For most residential balconies and rooftop decks, vinyl decking is the practical pick over aluminum. Aluminum plank systems (Duxxbak, LockDry, Wahoo Decks, AridDek) run $18 to $32 per square foot installed and get hot enough in direct summer sun to burn bare feet. Vinyl runs $12 to $22 per square foot installed, stays walkable, and has a much wider North American installer network. Aluminum earns its ask on a narrower set of projects.
I've spent twenty years installing vinyl deck membrane on balconies and rooftop patios, and every year a handful of homeowners come to me after cross-shopping aluminum decking. The reason is usually the same. They want a waterproof surface with the look of individual planks, and aluminum promises that. What they don't always price in is the surface temperature in July, the installer scarcity outside major metros, and the cost gap. Aluminum has real strengths and a real place, mostly on commercial rooftops and specialty residential projects. For a standard balcony or rooftop deck in North America, the practical answer is still vinyl. This guide walks through the tradeoffs where they actually matter. If you're also weighing composite or liquid membrane, my vinyl vs composite decking and vinyl vs liquid membrane guides cover those two.
How each system waterproofs
Vinyl decking is a continuous PVC membrane. Aluminum decking is an interlocking plank system with a waterproof channel or gasket between each board. Both create a waterproof deck. They do it in fundamentally different ways.
Vinyl comes off a roll, gets bonded to a plywood or concrete substrate, and gets heat-welded at every seam so the finished surface is a single sheet. The waterproofing is the surface itself. Whatever is under the deck stays dry because water has nowhere to enter. My seam welding vs adhesive guide covers how those seams are actually made.
Aluminum plank systems use extruded aluminum boards that lock into each other with an interlocking flange. The waterproofing lives in the joint between the planks, not on the surface. Water hits the boards, runs off via built-in slope, and any water that finds a seam is caught in a channel that drains to the edge. It's an assembly, not a membrane.
The distinction matters when something fails. On vinyl, a seam failure is fixed by a spot patch and a re-weld, and the substrate almost always stays dry because the failure is contained. On aluminum, a channel or gasket failure can leak into the wood or steel framing below without showing on the surface, and I've seen homeowners find water damage under a supposedly waterproof aluminum deck years after the leak started. Vinyl's failures are visible. Aluminum's often aren't.
Cost, side by side
Aluminum decking costs 40 to 80 percent more than vinyl on a like-for-like balcony project. Ranges I see across residential projects in North America:
- Vinyl decking: $12 to $22 per square foot installed
- Aluminum plank interlocking systems: $18 to $32 per square foot installed
Two things drive the aluminum premium. Extruded aluminum planks with a coating or PVC cap layer are more expensive to manufacture than PVC membrane on a roll. And because aluminum decking is a smaller category with a thinner installer base, the labour rate reflects that. Substrate prep is comparable for both, so the gap doesn't close on the plywood side.
Prep and repairs can shift these ranges further. For the full picture of what a vinyl install actually costs by region and project size, see my vinyl decking cost guide.
Heat: aluminum's biggest practical drawback
Aluminum decking in direct summer sun runs 20 to 30 degrees Celsius hotter than vinyl in the same conditions. Dark aluminum in July can top 80 °C (175 °F) at the surface, the point where a bare adult foot can only stand it for a second or two. Light-coloured aluminum runs cooler but still exceeds vinyl by a meaningful margin.
The physics is simple. Aluminum conducts heat roughly 1,500 times faster than PVC, so a metal deck absorbs solar radiation and passes it straight to the surface. Vinyl's PVC cap layer is a poor thermal conductor by comparison, so it holds surface temperature closer to ambient even on darker colours.
| Deck surface | Dark colour, full July sun | Light colour, full July sun |
|---|---|---|
| Vinyl decking | 60 to 70 °C | 45 to 55 °C |
| Aluminum decking | 80 to 95 °C | 55 to 70 °C |
Ambient outdoor temperature drives some of the spread, but the pattern holds across markets I've worked in. For a shaded balcony or a north-facing deck, aluminum's heat problem is minor. For a west or south-facing rooftop deck that catches full sun, aluminum is genuinely uncomfortable to walk on in bare feet from June through August. My does vinyl decking get hot guide covers the vinyl side of the same question in more detail, and even the darkest vinyl runs meaningfully cooler than aluminum in the same test conditions.
