Snow buildup on rooftops could pose serious issues

FILE - Clearing the heavy snow off a roof in Gravenhurst, Ont. (CTV News/Rob Cooper)

As Mother Nature continues to blanket the region in the wintry white stuff, with no end in sight, the weight of accumulated snow and ice could be putting pressure on rooftops.

Excessive snow buildup has the potential to cause structural damage, especially after heavy snowfall or repeated freeze-thaw cycles.

How Much Can Snow Weigh?

The weight of snow depends on its type and condition.

Fresh, dry snow could weigh about seven pounds per cubic foot, but old, compacted snow can weigh up to 30 pounds per cubic foot, according to the Ministry of Labour, Training and Skills Development.

Addtionally, rain-soaked snow is significantly heavier and could increase the risk of collapse, while drifting snow can create excessive loads in various areas, such as against a wall or between roof levels.

The County of Simcoe recommends having snow removed from rooftops once it piles up beyond two to three feet, or 60 to 90 centimetres, to prevent structural issues.

Safe Removal

Clearing snow from a roof must be done carefully.

The County advises using a roof rake for safe removal, but says it’s best to call in a pro for tall or complex rooftops.

Homes with a steep roof, multiple stories, or excessive ice buildup, should have a professional tackle the removal as the safest option. A roofing or snow removal expert has the equipment to clear snow without causing damage or personal injury.

The ministry suggests taking several precautions, including assessing the roof to see if there are visible signs of structural distress, cracking, bending or twisting.

Snow should be removed gradually and evenly to avoid placing uneven pressure on the structure.

“It should also be remembered that workers on a roof must have adequate fall protection and that workers and others nearby can be injured by snow being dumped from a roof,” the ministry noted.

Consult a Structural Engineer

A civil or structural engineer should be consulted in cases where the snow load appears excessive, the roof shows signs of stress, or if reinforcements are required to support an overstressed roof.

Regular snow removal and proper safety measures can help to prevent costly damage and ensure safety.