Wood is the traditional pergola material, and a freshly oiled hardwood frame is genuinely beautiful — nobody argues otherwise. But a pergola lives outside through every storm, frost and heatwave, without a roof over its own head. So the fair comparison is not how the two materials look on delivery day; it is how they look, work and cost after five cold winters. On that timescale the gap opens fast, and this article walks through exactly where.
Maintenance: the biggest difference by far
Wood is a living material, and outdoors it never stops living. To keep an outdoor wooden structure looking like the photo, you sign up for a permanent cycle:
- Every year: cleaning off algae and grey film, especially on the weather side and horizontal surfaces where water lingers.
- Every one to two years: sanding back the weathered surface and re-applying stain or oil — on every beam, post and slat, including the awkward tops you can't see but the rain can.
- Ongoing: watching for cracks that open as the wood works, and for the first soft spots at end-grain and joints, where moisture gets in fastest.
Skip a season in a wet maritime climate and the process accelerates visibly: green algae by autumn, grey patina by spring, hairline checks widening in summer. None of this means the wood immediately fails — it means the structure demands a weekend of your time every year, forever, just to stand still.
Powder-coated aluminum removes the entire cycle. The coating is applied electrostatically and baked onto the metal in a factory oven — it is chemically bonded, not brushed on. Rain beads off it, UV does not chalk it, and algae find nothing to grip. The complete maintenance schedule for an aluminum pergola is: rinse it occasionally with water. There is nothing to sand, nothing to seal, nothing to repaint, ever. Ten years in, the frame looks like year one.
The louvered roof settles the argument on its own
Even if you love wood enough to accept the upkeep, there is a structural reason every serious louvered pergola on the market is aluminum: the roof is a machine.
A louvered roof is dozens of slats rotating together on a shared mechanism, sealing against each other when closed. For the seal to hold and the motion to stay smooth for thousands of cycles, the slats must keep their exact dimensions through humidity swings and temperature extremes. Aluminum does — it simply does not care whether the air is bone dry or saturated. Wood expands and contracts with every weather front. On a fixed roof that's tolerable; on interlocking moving parts it means binding in wet weather, gaps in dry weather, and a mechanism fighting its own material. This is why the choice was never really wood vs. aluminum for louvered systems — it is aluminum, or no louvers.
Strength you can put a number on
Modern aluminum systems are engineered to published ratings, not estimates. Our pergolas are rated for wind speeds up to 110 km/h — Beaufort 11, a violent storm — on a 13.5 × 13.5 cm post profile with 2 mm walls. The louvered roofs carry snow loads from 65 kg/m² on the manual Piano up to 320 kg/m² on the larger-rated electric sizes, with the exact per-size table published on each product page.
Comparable certified numbers are rare in wooden garden structures, and for an honest reason: timber quality varies from beam to beam, knot to knot. A C24 beam is graded, but a garden pergola assembled from mixed stock has no system rating. With engineered aluminum, the rating belongs to the whole structure — posts, connectors, roof and anchoring as one tested system. If your city or county or insurer ever asks what exactly is standing in your garden, that documentation exists.
Weight, foundations and installation
Aluminum's strength-to-weight ratio pays off before the pergola is even standing. The profiles are light enough for two or three people to assemble without lifting equipment — the manual Piano typically goes up in 3 to 5 hours — and the point loads on your terrace are modest. A hardwood structure of equal span is dramatically heavier: harder to handle, harder on the foundation, and usually a job for professionals with the invoices to match. Details on surfaces and anchoring are in our installation guide, but the short version: a solid terrace or concrete base that would sigh under hardwood carries aluminum easily.
Appearance: warmth is a design choice, not a material
The honest advantage of wood is warmth of appearance — but it is worth separating the warmth of a terrace from the material of its frame. A pergola frame is a few slim lines in the composition; what makes the space feel warm is everything inside it: furniture, planting, textiles, light.
In practice, an anthracite (RAL 7016) frame reads as modern architecture against greenery, and a white (RAL 9010) frame keeps a garden light and Mediterranean; both come alive with warm-toned furniture and soft planting around the posts. Add the warm 3000 K glow of integrated LED in the evening and nobody at the table is thinking about the frame material. And unlike stained wood, the color you choose is the color you keep — powder coating does not fade toward grey.
Sustainability, honestly weighed
Wood's renewable origin is a real point in its favour — but the full lifecycle deserves a look. Outdoor timber is treated, coated every other year with products that wash and wear into the garden, and replaced when rot wins. Aluminum asks more energy up front and then closes the loop: it recycles endlessly without quality loss, sheds no coatings into the soil, and a frame that stands for decades amortises its footprint across a generation of use. There is no perfectly green building product, but "buy once, maintain with water, recycle at end of life" is a defensible story.
The ten-year bill
Price is where wood's advantage is largest on day one and smallest on day 3,650. A rough, fair accounting for a mid-size pergola:
- Wood: lower purchase price + stain or oil every 1–2 years + your weekends (or a painter's invoices) + the odd replaced slat or beam + earlier full replacement if maintenance ever slips.
- Aluminum: higher purchase price + water.
Run the numbers over ten years and the totals cross well before halfway for most people — before counting what the maintenance weekends were worth to you, and before the resale reality that a maintenance-free terrace roof is a selling point while an ageing wooden one is a negotiation item.
The verdict
If you want a fixed, decorative frame for climbing plants and you enjoy woodworking as a hobby, wood remains a lovely choice. If you want an adjustable, waterproof, storm-rated roof that works every day for decades and never asks for a weekend back — the market settled this one: powder-coated aluminum, with a louvered roof on top.
See how our frames are built on the pergola overview, read how a louvered roof works, or request a free quote — approximate sizes are enough to start.