Metal roofing panels come in two families. Exposed-fastener panels are screwed straight through their face into the roof. Standing seam panels hide the fasteners under a raised seam. On a house that carries snow for a good part of the winter, the choice that matters most sits inside the second family: how the seam closes and how the panel is held down. Colour and brand come after that.
Two families, and how to tell them apart
Stand back from the roof and look for screw heads.
Exposed-fastener panels are wide ribbed sheets fastened directly through the surface. Englert, a panel maker, describes the screws as “often equipped with washers” that “remain visible once the installation is complete.” They cost less and go on quickly, and the same maker lists barns, sheds, garages and outbuildings as their common home. Every one of those screws is a hole through the roof, sealed by a rubber washer that ages in the sun.
Standing seam panels run from the eave up to the ridge, with a raised seam at each edge where one panel locks to the next. The fasteners sit under that seam, out of the weather. Englert puts the seams “typically between 12 to 24 inches apart”, which is why a standing seam roof reads as long, clean lines.
A third product often gets filed with panels: steel shingles, which are stamped pieces that interlock to look like a shingled roof. They are a separate system with their own fastening, and they come up again below.
Three ways a standing seam closes
“Standing seam” covers more than one product. The panel maker Sheffield Metals splits it into three profiles, and they do not behave the same way under snow.
| Seam type | How the panel is held | What the maker says about it |
|---|---|---|
| Nail strip (fastener flange) | Screwed through a flange on one edge, then the next panel snaps over and hides the screws. No clips. | The lowest-cost standing seam. Not suited to regions with “significant snowfall/precipitation”. Panels follow any dip in the deck. |
| Snap-lock | Hidden clips screwed to the deck, then the panels snap together over them. | Mid-priced, no seaming tool needed. Generally not for slopes of 3/12 or lower. |
| Mechanically seamed | Hidden clips, then a seaming tool folds the two edges together, once (single lock) or twice (double lock). | The highest-cost profile. Double lock suits cold places with freezing and thawing. |
Sheffield also warns that freezing and thawing snow and ice work the metal and “could potentially disengage a snap-lock or fastener flange profile.” That is the point where a cheaper panel stops being cheaper. Around Collingwood and The Blue Mountains, snow sits on the roof, melts at the eaves on a sunny afternoon and freezes again at night, all winter.
None of this makes snap-lock a bad roof. It makes the seam a line on the quote that deserves a name, not a line that reads “standing seam, colour to be chosen.”
Long panels have to move
A steel panel grows in the sun and shrinks in the cold. On a short garage roof that barely registers. On a long run from a chalet ridge down to the eave, it adds up every day.
Sheffield’s rule of thumb is that panels over 25 feet should use clips that allow for thermal movement, and it notes that a nail strip panel, pinned straight to the deck, has no clips at all. If the rafters on your house are long, ask which clips hold the panels and which of them let the panel slide.
Steep chalet pitches help with water but not with this: the panel still moves, whatever the slope.
Low sections change the answer
Many houses here have a main roof steep enough for any panel, plus a porch roof, a dormer or an addition that is much flatter. Sheffield rates snap-lock and nail strip panels for steep roofs where water runs off quickly, and names mechanically seamed panels for low slopes. So the flat sections may need a different seam from the rest of the house, or a different roof altogether. A quote that prices the whole house in one panel type should say how it handles those sections.
Where steel shingles fit
Steel shingles solve a different problem: the look. On a street of older homes, a standing seam roof can read as modern or agricultural, and a steel shingle profile reads as traditional from the sidewalk. They carry their own fastening system and their own details, and they are priced below standing seam. Steel shingle systems typically start around $18,000 for an average home.
We install two systems on houses, standing seam and steel shingles, and our page on metal roofing in Collingwood sets them side by side. If you are still deciding between metal and asphalt at all, the numbers are in our long-run comparison of metal vs asphalt.
Four lines to find on the quote
Before you compare two metal quotes, check that each one names:
- The panel family: standing seam, steel shingle, or exposed fastener.
- The seam: nail strip, snap-lock, or mechanically seamed, and single or double lock if it is the last.
- The clips: which ones are fixed and which let the panel move.
- The low sections: what goes on any part of the roof flatter than the main slopes.
For everything else on the page, see how to read a roofing quote.
Two quotes that name different answers here are not the same roof, even at the same colour. Compare them against the roof replacement cost in Ontario ranges, not against each other alone.
A smooth metal roof sheds snow, and that changes the ice damming picture on Collingwood roofs. The eaves still need their membrane underneath.
Questions homeowners ask
Are exposed-fastener panels a mistake on a house? Not a mistake, but a trade. They are cheaper and quick to put on, and every fastener is a washer you will check and eventually replace. On homes, Englert lists garages, utility sheds and outbuildings as their usual place.
Is double lock always needed? No. It folds the seam twice, and Sheffield names it for cold places with freezing and thawing. On a steep main roof, a single-lock or snap-lock panel can be the sound choice. Ask the installer why they picked the seam they quoted.
Can I tell the seam type from the ground? Sometimes. A snap-lock seam tends to look broad and boxy. A double-lock seam looks folded over. The quote is the reliable answer, so ask for the product name and the profile.
Get both systems priced
We price standing seam and steel shingles on one visit, so you can compare the two like for like. Send us your roof details or call (249) 499-0101.