Removing snow from the roofs of your commercial buildings

Canadian winters can be hard on the roofs of your commercial buildings. Snow, freezing rain and strong winds can damage them or even cause them to collapse. Protect the building’s occupants and avoid property damage by following our advice on when and how to remove snow.

What risks do you run if you don’t remove snow from your roof?

1. Falling snow and ice

If it warms up, accumulated snow and ice can break off and fall to the ground. This could injure passers-by. Emergency exits and access routes could get blocked, which would be a problem for employees and occupants. Even cars parked close by could be impacted!

2. Roof collapses

A big pile of snow or ice puts pressure on the structure, which can sometimes cause serious damage. If it collapses, the roof can cause injuries or even result in deaths.

3. Water seepage through the roof

When a large quantity of snow or ice melts, seepage could occur. If gutters or other drainage equipment are blocked, the water will find another path and could cause property damage.

How can you reduce these risks?

As a property owner, you are responsible for maintaining the security of your commercial buildings. There are several means available to you for eliminating the risks:

  • Clear snow safely.
  • Maintain the building all year round.
  • Keep emergency exits cleared at all times.

What is an acceptable weight for accumulations?

Roofs are generally designed to support a maximum of 50 pounds per square foot. Since ice is ten times heavier than snow, it could cause even more damage. Check if the accumulation is made up of snow or ice to determine if it’s time to act.

When should you prepare to clear snow from a roof?

When the weight reaches 30 pounds per square foot, take action to prevent a problem from developing. Letting things go to test the roof’s maximum capacity is running a big risk!

Not sure how to evaluate the weight of the snow? Let Domely look after it. This new technology monitors your roof. It warns you when it’s time to remove snow. Simple and affordable, it is recognized by certain insurance companies. 

How do you know if there is a risk that your roof may collapse?

Here are some warning signs indicating that you need to immediately remove accumulations:

  • Bulging roof
  • Deformities in the walls or ceilings
  • Cracks in the walls
  • Doors that are difficult to close
  • Cracking noises

If in doubt, contact a structural engineer. He or she can help determine if the building is in good condition or if it has been damaged.

Are certain buildings more susceptible to damage?

Yes, buildings with the following characteristics should be monitored more closely:

  • Flat roofs or those with a low slope or big surface area
  • Roofs more than 20 years old
  • Buildings more than 30 years old

If your building meets these descriptions, step up the precautionary maintenance.

What are the advantages of signing a snow removal contract at the beginning of the season?

A company that is specialized in this type of snow removal can safely do the work for you. These experts have the equipment, know-how and necessary insurance to perform the work. This way, you

  • Reduce the risk of damage to your roof and structure
  • Protect your buildings and your investment
  • Reduce the risks for passers-by and occupants
  • Save time, since you don’t need to remove the snow yourself and acquire the necessary safety equipment

Can you do the snow removal yourself?

Yes. However, be sure to follow provincial guidelines. Ensure that the area where snow and ice will fall is well-indicated. Use a security harness with a fall protection device.

In Quebec, the Commission de la santé et de la sécurité du travail (CNESST) sets out methods depending on whether the roof is flat or sloped. If you do the work yourself, be sure you are well-informed before starting.

A few other tips for removing snow from the roof of a building

Be sure to leave a thin layer of snow. This way, you won’t damage the waterproof lining. Check if snow or ice are in the roof space or on the plumbing.

Removing snow from the roof has to be on the list of any building owner who wants a well-maintained commercial building. You’ll get through this winter with peace of mind if you protect yourself against weather event risks.