Is roof snow removal really necessary?

Every winter, snow accumulates on the roofs of Quebec homes and buildings. Some owners have their roofs cleared as soon as the first snow falls, while others wait. This question comes up every year: is roof snow removal really necessary?

The answer depends on several factors: the type of building, the amount of snow, the roof structure and the weather conditions. Poorly planned snow removal can be pointless, but waiting too long can put your building at risk.

This article explains when snow removal becomes essential and how to make the right decision to protect your property.

Things to remember

• Roof snow removal is not always necessary, but becomes essential in certain situations.
• The accumulation of wet snow, ice or overloads represents a risk to the structure.
• Flat-roofed buildings, plexes and older roofs are more vulnerable
• Watching for signs of subsidence allows you to take action before a serious problem occurs

Why snow on the roof can be a problem

Fresh, light snow is not usually a problem. A well-designed roof can support a certain amount of snow without risk. The danger arises when several factors accumulate: wet snow, freezing rain, freeze-thaw cycles or prolonged accumulation.

Each type of snow has a different weight. Fresh, powdery snow is much lighter than wet snow or ice. A roof that can withstand several centimetres of fresh snow may collapse under a shallower layer of wet snow, because it is considerably heavier.

The main risks are :

• Structural overload: the weight exceeds the roof’s capacity, causing subsidence or collapse.
• Formation of ice dams: meltwater accumulates and seeps under shingles
• Damage to flashings and joints: snow pressure forces water into the building
• Water infiltration: melting and refreezing create cracks and leaks

According to the Régie du bâtiment du Québec, roofs must be designed to support a specific snow load depending on the region, but excessive accumulation can exceed this capacity.

When snow removal becomes a necessity

Signs of sagging or overloading

If you notice any of these signs, snow removal becomes urgent:

• Doors or windows that jam or don’t close properly
• New cracks in walls or ceilings
• Unusual creaks from the structure
• Visible sagging of the roof from the outside

These signs indicate that the structure is under excessive pressure. Prompt snow removal can prevent major damage or partial collapse.

Accumulation of over 60 cm of snow

A general rule of thumb is that an accumulation of 60 cm or more of snow requires increased surveillance. If the snow is wet or mixed with ice, snow removal becomes necessary even at 30 to 40 cm.

Owners of plexes and commercial buildings need to be particularly vigilant. The larger surface area of these roofs increases the total weight of snow and the risk of subsidence.

Flat or low-slope roofs

Flat roofs retain more snow and meltwater. Unlike sloping roofs, where snow slides off naturally, flat roofs accumulate all the weight without natural drainage.

Clearing snow from a flat roof becomes essential as soon as a heavy accumulation forms, or rain is forecast after a snowfall.

Repeated freeze-thaw cycles

When snow melts during the day and refreezes at night, it turns into compact ice. This ice is much heavier than fresh snow and forms dams that prevent water from draining properly.

If you see ice on your roof or significant stalactites, snow removal is essential to prevent water infiltration.

Summary table: when to act

What you need to do to protect your roof

Check your roof regularly

After every storm, visually inspect your roof from the ground or a window. Note the snow depth, the presence of ice and any changes in the building’s appearance.

If you can’t see your roof, keep an eye out for signs inside: sticking doors, new cracks or unusual noises.

Call in the professionals

Clearing snow from the roof can be dangerous. There is a real risk of falling, slipping or damaging the roof. Calling in a specialized company guarantees a safe and efficient job.

The professionals know how much snow to remove without weakening the insulation or damaging the covering.

Prioritize certain areas

If complete snow clearance is not immediately possible, start with the areas at risk: around chimneys, vents and roof edges where ice dams form.

Clearing drains and gutters allows meltwater to run off properly and reduces the risk of infiltration.

Best practices to avoid problems

Preventive maintenance reduces the risks associated with snow accumulation. Here are a few habits to adopt:

• Have your roof inspected in the fall to identify any weaknesses
• Ensure adequate insulation and ventilation to prevent premature melting
• Install heating cables in the gutters if you have recurring ice problems.
• Consult a structural engineer if your building is old or if you have doubts about its capacity.

The Société d’habitation du Québec recommends that rental building owners set aside an annual budget for snow removal and winter maintenance.

What you need to know to protect your building

Roofsnow removal isn’t always necessary, but it does become essential under certain conditions. Monitoring snow accumulation, signs of sagging and weather conditions allows you to make the right decision at the right time.

Preventive snow removal always costs less than structural repairs or damage caused by water ingress. Investing in monitoring and maintenance protects your property and extends the life of your roof.

Need professional roof snow removal?

If you notice heavy snow accumulation or signs of overloading, contact Toiture Couvreur Laval for safe, efficient snow removal. Our team will quickly assess the situation and take action to protect your building.

Frequently asked questions