Metal Roofs
A metal roof is a genuinely good answer to a Toronto winter and it is not the answer to every Toronto roof.
Short answer
Metal sheds snow, resists ice damming better than asphalt, lasts decades longer, and costs substantially more up front. The real considerations are the snow-shedding behaviour over a door or a walkway, whether the deck and framing suit it, noise expectations, and finding an installer who does metal rather than one who will try.
What it does well here
Sheds snow rather than holding it, which reduces load and reduces the meltwater that feeds an ice dam.
Resists ice damming better than asphalt, because there are far fewer laps for water to get under — though it is not immune.
Lasts decades longer than asphalt, which changes the whole-life cost even at a higher install price.
Handles wind well when properly fastened.
Is light, which matters on an older roof structure.
And is available in profiles that look appropriate on Toronto housing, including standing seam and metal shingle, rather than only the agricultural profile people picture.
The snow-shedding problem
A metal roof releases its snow in a single slide, and whatever is below receives it: a doorway, a walkway, a driveway, a deck, the eavestrough, or the neighbour property. Snow guards or a snow retention system over those areas are part of the design rather than an afterthought, and a quote without them on a roof above a door is incomplete.
The honest limitations
Cost, which is substantially higher than asphalt up front.
Installer quality, which matters more than with shingles — a badly installed metal roof leaks at the fasteners and the seams and is difficult to put right.
Noise, which with a solid deck and underlayment is much less than people expect, and which over a cathedral ceiling with no deck is real.
Walkability, because working on a metal roof later — for a chimney, an antenna, a repair — needs care and the right footwear.
Expansion and contraction, which the system has to allow for and which is where cheap installations fail.
And appearance, which is a matter of taste and of neighbourhood character, and in a heritage area may be restricted.
Deciding
How long you intend to keep the house, because the economics favour metal over a long hold.
Whether the roof has repeated ice dam trouble, which is a strong argument for it — alongside fixing the attic, which still has to happen.
Whether there are doorways, walkways or decks below the slopes, which determines the snow retention design and adds cost.
Whether the roof is complex, because a cut-up roof with many penetrations is more difficult and more expensive in metal.
Whether there is a heritage or neighbourhood restriction.
And whether you can find an installer with real metal experience and references you can look at, which is the deciding practical question.
Common questions
Is a metal roof better for ice dams?
Considerably, because there are far fewer laps for water to get under. Not immune.
Is it noisy?
Over a solid deck with underlayment, much less than people expect. Over a cathedral ceiling with no deck, real.
Do I need snow guards?
Over any doorway, walkway, deck or driveway. It is part of the design.