Metal roofing · Metro Vancouver & the Fraser Valley
Metal roofing in Metro Vancouver: the system we install, and what it does in this climate
We install one metal roof system: 26-gauge snap-lock standing seam panels over a high-temperature peel-and-stick underlayment. Concealed clips hold the panels, so nothing is screwed through the face of the roof, and the membrane underneath is rated for the heat that builds up beneath metal.
On a coast that rains for five months and grows moss on everything porous, those two choices — concealed fastening and the right underlayment — are most of what separates a metal roof that lasts from one that does not.
The system
26-gauge snap-lock over high-temperature peel-and-stick.
Metal roofing is not one product. It is at least three quite different families of product that share a material, and most of the confusion in metal roof quotes comes from comparing across families without noticing.
- Exposed-fastener panels. Corrugated or ribbed sheets screwed straight through the face, with a rubber washer under each screw head. Cheap, quick, and normal on agricultural and industrial buildings. Every screw is a hole through the waterproofing, and every washer is a component with a shorter life than the panel it is holding. We do not use them on houses.
- Snap-lock standing seam. Panels run unbroken from ridge to eave, their edges turned up to form a raised vertical seam that sits above the water plane. Hidden clips fasten to the deck and the next panel snaps over them. No fastener passes through the field of the roof. This is what we install.
- Mechanically seamed standing seam. The same concealed-clip idea, but the seam is folded closed on site with a seaming machine instead of snapping shut. Used mainly where the slope is lower than a snap-lock system is approved for.
26-gauge is the panel thickness, and on the gauge scale a lower number means thicker steel. It is the weight we use on residential metal roofing because it holds a flat, unrippled plane across a long panel and takes the handling of an installation without oil-canning the way thinner material does.
Underneath every panel goes a high-temperature peel-and-stick membrane across the full deck, not just at the eaves. That is the layer explained further down this page, and it is the part of a metal roof installation that you will never see and should always ask about.
The comparison people ask for
Standing seam metal roof against snap-lock: what the difference actually is.
This is the most common question we get about metal, and it starts from a false premise. Snap-lock is not an alternative to standing seam. Snap-lock is a standing seam profile. The real question is how the seam gets closed.
What they share
Both are concealed-fastener systems. In both, the panel edges stand up above the plane the water runs on — which is where the name comes from — and both are held to the deck by clips hidden inside the seam. In both, the panels are free to expand and contract along their length as the roof heats and cools, which is not a small detail on a black roof in August. From the street, on a normal house, they look the same.
Where they part
A snap-lock panel is engineered so the male edge of one panel clicks permanently over the female edge of the next by hand pressure. A mechanically seamed panel has a flatter, open profile that is folded over, once or twice, by a powered seaming machine driven along the length of the roof after the panels are set.
Why the folded seam exists
Slope. A snapped seam is a very good water barrier on a roof with enough pitch to move water off quickly. On a shallow roof, where water lingers and wind can drive it back up the slope, manufacturers require a double-locked seam instead, and they publish a minimum slope for each profile in the installation instructions. Below that number the system is not warranted, whatever the roofer says.
What that means for your house
On a normal pitched Lower Mainland roof — a gable, a hip, a cross-gable, anything you would have shingled — snap-lock is the right system and gives you the identical concealed-fastener construction with a simpler, faster installation. Where a roof is genuinely low-slope, metal is usually the wrong answer altogether and a membrane is the right one. That is the honest version, and it is why the flat section of a mixed roof gets two-ply SBS torch-on rather than panels.
The invisible layer
Why the underlayment under metal matters more here than anywhere.
If you take one thing from this page, take this one. The underlayment under a metal roof is not the same product as the underlayment under shingles, and substituting the cheaper one is the most common and least visible corner cut in metal roof installation.
Heat is the reason. The cavity between a metal panel and the deck runs far hotter than the equivalent space under an asphalt shingle, because the metal conducts solar heat straight through rather than absorbing it into a thick mat. Ordinary self-adhered membranes are asphalt-based. Asphalt softens. A membrane that softens at panel temperatures can creep, lose its seal around the clip fasteners, and in the worst cases bond itself to the underside of the metal so the panels cannot move as they expand.
Rain is the second reason. Between October and March a roof in this region is wet far more often than it is dry, and the underlayment is the layer that has to hold the line every time wind drives water up a seam, past a clip, or under a valley. On a shingle roof there is a thick mat above the membrane to slow that water down. On a metal roof there is a thin, smooth panel and a lot of capillary opportunity at every lap.
So we run high-temperature peel-and-stick across the whole deck, not a strip at the eaves and felt everywhere else. It is self-sealing around every clip fastener, it is rated for the temperatures metal actually reaches, and it means the roof has a genuine second waterproof layer rather than a symbolic one.
When you are comparing metal roofing quotes, this is the line to look for. Two quotes for the same 26-gauge panel can be a long way apart and the gap is often sitting in this one product. Ask each roofer to name the underlayment and confirm it is high-temperature rated. It is a thirty-second question that tells you a great deal.
Slope
Metal on low-slope roofs, and the mixed roofs we see most.
