Watch out for snow accumulation on your roof

First of all, be vigilant. There are several signs to watch for that mean your roof is under too much pressure:

• cracks that appear and run along your interior walls
• doors that either open by themselves or stay stuck
• creaks that are loud enough to be heard

You might believe in supernatural phenomena, but it’s probably your roof that’s crying out for help. Best to listen to it before it collapses!

Weather conditions to watch out for

In winter, it’s not unusual for heavy snowfalls to be followed by a mild spell, some freezing rain, and then a deep freeze. This destructive cocktail promotes the formation of ice which, when combined with snow accumulation, prevents normal surface runoff and could cause water to seep in or even the building to collapse.

Evaluating the risks

Did you know that wet snow exerts more pressure than powdery snow? The thickness of the accumulation has to be taken into account, but so does the nature of the snow.

*Data based on the snow load of a flat roof built after 1980

The shape of the roof and its age are also important factors when it comes time to evaluate risk. Commercial buildings of 5,000 square feet or more (per floor) that are more than 10 years old are particularly at risk of collapsing.

Preventing collapse

Here are some rules to follow to minimize risk:

• Regularly inspect and clear drains, gutters and downspouts if debris or ice have accumulated inside, and remove the snow around them.
• Have your roof checked and repaired if necessary.
• Inspect the condition of your roof after major snowfalls.
• Clear the snow and ice from your roof on a regular basis.
• Call a building inspector if you have any concerns regarding possible structural damage.

Leave it to a pro

Don’t trust just anyone to remove the snow from your roof! It takes know-how and the proper equipment. Obviously, the best thing would be to remove the snow after every heavy snowfall, but it can be dangerous. What’s more, to avoid damaging the waterproofing membrane, you mustn’t remove all the snow from the roof. It would be wise to hire experts who are familiar with best practices and will do the job right.