distance away to reduce risk. The rake has an extended handle, which enables you to pull snow off the roof from the safety of the ground. Most hardware and farm implement stores carry snow rakes. Tip: Purchase one early in the season while supplies last.
When thinking about snow on the roof, make sure you’re properly covered before winter storms roll in. We can help protect you if your building has a loss due to a snow load. Contact your local Rural Mutual agent for additional information.