Lifespan and repair
Aluminum decking outlasts vinyl in theory and roughly matches it in practice. The metal itself doesn't UV-degrade, doesn't tear, and doesn't get punctured by dropped furniture. The coating on the metal does eventually chalk or fade, and the gaskets between the planks degrade in ways that are hard to see and expensive to fix.
Realistic service life on residential installs:
- Vinyl decking: 20 to 30 years, replaced as a full assembly when it fails
- Aluminum decking: 30 to 40 years for the metal itself, 10 to 15 years for the joint gaskets
Repair is where the practical experience diverges. A vinyl deck with a torn or seam-failed section gets patched or reskinned by any competent vinyl installer, usually for a few hundred to a couple thousand dollars depending on area. My repairing seam failure post walks through what that actually involves. An aluminum deck with a leaking joint has to be partially disassembled, which usually means pulling planks in sequence back from an edge until you reach the failure. Labour on that runs high, and finding an installer who can service the specific brand you have, ten years post-install, is genuinely difficult in secondary markets.
For what vinyl warranty terms actually cover on that repair side, see warranties explained.
Look and feel
The visual difference is easy to see. Vinyl gives you a continuous surface. Aluminum gives you the look of individual planks with visible seams. Which one is "better" comes down to taste, but there are practical implications either way.
Vinyl reads more like a floor. On a modern balcony where the deck is meant to blend into the exterior finish, that's usually what a homeowner wants. On a traditional wood-deck aesthetic, vinyl doesn't quite pass for planks even with wood-look patterns. My colours and patterns guide covers what the actual finish options look like.
Aluminum reads as a deck. Even with a woodgrain-embossed powder coating, aluminum planks look industrial from close up, and the visible joint every 6 or 8 inches is either a feature or a flaw depending on how you feel about it. On a commercial rooftop or a project where the plank look is the design intent, aluminum earns its ask. On a residential balcony where the goal is a clean waterproof surface, vinyl's continuous look is usually the easier fit.
Weight and structural fit
On a per-square-foot basis, vinyl deck membrane over its 3/8 inch plywood overlay lands around 1.5 to 2 pounds installed. Aluminum plank systems run 3 to 5 pounds per square foot depending on plank thickness and substructure. On a 200 square foot balcony, that's a difference of 300 to 700 pounds in total assembly weight.
Neither number is a structural problem on standard residential construction. Where it matters is retrofit projects on older balconies with tight structural margins, and rooftop decks where every pound of dead load has to be signed off by an engineer. On those, vinyl's weight advantage is real. On a new-build balcony designed around either system from the start, the weight question is a wash.
Installer availability across North America
Vinyl decking has a broad installer base across North America. Duradek alone lists over 840 certified dealers, and the four major vinyl brands (Tufdek, Valordek, and Dec-K-ing included) put well over 900 certified installers into the field combined. Aluminum decking, across every plank brand added together, has an installer base under 200 companies, concentrated in a handful of urban markets.
For a homeowner in Vancouver, Calgary, Seattle, Toronto, or a similar metro, both categories are available and comparable. For anyone outside a top-tier city, aluminum decking installers are hard to find and quotes are hard to get. Vinyl still has 40 to 100 dealers within an hour's drive of most North American population centres.
That gap widens on the service side. Warranty claims and repair work on aluminum decking, ten years after install, run into the same problem: the certified installer who did the job may not still be in business, and a replacement is harder to source than for vinyl. If you're going to own the deck for twenty years, the local installer base is worth thinking about now. My guide on finding a certified installer covers what to look for on the vinyl side.
When aluminum actually wins
Aluminum decking earns its ask on a few specific project types, and I'd tell a homeowner to price both when any of these apply:
- Commercial rooftops where longevity is prioritized over comfort and the deck sees shoes-on foot traffic year-round
- Projects where a plank look is non-negotiable and the homeowner has already ruled out composite because the balcony needs waterproofing
- Retrofits over existing steel joist framing where aluminum's compatibility with metal substructure is a real advantage
- Snow-country decks with heavy shovel use, where vinyl can be scratched by aggressive metal scraping and aluminum shrugs the same abuse off
For those situations, aluminum is a legitimate answer. For a standard residential balcony or rooftop with no special constraint, vinyl is the better practical pick nine times out of ten.
