Solar carport wood or metal: honest 2026 comparison (lifespan, cost, structural)
Solar carport comparison wood (treated pine, larch, douglas fir) vs metal (aluminium 6063-T5, galvanised steel Z275): real lifespan, maintenance, structural loads, 25-year cost of ownership. Engineering team view, no sponsored content.
The choice between a wood and a metal solar carport goes far beyond aesthetics: it determines the lifespan of your installation, your buildings insurance coverage in case of storm damage, your ability to integrate an EV charger and your 25-year total cost of ownership. For equivalent surface area, the difference in life-cycle cost between the two materials can exceed £3,000 over the 25-year warranty period of modern PV modules.
This article compares the two material families with quantified data and no bias, from the engineering team’s point of view (BS EN 1991 loads, real durability, maintenance) and the buyer’s point of view (purchase price, total cost, EV integration). No sponsored content: Sunrak manufactures primarily in metal, but we cite the — real — cases where wood remains the right choice.
Wood and metal: what we actually compare
“Wood carport” covers three very different families:
- Pressure-treated pine class 4 — the majority of DIY/big-box “solar carport wood” kits (£1,800-£5,500). Lifespan 12-22 years with care; poorly suited to heavy PV roofs.
- Siberian larch or Douglas fir — premium timber prized in construction (£4,000-£9,000). 25-35 year durability, noble aesthetic.
- Glulam (glue-laminated) — for heavy framing or public canopies (£15,000-£50,000). Excellent performance but outside the residential range.
On the metal side:
- Aluminium 6063-T5 anodised — magnesium-silicon alloy, 15 µm anodising for corrosion resistance. Bespoke extruded profiles.
- Galvanised steel Z275 — sheet steel with 275 g/m² zinc coating (BS EN 10346). Cost-effective and very resistant inland.
Detailed comparison across 6 criteria
1. Real-world lifespan
| Material | Without maintenance | With regular maintenance |
|---|---|---|
| Pressure-treated pine class 4 | 12-18 years | 20-25 years |
| Larch / Douglas fir | 20-25 years | 30-40 years |
| Anodised aluminium 6063-T5 | 30-40 years | 40-50 years |
| Galvanised steel Z275 | 25-35 years (inland), 15-25 years (coastal) | 30-45 years |
Aluminium is the only material whose lifespan comfortably exceeds the 25-year warranty of modern PV modules. Practical consequence: replacing a wood structure mid-life of a PV installation requires dismantling the panels — additional cost £2,000-£3,500.
2. Structural loads under BS EN 1991
For a 2-car carport (6 × 5.5 m), 16 modules, in Snow zone Manchester area + Wind zone 25 m/s:
| Material | Required sections | Structure mass |
|---|---|---|
| Treated pine | Beams 120 × 240 mm + posts 180 × 180 mm | ~280 kg |
| Douglas fir | Beams 100 × 220 mm + posts 140 × 140 mm | ~210 kg |
| Aluminium 6063-T5 | Profiles 80 × 80 mm thickness 4 mm | ~95 kg |
| Galvanised steel | Profiles 80 × 60 mm thickness 3 mm | ~140 kg |
Aluminium is 3× lighter than treated wood for equivalent loads — drastically simplifying foundations and transport.
3. Maintenance
- Pressure-treated pine: oil/stain every 3-5 years (£160-£350 per pass), annual inspection of fastener corrosion
- Larch / Douglas natural: no maintenance if grey weathering is acceptable. Stain every 5-7 years (£280-£600) to preserve original tone
- Anodised aluminium: no structural maintenance. Annual pressure wash is enough
- Galvanised steel: no maintenance if Z275 coating intact. Touch-up paint on rust spots (rare inland)
Total 25-year maintenance cost: wood ≈ £1,100-£3,200, metal ≈ £0-£300.
4. EV charger integration
A 22 kW Wallbox draws 80 A at full power and needs a protected cable run, ideally integrated in the post. Aluminium: Sunrak extruded profiles include a cable channel in the section core, enabling invisible wiring. Steel: feasible with drilling and weatherproof gland. Wood: possible but needs external conduit or routing — aesthetically suboptimal.