Every metal panel profile has a minimum slope published in the manufacturer's installation instructions, and it is not advisory. Install below it and the panel warranty does not apply, which makes the whole exercise expensive and unprotected at the same time.
Snap-lock needs meaningful pitch. Mechanically seamed profiles go lower. Neither one goes to the slopes we routinely see on garages, additions and mid-century flat roofs across Vancouver, Burnaby and the North Shore, which are often a quarter-inch to the foot or less. Those roofs need a fully bonded membrane, full stop.
This matters here more than in most markets because the mixed roof is so common: a pitched main roof with a flat section behind it over a kitchen addition, a carport, a laneway suite or a sun deck.
How we handle a mixed roof
- Metal on the pitched planes, at or above the profile's published minimum slope
- Two-ply SBS torch-on across the low-slope section
- Custom 26-gauge flashing at the transition, lapped so the membrane runs up under the metal rather than butting against it
- One crew doing both, so the transition is nobody's boundary and nobody's excuse
The junction between two roof systems is where mixed roofs leak, and it leaks most often when the two systems were installed by two trades on two different visits. Our flat roofing overview covers what happens on the low-slope half.
The attic
Condensation and ventilation under a metal roof.
Metal does not cause condensation. A badly ventilated attic causes condensation, and metal is simply better than shingles at showing you it is happening.
The mechanism is the same one that rots plywood under asphalt. Warm, humid air from showers, cooking and laundry rises into the attic. If there is not enough intake at the soffits and enough exhaust near the ridge, it stays there until it meets a cold surface and turns back into water. Under metal, the coldest surface on a clear winter night is the underside of the panel, and the drips that follow get read as a leaking roof.
The fix is not a different roof. It is the same ventilation work we do on every replacement: new vents sized to the roof at roughly one per five squares using Duraflo 50 vents, intake at the soffits actually open rather than stuffed with insulation, and bathroom and kitchen fans ducted through the roof or the wall instead of dumping into the attic. New plumbing and HVAC flashings go on at the same time.
There is one genuine metal-specific point. Because metal loses heat to a clear night sky quickly, an attic that was borderline under shingles can tip over the edge under panels. If your house already has damp attic air, frost on nail tips in January or matted insulation under the vents, that is worth correcting as part of the metal roof installation rather than discovering afterwards. We check it during the inspection and say so either way.
Myths
Noise, hail, lightning, and the rest of it.
"Metal roofs are loud in the rain"
The memory behind this is real and it comes from the wrong building. Bare corrugated sheet screwed to open purlins over a barn, a shed or a carport, with nothing between the metal and the air, is genuinely loud. A residential metal roof is a panel on a solid plywood deck, over a full-coverage peel-and-stick membrane, over insulation and a drywall ceiling. That assembly is not silent, but the difference against asphalt in a Lower Mainland downpour is small, and almost every owner stops registering it inside the first week.
"Hail will dent it"
Hail is not the local test. Metro Vancouver and the Fraser Valley get very little hail and almost none of the size that damages roofing. What our roofs get tested by is rain, wind and moss, and metal does well against all three. If you are moving here from Alberta, this is one of the few roofing worries you can genuinely set down.
"Metal attracts lightning"
It does not. Metal is a conductor, not an attractant, and a metal roof is non-combustible, which is the useful property in the rare event of a strike. The Metal Roofing Alliance publishes the technical position on this, along with the rest of the material-level data worth reading before you choose.
"You cannot walk on it"
You can, in the right places, in the right way. Panels are walked during installation and during service work. What you should not do is treat a metal roof as a casual surface for hanging Christmas lights or cleaning gutters, because the places that take weight safely are not obvious from up there and a dent in a panel is permanent in a way a dented shingle is not.
"It will rust"
Steel panels are coated on both faces, and the finish is what stands between the steel and the weather. Cut edges, drilled holes and abraded spots are where rust starts on a metal roof, which is another argument for a concealed-fastener system with no holes through the face and for flashings bent properly rather than cut and caulked.
Warranties
The finish warranty is the manufacturer's. The workmanship warranty is ours.
These are two separate documents covering two separate risks, and merging them into one number is the oldest trick in roofing sales. We do not do it, and you should be suspicious of anyone who does.
The manufacturer's warranty covers the panel and its coating: things like perforation of the substrate and the performance of the paint system against chalking and fading. It is issued by the company that made the steel and the finish, it runs on their terms and for their period, and those terms carry conditions — coastal exposure, compatible materials, correct installation, sometimes registration within a window. We register it in your name and hand you the document. What it covers is the product, not the roof.
Our workmanship warranty covers the installation: ten years on metal work, the same as our shingle, cedar and composite work. Torch-on and flat membrane work carries five years, which is the standard for flat systems. That warranty is about whether the flashings, clips, laps, penetrations and transitions were done correctly, which is where installed roofs actually fail.
The two never get added together. A roof is not protected for the sum of two unrelated numbers, and a metal roof with a long finish warranty and a badly flashed chimney will leak while the paint is still perfect.
Worth knowing: the finish warranty on coated steel usually has different terms within a set distance of salt water. If you are in West Vancouver, Tsawwassen, White Rock or anywhere on the shoreline, ask for the coastal terms specifically rather than the general ones.
