Farm building safety should not be neglected during the winter, especially with the threat of snow loads, which can cause the roof on a farm building to collapse.
Snow loads are the downward force on a building’s roof accumulated by snow and ice. Here’s how to protect yourself, your building, your equipment and your livestock from the damage a snow load can cause.
1. Know your area’s snow loads.
In Wisconsin, residential snow load requirements generally range from 30 to 60 pounds per square foot, depending on location. Each zip code has a different snowfall average, and therefore, different snow loads.Use
Applied Technology Council’s Ground Snow Load by Location tool to determine how much weight your building needs to accommodate.
2. Calculate how much snow your roof can handle.
Agricultural structures are not included in Wisconsin’s Uniform Dwelling Code, which dictates minimum snow loads. But it’s still important to calculate the snow load for each of your farm buildings.
How can you calculate your roof loads?
Use this formula provided by the
Wisconsin Cooperative Extension Service to calculate an estimated snow load: Calculated Roof Loading (lb/ft2) = Depth (ft) x Density (lb/ft2/ft depth). The approximate density (lb/ft2/ft depth) is: light snow=5-20; packed snow=20-40 ;packed snow with ice=40-58; ice=58.
3. Plan for snow loads before you build.
Even at minimum loads, if the roof isn’t built to handle the weight of snow, your entire farm building could collapse. Modifying a building to meet your area’s estimated snow loads, however, can be time-consuming and expensive.
4. That’s why you should always plan ahead and factor snow load into your roof design.
Here are some tips to keep in mind when meeting with your builder:
- – Use machine stress-rated lumber to know the exact strength of every piece used in construction;
- – Build your MSR-made trusses to be sturdy and have truss plates designed to support large loads of snow;
- – Consider prevailing winds and building orientation – your building should be designed to accommodate uneven snow distribution;
- Build drainage that will drain snowmelt away to avoid pooling aside your building.
5. Keep barns and buildings clear of snow without putting yourself in harms way.
Clear snow whenever you see more than four feet of dry snow or more than two feet of heavy snow or ice on the roof.
Your building may be able to handle a snow load for several days or weeks, but the weight will cause more damage as time increases. Use a snow rake with a long extension arm to remove snow while standing safely on the ground.
If you’re working on the roof, use the appropriate safety harnesses and secure ladders. Make sure everyone is a safe distance away, since snow can suddenly fall and bury people or animals below.
6. Monitor your roof for signs of structural distress.
Keep a watchful eye on your roof all winter, especially on buildings with considerable loads. Look for the warning signs of overbearing loads, such as sagging, misaligned or bowed trusses and creaking sounds.
Metal buildings, unlike wood buildings, however, give virtually no warning before collapsing.
7. Confirm you have the correct insurance coverage.
Talk to your insurance company before a winter storm hits to ensure peace of mind!
At Rural Mutual, we can offer coverage for your roof or building due to collapse from snow loads, including replacement cost for equipment and animals that are stored in the building.
When it comes to managing snow loads, it’s best to plan ahead, stay on top of it and contract a professional, when necessary.