The comparison, on one screen
| Vinyl decking | Aluminum decking | |
|---|---|---|
| Waterproofing | Continuous PVC membrane, heat-welded seams | Interlocking planks, gasketed joints |
| Installed cost | $12 to $22 per sq ft | $18 to $32 per sq ft |
| Surface temp (dark, July sun) | 60 to 70 °C | 80 to 95 °C |
| Lifespan (structure) | 20 to 30 years | 30 to 40 years |
| Lifespan (joint gaskets) | Not applicable | 10 to 15 years |
| Look | Continuous, floor-like | Planks with visible joints |
| Weight | ~1.5 to 2 lb per sq ft | ~3 to 5 lb per sq ft |
| Installer base (NA) | 900+ certified | Under 200 |
| Repair | Spot patch or re-weld | Partial disassembly |
| Best fit | Most residential balconies and rooftop decks | Commercial rooftops and specialty projects |
Common questions
Is aluminum or vinyl decking better for a balcony?
Vinyl is the better pick for most residential balconies. It costs 40 to 80 percent less installed, stays cooler in direct sun, and has a much wider installer network across North America. Aluminum makes sense when the plank look is non-negotiable or when the deck is over a commercial space with heavy shoes-on foot traffic.
How much does aluminum decking cost compared to vinyl?
Aluminum plank decking runs $18 to $32 per square foot installed. Vinyl runs $12 to $22. That's a 40 to 80 percent premium for aluminum on a like-for-like balcony project, driven by higher material cost and thinner installer availability. Substrate prep costs are similar for both, so the gap doesn't narrow on the plywood side.
Does aluminum decking get hot in the sun?
Yes, uncomfortably so on dark finishes. A dark-coloured aluminum deck in full summer sun reaches 80 to 95 °C at the surface, hot enough that a bare foot can only stand it for a second or two. Vinyl in the same conditions runs 60 to 70 °C. Light-coloured aluminum runs cooler but still exceeds vinyl by 15 to 20 degrees.
Is aluminum decking waterproof?
Yes, but through a different mechanism than vinyl. Aluminum plank systems are waterproof at the joint, using an interlocking channel or gasket that drains water to the edge. Vinyl is waterproof at the surface via a continuous membrane. Both keep the substrate dry when installed correctly. Aluminum's failure mode is a hidden channel leak. Vinyl's is a visible surface tear.
How long does aluminum decking last compared to vinyl?
The aluminum itself lasts 30 to 40 years. The gaskets between planks typically need service in 10 to 15 years, and coatings can fade in 15 to 20. Vinyl decking lasts 20 to 30 years as a full assembly, replaced in one piece when it fails. Real-world lifespan is comparable once gasket maintenance is factored in on the aluminum side.
Can you install aluminum decking on a rooftop deck?
Yes, and it's one of the applications aluminum actually wins on. Structural strength, longer surface lifespan, and compatibility with steel joist framing make it a legitimate rooftop choice, especially for commercial projects. For a residential rooftop, vinyl is still usually the cheaper and easier install, but aluminum is a valid alternative if the plank look matters or the deck sees heavy foot traffic.
Bottom line
For a standard residential balcony or rooftop deck, install vinyl. It's cheaper, cooler in summer, easier to service locally, and easier to repair when something eventually needs attention. My scored reviews cover which vinyl brands earn the top marks, judged against the six criteria methodology I apply to every product on the site, and my choosing a vinyl deck membrane guide picks up from there if you've settled on vinyl and need to narrow to a brand.
If your project has a specific constraint that vinyl doesn't fit, a plank look that matters more than surface temperature, a commercial rooftop with heavy shoes-on traffic, or a retrofit over steel framing, aluminum decking is a legitimate alternative. Get quotes from both categories. Ask the aluminum installer about the gasket service interval and how a mid-run leak gets fixed. Ask the vinyl installer about the substrate prep detail. Those are the two line items most quotes underspecify, and they're where the twenty-year cost actually sits.