Know load limit to reduce chance of roof collapse
New Brunswick homeowners and business are being reminded to exercise caution when removing snow from rooftops.
“Although snow removal can be dangerous, it’s something that must be done since not removing snow can be even more dangerous,” said Laragh Dooley, WorkSafeNB’s acting director of communications. “Snow loads can cause roof collapse and, if the roof is sloped, can fall onto pedestrians and vehicles below.”
Ensuring that loads don't accumulate is a requirement under New Brunswick's Occupational Health and Safety Act. To reduce the chance of a roof collapse, it’s important to know a roof’s load limit, which may require input from an engineer.
Since the greatest hazard faced in removing snow from roofs is the risk of falling, it’s important that employers provide, and employees continually use, a fall protection system. Employees need to be properly trained and educated on any hazards and risks; appropriate personal protective equipment (PPE) must be supplied and used; and drop areas shall be marked on the ground to prevent access, WorkSafeNB said.
If there are no knowledgeable and experienced employees to do the job, hire professionals.
Snow should be cleared in a cross direction to the roof trusses. This will reduce the stress on all the trusses at the same time, rather than reducing stress from only one truss. Drifted snow should be removed first. (On multi-level roofs, this will be on the lower roofs).
It’s important to remove snow evenly from both sides of the roof to avoid concentrating a load in one area, WorkSafeNB said. Failure to follow these steps could cause enough stress to the roof to cause it to collapse. If using mechanized equipment on the roof, ensure the employee is familiar with the manufacturers’ instructions for safe use and that it is not used within 15 feet of the roof edge (only allowed on roof with pitch of 3 in 12 or less).
WorkSafeNB cautions against using mechanized equipment that can damage the roof membrane. Since metal shovels and ice picks can also damage the roof membrane, use plastic instead.