5. Storm performance
UK insurer data after storms Eunice 2022 and Ciaran 2023:
- Wood carports: 40-60% of claims involve complete structural lift-off (under-sized foundations or anchorages).
- Metal carports designed to BS EN 1991: claims rare, mostly tree falls from neighbours, never own structural failure.
6. Total 20-year cost of ownership
| Item | Treated pine | Aluminium |
|---|---|---|
| Structure purchase | £4,200 | £10,500 |
| Installation | £1,200 | £1,200 |
| Stain (4 × £300) | £1,200 | £0 |
| Mid-life refurbishment at year 15 | £1,000 | £0 |
| 20-year total | £7,600 | £11,700 |
Aluminium remains more expensive overall — but over 25-30 years the balance flips: no replacement, no maintenance, while pine typically requires a heavy refurbishment at 20-22 years.
When wood remains the right choice
1. Listed area / conservation zone: if your works require approval from planning conservation officers (listed buildings, conservation areas), a wood carport may be obligatory for architectural integration.
2. Light load + mild climate: for a small 1-car carport with 4-6 modules in southern England, treated pine is sufficient with careful foundations.
3. Constrained budget: if the structure budget caps at £4,500 and the installation stays below 3 kWp, a well-installed wood kit is more pertinent than under-engineered metal.
In all other cases — 2+ car carports, EV charger integration, exposed climate, installation over 4 kWp — bespoke metal is the technically and economically superior option.
Final recommendations
| Your situation | Our recommendation |
|---|---|
| 1-car carport, < 3 kWp, mild climate, budget < £4,500 | Treated pine kit |
| 1-2 car carport, premium aesthetics, listed area | Bespoke Douglas fir |
| 2+ car carport, EV charger, exposed climate | Bespoke aluminium BS EN 1991 |
| Installation > 5 kWp, agricultural or commercial | Bespoke galvanised steel |
| Flat roof / canopy > 4 m height | Aluminium or steel — never wood |
FAQ — Solar carport wood or metal
Can a wood carport support solar panels?
Yes, provided sections are designed for real loads (modules + snow + wind). A generic "car carport" kit without PV preparation is typically under-engineered for this use. Always check the BS EN 1991 calculation report.
What is the real lifespan of a wood solar carport?
15-22 years for pressure-treated pine class 4 with stain every 3-5 years. 20-35 years for Douglas or larch. Beyond this, the structure becomes marginal — even though solar panels are still guaranteed 25-30 years.
Aluminium or galvanised steel: which to choose?
Anodised aluminium for exposed structures, coastal environments, exacting aesthetics. Galvanised steel Z275 for professional/agricultural structures inland, where strength/price ratio dominates.
Does my buildings insurance cover a wood carport?
Yes, in most cases. But after a storm-damage claim on a structure without BS EN 1991 documentation, the insurer can invoke "policyholder fault" (non-compliant construction). A documented calculation — as included in every Sunrak quote — secures the indemnity.
Is a wood carport always cheaper?
At purchase, yes (30-60% cheaper). Over 20 years with maintenance, the gap narrows to 20-30%. Over 25-30 years, wood often becomes more expensive if heavy refurbishment is included.
Which solution best integrates an EV charger?
Bespoke aluminium: our extruded profiles include a cable channel in the section core for invisible wiring. Wood needs external conduit or routing. Steel needs drilling + weatherproof gland — feasible but less aesthetic.
Which material is most recyclable at end-of-life?
Aluminium is 95% recyclable with only 5% of the energy of primary production. Galvanised steel is 90% recyclable. Pressure-treated wood is harder to recycle (often hazardous waste classification). Untreated Douglas/larch can be used as biomass.
Is 0% VAT eligibility different for wood vs metal?
For UK installations, 0% VAT applies to qualifying energy-saving materials regardless of the structure material, provided the structure is integral to the PV installation. The MCS-certified installer documentation is what matters, not the carport material itself.
Further reading: