With winter comes challenges. Whether it’s mammoth accumulations of snow, wild winds, frigid temperatures or huge weather swings that leave you bundling up one day and considering pulling out the shorts the next, Mother Nature knows how to put on a winter show, ensuring Canadians in most of the country keep an eye to the sky, or in some cases to the snow on their roofs.
In fact, farmers should take some time to assess snow loads on farm building roofs. Heavy snow burdens combined with uneven snowdrifts and various freeze-thaw cycles may be putting undue strain on rooftops. Although not common in Western Canada, if the roof of a barn, shed, storage facility or other farm building were to fail, the damage to person and property could be catastrophic.
The amount of snow a roof can withstand is determined by many factors, including the roof pitch, depth and spacing of rafters and trusses, shape and location of the snowdrift, depth and density of the snow and the duration of the snow accumulation.
While most roofs should be built to withstand normal snow loads, take special care to assess each roof section carefully.
- From the exterior, how deep is the snow in places?
- Are there valleys that have collected an exorbitant amount of snow?
- Do you have multiple roof levels with shorter/shallower sections that have been catching large amounts of snow from the taller/steeper sections?
- Is the snow light and fluffy or wet and heavy?
- How long has it been there?
- Is your roof exposed to the wind and more vulnerable to ever-changing snowdrifts?
- If you can, check the roof interior. Are the rafters bent by the weight of snow?
- Have you heard unusual sounds of strain coming from the roof?
- Are doors jamming unexpectedly?
The answers to these questions can help you assess the situation and determine if snow clearing is necessary. Once you have made the decision to remove the snow, you’ll need to conduct a risk assessment based on your clearing method.
If you can, remove the snow from the ground. Use a roof rake, taking care to ensure your work area is clear. Remove the snow from the bottom upwards to avoid unmanageable snow volumes. Work your way around the roof rather than clearing one side first, or work with a buddy on the opposite side of the roof. These methods will help prevent uneven snow loads. Be cautious of clearing too close to the roof surface, and don’t scrape or chip at snow, as this could damage the roof.
If snow can only be cleared while on the roof, assess surface conditions. A steep pitch is more dangerous than a shallow one, a metal roof is more slippery than a roof with shingles and ice is more treacherous than snow. If you are still undeterred, take all necessary precautions for safety.
Consider purchasing a professional fall-restraint system before you get started. Homemade or jerry-rigged harness systems may not protect you from a fall and could result in serious injury. Some building supply stores and many safety equipment retailers carry roofing kits, which for a few hundred dollars include a safety harness, shock-absorbing lanyard and rope and safety anchors. Additionally, wear appropriate footwear and don’t work alone. Instead, work with at least one buddy so you can remove the snow carefully and evenly from both sides of the roof.
Ensure your snow-clearing area is free of people or animals. Consider having a third person act as a spotter from the ground level, using cellphones to communicate back and forth and call for help if needed. Use a snow rake to clear the snow, but be aware of overhead power lines. Be cautious of overexertion and use safe ladder practices to climb onto and dismount from the roof.
If you aren’t confident about your ability to venture onto the roof and clear the snow safely, call a roofer with the necessary equipment and experience instead. Like many other tasks on the farm, you must assess the risks to determine the best course of action and then put a plan in place for carrying out that task in the safest way possible.