Have you been carefully monitoring that gravity-defying overhang of snow that sits atop your roof? Glistening beautifully in the sun, a heap of snow is fixated at the edge of the roof line, as it has been for days, surely it will linger for a few more days, right? Sorry, there’s no way to guarantee just how long it will stay put. In fact, avalanches are unpredictable and catastrophic events. The snow may fall wherever and whenever it wants to – a sidewalk, a car, or pedestrians.
Enter snow retention. Snow guards help preserve your metal roof and allow snow drifts and snow-melt to exit the roof in a more controlled manner - avoiding the potential calamity of a rooftop avalanche.
1. Protect Building Occupants and Pedestrians
Safety first! The number one reason to install snow guards is to protect the people who walk below it. Ensuring safe passage into buildings is simply a no-brainer. If you have the ability to prevent falling snow loads, why wouldn’t you?
Assuming a mound of snow hanging precariously over a roof edge will probably fall AFTER you walk under it is living just a bit too much in the danger zone (cue Kenny Loggins). Protect the “danger zones”. Metal roofs are also often used for canopies at entrance/exit doors where pedestrians walk and vehicles load. These areas should be protected with snow guards, as well.
2. Limit Liability
If you own a business, an endless number of people walk in and out of your establishment daily. If a large amount of snow from your roof falls on someone, you could potentially be held liable.
Placing a few signs around a commercial property does not reduce your liability and holds little to no legal weight (or snow for that matter). Sure, the snow hasn’t fallen yet, but can you guarantee it won’t fall when an unsuspecting individual walks below?
Best practices for cold climate building design dictate that you should orient the roof in such a way that the snow is diverted away from passersby, but realistically speaking people will walk where they will. You must be aware of unprotected roof overhangs.
3. Protect Vehicles, Equipment, and Landscaping
Snow guards help protect vehicles and equipment too. Snow might be fluffy and light when it falls, but once it piles up on the roof, gravity load of the snowbank increases – magnifying the weight that will land below.
As for landscaping, if the rooftop avalanche wasn’t a direct hit, once it is piled up down below, that same snow bank can continue to cause additional troubles (e.g. creating the need to repeatedly remove snow; direct damage to building walls; indirect damage caused by funneling melt water into, rather than away, from the walls and foundations, etc.).
4. Protect Building and Roof Elements
Protect lower roofs from tons of snow crushing it below. Rooftop avalanches can shatter windows, rip off gutters, tear away siding, demolish vents, flatten seams, and buckle panels. They can even infiltrate the roof membrane allowing water to infiltrate the panels, exposing them to corrosion and degradation.
5. Reduce Maintenance Costs
Preserve the integrity of your metal roof by preventing careless damage or wear and tear that the roof was never designed to handle or support. The Metal Construction Association’s (MCA) technical document, Qualifying Snow Retention Systems for Metal Roofing, stresses the importance of a properly engineered roof and snow guard system.
Calculating the force of the snow for a specific area where the snow guards will be applied is the first step in installing a snow retention system. This calculation will restrain and engineer the strength of the system accurately for a unique set of specific variables. The right snow retention system will help spread snow loads across roof panels, holding snow build-up in place, until it slowly evacuates the roof by thaw and evaporation.
Snow Guards – Not Just for the Arctic Tundra
Whether you are living in a snowy climate or not, constructing residential or commercial properties, installing a new roof, or retrofitting an old building, metal is consistently the best choice for roofing.
Boasting versatility, durability, and sustainability, a standing seam metal roof may last well over 40 years. There is a common misconception that snow retention is only necessary in places with extreme amounts of snow. Take a look for yourself, the video below shows small and large amounts of snow cascading off of a slippery roof.
Metal is not the only roof style susceptible to a rooftop avalanche. A rooftop avalanche can occur on any type of roof. However, the more slippery the roof surface—the more likely the avalanche. That is why you should install an engineered snow retention system - to help mitigate this occurrence and limit potential liabilities caused by falling snow.