How to prevent the roof of your business from collapsing

Last updated on January 30th, 2023

Winter weather puts roofs—including those on commercial buildings—to the test. Having a good business insurance policy will give you some peace of mind as a business owner, but prevention is the key to reducing the risks of roof collapse. But what exactly are the risks? How do you clear snow off your roof safely? And what are the warning signs? We’re there to answer these three important questions!


Snow on commercial buildings shouldn’t be taken lightly. The heavy snowfall we see in Québec every winter poses a threat to residential roofs but also to office, industrial, and commercial building roofs. Unfortunate roof incidents can also damage property and equipment. Not only that, but if the roof of your business were to suddenly collapse, it could pose a serious danger to your employees, customers, and anyone else on the premises.

That’s why it’s important not to underestimate the risks and make sure you know exactly what they are.

The amount of snow isn’t the only factor

When it comes to the dangers of accumulation, we assume (and rightly so) the biggest factor is the amount of snowfall. But it’s not just a question of volume; there are actually a number of factors at play. Changes in temperature and weather conditions (extreme cold followed by snow, thaw, rain, ice, and more snow) can cause a heavy mixture of snow and ice to build up on the roof.

And you can’t accurately assess the threat just by looking at how much snow has built up because the weight of snow can vary considerably depending on how dense it is. Consider this: One cubic metre of wet snow can weigh five times more than one cubic metre of fresh snow, and if it’s icy, it can weigh even more! Heavy snow is also less likely to get blown off the roof by the wind, so it tends to keep building up and building up....

Avoid major renovations!

While it’s true that infrastructure in Québec is designed to withstand winter’s whims, be careful not to do any renovation work that could potentially compromise the roof of your business. Before taking out a wall, putting on an addition, or enlarging the windows, talk to a structural engineer to make sure your plans are risk-free.

Flat roofs aren’t the only ones at risk

Did you think only flat roofs were a problem? Think again! Wind can cause snow to build up against prominent architectural elements, like chimneys. This can also happen with multi-tiered roofs or roofs separated by a vertical wall. And even the sun can play a role, causing a weight imbalance that can put a lot of pressure on a roof with two symmetrical gables, for example. Snow build-up on asymmetrical roofs is also something to consider. Basically, the risks are real and prevention is key, no matter what kind of roof you have.


The best thing you can do to keep the roof of your business from collapsing is obviously to keep it clear of snow and ice, and to do so regularly to prevent build-up. Whether you’re clearing snow from a commercial or residential roof, play it safe. The website of Commission des normes, de l’équité, de la santé et de la sécurité du travail has some very helpful videos (in French) that explain how to remove snow from a flat roof, for example. Follow these safety tips:

  • Plan snow removal with everyone’s safety in mind.
  • If clearing from the roof, have the proper equipment to prevent falls, injuries, frostbite, etc.
  • Create a safety perimeter around the building so that snow being cleared off can’t fall on someone below.
  • Ideally, do this operation from the ground. For sloped roofs, use a telescopic rake designed for this purpose, e.g., the SnowPeeler roof rake.
  • When clearing snow, be careful not to let it pile up temporarily anywhere on the roof. Don’t create even more risks!

For safety and efficiency, consider leaving the job to a qualified roof snow removal company.


How do you know when it’s time to clear the snow off your roof? Here are some warning signs of roof collapse to watch for:

  • Roof buckling
  • Warped or sagging ceilings
  • Cracked or warped walls
  • Doors that are harder to open and close or don’t line up
  • Unusual cracking noises

Pay extra close attention after severe weather or when a wintry mix leads to snow and ice accumulation. If you see any troubling signs, you might be better off evacuating the premises and removing any equipment that could be damaged. An annual preventive roof inspection by a qualified contractor is also well worth the money.

Now that you’ve got the answers to these three key questions, you may have a fourth: Is roof collapse covered by business insurance? The answer is: If you have comprehensive insurance, damage caused by the weight of snow or ice is normally covered. Take time to talk to your representative to make sure you have the insurance that meets your needs and line of business. At Promutuel Insurance, our agents and prevention advisors are there to help protect everything you’ve worked so hard to build!