5 Ways Toronto’s Winter Weather Affects Your Roof

5 Ways Winter Weather Affects Your Roof in Toronto

Is your commercial flat roof ready for Toronto’s winter weather? Regular roof inspections and ongoing preventive maintenance will save your investment and reduce costly repairs, especially now that the cold weather is on its way. If your building has a flat roof, as most commercial and industrial buildings do, you may be aware that flat roofs are susceptible to damage from snow and ice.

Continuous exposure to cold, snow, and ice can create issues that can harm the entire building and the safety of employees and customers alike. 

1. Winter Weather Roof Challenges: Snow 

Large volumes of snow can create dangerous stress on a roof and can force water inside the roof assembly, causing internal leaks. Heavy snow can also compress the insulation, bear down on the deck, weaken building supports, and affect overall structural integrity, especially over the passage of time. A sagging roof can, in extreme situations, even lead to structural failure.

5 Ways Winter Weather in Toronto Affects Your Roof

Melting snow can also cause other problems. Water from melting snow can reach elevations on your roof that don’t typically get moisture from rain storms. Snow can also cause leaks at penetrations that are not tightly sealed, including HVAC unit access panels, vents, ducts, skylights and windows, and doors that face onto roof areas. To reduce the likelihood of problems from melting snow, clear all drains before the onset of winter, especially from falling autumn leaves.

5 Ways Winter Weather in Toronto Affects Your Roof

The accumulation of snow on a flat roof can impact service access, including walkways, to mechanical equipment, generators, solar PV systems, rooftop cellular equipment, and other roof elements.

2.Winter Weather Roof Challenges: High Winds

Metal copings, HVAC unit access panels, debris left on the roof, and skylights can be a concern in high wind storms if they aren’t securely fastened or if the roof isn’t kept clean. Wind can also cause snow piles to form and create heavy drifts, increasing stress and the chance of leaks at roof penetrations.

3.Winter Weather Roof Challenges: Freeze-Thaw Cycle

Warm days and cold nights create a freeze-thaw cycle, where roof materials repeatedly contract and expand. Without a positive slope to encourage drainage, melted snow can also cause ponding on a flat roof. While some water will drain as intended and naturally evaporate, the rest can refreeze, starting the freeze-thaw cycle.

One of winter’s main roof hazards, this cycle can cause cracks, shrinkage, and stress on the roof’s membrane. Other rooftop equipment–such as HVAC units, skylights, walkways, and railings–can also face potential damage.

5 Ways Winter Weather in Toronto Affects Your Roof

While modern roofing membranes are strong and can resist damage, constant strain from contraction and expansion eventually causes the weakening of BUR plies and PVC membranes. This loss of tensile strength can even cause PVC membranes to shatter when they near the end of their lifespan. In metal roofs, snow and ice can seep into seams that are opened up by the freeze/thaw cycle.  

4. Winter Weather Roof Challenges: Moisture and Condensation 

Condensation can occur inside your building when warm interior air rises and meets the colder underside of the roof–especially without proper ventilation. The likelihood is increased if the roof’s drainage passages are blocked or if the membrane is damaged. Resulting mold and mildew can cause condensation to collect in the seams in the deck substrate or on the underside of the roof assembly, causing water damage inside the building.

5: Winter Weather Roof Challenges: Ice Dams and Icicles

Ice dams happen when melting snow has formed around a blocked downspout or gutter. They can eventually damage the roofing membrane, lead to leaks inside your building, pull down gutters, and ruin insulation, flooring, interior ceilings, and walls.

5 Ways Toronto's Winter Weather Affects Your Roof

Ice dams can also cause ice to re-freeze on the side of a building where melting snow has created a buildup and overflowed, causing dangerously large icicles that can harm employees, customers, or pedestrian traffic.

Signs That Your Commercial Flat Roof Needs Attention

Winter weather hazards are a reality in the Toronto area, and it’s important to keep up with inspections and preventive maintenance. It’s time to contact your roofing specialist when you see these signs of damage that could lead to an even bigger problem:  

  • Evidence of leaks, cracks, or discolored spots on your ceiling  
  • Bowing of roofs, walls, or beams 
  • Difficulty opening doors
  • Extreme Icicles 

Reduce Commercial Flat Roof Damage This Winter

Remember, a small leak will only get worse in the cold weather! The best way to extend your roof’s lifespan and avoid costly roof replacement is to have routine roof maintenance, regular inspections, and ongoing preventative maintenance. 

To create a plan for protecting your roof year-round, work with a roofing contractor you can trust to provide high-quality work and second-to-none customer service. Contact Elite Roofing in Toronto this fall to protect your property investment against damage this winter.