Where we work
Residential metal roofing near you, from West Vancouver to Chilliwack.
Metal makes more sense in some parts of this region than others, and the reason is rainfall. Environment and Climate Change Canada's published climate normals put Richmond near 1,160 mm a year, Abbotsford around 1,505, Vancouver Harbour 1,537, Chilliwack Airport near 1,668 and the Capilano station in North Vancouver above 2,500.
On the wettest, shadiest lots — the North Shore, the slopes above Port Moody, parts of Maple Ridge and Mission — asphalt spends its life hosting moss and reaches the end of it sooner. Metal gives moss very little to grip and sheds needles rather than trapping them, and that is where the case for metal roofs is strongest. On a dry, exposed lot in Delta the argument is more about appearance and service life than survival.
We install metal roofs across Vancouver, Burnaby, Surrey, Richmond, Coquitlam, Port Coquitlam, Port Moody, North and West Vancouver, New Westminster, Langley, Delta, Tsawwassen, White Rock, Maple Ridge, Pitt Meadows, Abbotsford, Mission, Chilliwack and Anmore. We are WorkSafeBC registered, carry five million dollars of liability insurance, are GAF certified, and belong to the ICBA and the BBB.
Questions
Metal roofing, plainly answered.
What metal roofing system do you install?
A 26-gauge snap-lock standing seam system laid over a high-temperature peel-and-stick underlayment. The panels run from ridge to eave, lock to each other along raised vertical seams, and are held down by concealed clips, so there are no exposed screws through the face of the roof and nothing penetrating the waterproofing layer in the open field.
What is the difference between standing seam and snap-lock?
Snap-lock is a type of standing seam. Both are concealed-fastener systems where the panel edges stand up above the water plane and are held by hidden clips. The difference is how the seam is closed: a snap-lock panel clicks into its neighbour by hand, while a mechanically seamed panel is folded shut on site with a seaming machine. Mechanically seamed profiles are used mainly where the slope is too low for a snap-lock to be approved. On a normal pitched house, snap-lock gives the same appearance and the same concealed fastening.
Why does the underlayment under a metal roof matter so much?
Because the space under a metal panel gets far hotter than the space under a shingle, and many standard peel-and-stick membranes are not rated for it. An underlayment that softens at panel temperatures can flow, lose its seal around fasteners and stick to the underside of the metal. We use a high-temperature peel-and-stick made for this application, which is the single most common corner cut on cheap metal roof installations and completely invisible once the panels are on.
Is a metal roof noisier in the rain?
Not meaningfully, on a house. The noise people remember comes from bare metal fastened over open purlins in a barn or a shed, with nothing underneath it. A residential metal roof sits on a solid plywood deck over a peel-and-stick membrane with an insulated ceiling below, and the measured difference against asphalt in a rainstorm is small enough that most owners stop noticing it within a week.
Can metal go on a flat or low-slope roof?
Snap-lock cannot. Every snap-lock system carries a minimum slope in its published installation instructions, and below that slope the manufacturer will not warrant it, because water can be driven back up the seam. Very low slopes need either a mechanically seamed profile or a membrane. On the mixed roofs that are common here, we run metal on the pitched planes and two-ply SBS torch-on across the flat section behind them.
Do metal roofs cause condensation?
The metal does not cause it; a badly ventilated attic does, and metal makes it more obvious because the underside of a cold panel is an ideal surface for water to form on. The answer is the same as it is under shingles: enough intake at the soffits, enough exhaust near the ridge, and bathroom and kitchen fans ducted outside rather than into the attic. We size and replace the ventilation as part of the installation.
How long does a metal roof last in the Lower Mainland?
Longer than asphalt, which regionally runs about twenty-five years. Metal has no granules to lose and does not become brittle with ultraviolet exposure, so what eventually dates it is the paint finish and the condition of the details at penetrations, walls and valleys. Those details, not the panels, are what decide how a metal roof ages here.
Does moss grow on a metal roof?
Far less than on asphalt, and what does land on it tends to wash off rather than root. Moss needs something porous to grip; a coated metal panel gives it very little. On a shaded North Shore lot that is a real advantage, though overhanging branches will still drop needles into the valleys, and those still need clearing.
What warranty comes with a metal roof?
Ten years on our workmanship, the same as our shingle, cedar and composite work. The panel and finish warranty is an entirely separate document issued by the manufacturer on its own terms, covering things like perforation and paint performance, and registered in your name. The two are never combined into one headline number, because they cover different things and run for different lengths of time.
Will a metal roof attract lightning?
No. Metal does not make a strike more likely; it is a conductor, not an attractant, and a metal roof is non-combustible, which is the opposite of a hazard if a strike does occur. This is the most persistent myth about metal roofs and the easiest one to check against the Metal Roofing Alliance's published material.
Next
Find out what a metal roof would cost on your house.
Type your address and we measure the roof from satellite imagery, then price a 26-gauge snap-lock system against what is up there now, with the flat sections costed separately where your roof has them. The number is on the screen before we ask you for anything.