Roof collapses feared if freezing rain follows heavy snowfall

Fearing a wave of roof collapses could occur in the short term, Toitures Hogue, a large Quebec roofer, is urging owners of commercial, industrial and/or institutional buildings to be cautious and proactive in advance of a freezing rain forecast over the next few days.

Coming after the province’s first heavy snowfall in 2024, the roofer’s warning observes the province suffered a large number of roof collapses in 2019. Toitures Hogue notes some insurance contracts do contain exclusions for damage to roofs caused by negligence. Commercial property owners may wish to contact their insurance providers to check their insurance coverage.

A snowfall warning was in effect for Montreal Saturday, with about 15 cm blanketing the city. The weight of the snow is predicted to become heavier because of freezing rain forecast over the next few days.

Toitures Hogue president Jocelyn Hogue issued a public comment Tuesday noting that for every square foot of roof, a depth of accumulated snow adds an additional weight of 56 pounds per cubic foot of snow to a roof’s load-bearing capacity — and 65 pounds when transformed into water.

“Such situations can be catastrophic for a building owner or manager,” Hogue said.

Related: Why the court found the landlord responsible for this winter roof collapse

In addition to legal issues, “major economic impacts could arise from the refusal of some insurers to pay financial compensation under insurance contracts, due to the negligence of owners and managers,” the company warned.

Building owners in these conditions could be exposed to civil lawsuits from building users whose safety could be compromised by a lack of preventive maintenance in the circumstances. “It’s vital to detect early the warning signs of a possible roof collapse, which can infallibly lead to major damage to an entire building,” Hogue said.

He noted early warning signs of a potential roof collapse include cracks in interior walls, interior doors that suddenly jam, creaking noises coming from all over the shell of a building, and even minor deformations of a ceiling.

Ice damming can also cause water damage to the property in these weather conditions, insurers have noted in the past.

An ice dam forms when a ridge of ice forms at the edge of a roof. The ice ridge prevents water caused by melting snow from draining off the roof. This water then backs up behind the dam, and can then leak into a residential or commercial building, causing water damage to walls, ceilings, insulation and other areas.

Feature image courtesy of iStock.com/AscentXmedia