A heavy snowfall drops 30 cm overnight and the whole day becomes clearing it. Wet and compacted snow is far heavier than the fresh dry stuff, and on a roof it adds up to tonnes. Getting it off the right way protects your back — and everyone underneath whatever you're clearing.
The hazard
Shovelling is hard, cold work that loads the back, shoulders, and heart. Plows and loaders have blind spots big enough to lose a person in. And snow piling on roofs, canopies, and scaffold planks puts weight on structures that may never have been rated for it — worse after rain or a melt-freeze, and worse again where it drifts into one area.
What to do
- Push rather than lift where you can. Warm up first, small loads, lift with your legs, no twisting. Switch sides and take breaks.
- Keep clear of plows and loaders, and don't rely on a look from the cab. Eye contact tells you the operator saw you a second ago — it isn't permission to walk in. Wait for a clear acknowledgement back, and for the machine to be stopped and secured, before you approach. Where the operator's view of the path is blocked, or anyone could be endangered, a signaller is required and that's their only job.
- Roof snow is an engineering job before it's a shovelling job. Where snow load may be significant or there's any sign of structural distress — twisting, bending, cracking — the roof gets assessed by a professional engineer, and the removal procedure comes from a civil or structural engineer so that taking the snow off doesn't cause its own failure. Follow that sequence.
- Prefer a method that keeps people off the roof entirely if the job can be done from the ground or mechanically. That's our judgement call rather than a rule, but a hazard nobody is standing in is the one that can't hurt anybody.
- If someone does go up: confirm the structure first, use the fall protection the plan calls for, know where the hidden skylights and openings are, and never send one person alone.
- Avoid uneven or concentrated loading while you clear — don't strip one area bare and leave the rest, and don't pile removed snow somewhere else on the same roof.
- Don't free-dump snow over the edge. Material isn't to fall freely from one level to another — it comes down by chute, in a container, or by crane or hoist. Where anything could fall on someone, there has to be overhead protection at the ways in and out and over work areas, and the area receiving the snow gets secured against access, not just roped and watched. Never near doorways, exits, or walkways.
- Pile snow where it won't block fire exits, hydrants, or sightlines at gates.
Watch out for
- Roofs, canopies, and temporary structures sagging or creaking, or doors that suddenly stick — get off and clear the area below.
- Cardiac warning signs while shovelling: chest pressure or pain, shortness of breath, nausea, feeling faint, or sweating that's out of proportion to the work. Heavy sweating on its own is just hard work in the cold — it's these together that matter. Stop, call 911, stay with them, and don't let them drive themselves anywhere.
- Hidden curbs, hoses, and equipment under fresh snow.
- Drifted areas carrying far more load than the flat parts of the same roof.
Talk it over
- Where's today's snow going — and is that spot clear of exits, hydrants, and foot traffic?
- If we're clearing a roof this week: who assessed it, whose removal sequence are we following, and how is the area below secured?