Composite vs Timber Decking Cost in Perth

By the WTD team · Updated June 2026

Composite and hardwood timber land at almost the same price to build in Perth — the real difference shows up over ten years, not on the first invoice. Here's how the two compare on upfront cost, ongoing maintenance and lifetime spend for a WA deck.

It's the question nearly every Perth homeowner asks before they commit: do you pay less now for hardwood and top it up with oiling every summer, or spend a little more upfront on composite and forget about it? The honest answer is that the two are closer on day-one price than most people expect — composite has quietly compressed to sit right alongside premium hardwood — so the decision comes down to how you weigh maintenance, heat and how long you plan to stay in the house.

Upfront cost: closer than you'd think

In the Perth metro market, both materials sit in a similar band once you include the subframe, boards, fixings, labour and GST:

Prices are Perth metro, GST included, re-verified against 90+ sources. The overlap is the headline: entry-level composite now starts below merbau, and premium composite tops out around the same $580/m² as a good hardwood. Treated pine remains the budget option, but it buys you the shortest lifespan and the most upkeep.

Where the two genuinely differ

Maintenance. This is the decision-maker. A hardwood deck in Perth needs oiling once or twice a year to hold its colour and fend off the sun — budget roughly $200–$500 a year if a professional does it, or $50–$100 in product if you're comfortable doing it yourself. Composite asks for almost nothing beyond a hose-down and the occasional sweep. Over a decade, that maintenance gap is where composite quietly claws back its slightly higher starting price.

Heat. Perth summers are the one place composite loses ground. Darker composite boards can climb past 60°C in full afternoon sun, which matters if the deck sits off a west-facing living area with no shade. Lighter colours and modern capped, textured boards run cooler, but timber — particularly a light-oiled hardwood — still tends to feel more forgiving underfoot in January. If your deck bakes all afternoon, factor shade sails or a pergola into either choice.

Look and feel. Hardwood gives you genuine grain and that warmth timber lovers want, at the cost of the yearly oiling ritual. Today's premium composites are convincing enough that the timber-versus-composite question fades once the boards are down, but a purist will still pick jarrah or merbau every time.

The ten-year number

Say you build a 25 m² deck. A merbau build might land around $12,000 to $14,000, then cost $200–$500 a year to maintain — call it $2,000–$5,000 over ten years. A comparable composite build might start a touch higher but add almost nothing in upkeep. By roughly year seven to ten, the running totals cross, and from there composite is cheaper to own. The break-even point moves earlier the bigger your deck and the more you'd pay for professional oiling.

That's the crux: if you're building a small deck and you enjoy the maintenance, hardwood can be the cheaper long-term choice. If it's a large deck, or the idea of oiling it every summer fills you with dread, composite usually wins the lifetime maths.

Which should you choose?

Choose hardwood if you want authentic timber grain, you're building a smaller deck where upfront savings matter more, and you don't mind the annual upkeep. Choose composite if low maintenance is the priority, your deck is large, or it's shaded enough that summer heat isn't a concern. Whichever way you lean, get three quotes that specify the same board and the same subframe spec — the substructure is often the biggest hidden cost, and a cheap quote frequently means a lighter frame that shortens the life of the deck regardless of the boards on top.

Frequently asked questions

Is composite really more expensive than timber in Perth?

Not dramatically. Composite runs $295–$580/m² installed in Perth, merbau hardwood $315–$580/m² — they overlap almost entirely. Composite's slightly higher entry point is usually offset within a decade by zero oiling costs.

Does composite decking get too hot for Perth summers?

Darker boards can, reaching 60°C+ in direct afternoon sun. Lighter colours and textured, capped composites run noticeably cooler. If your deck faces west with no shade, choose a light board or add a pergola or shade sail.

How much does it cost to maintain a hardwood deck in Perth?

Around $200–$500 a year for professional oiling, or $50–$100 in product if you do it yourself, applied once or twice annually. Composite needs virtually none of this.

Which lasts longer, composite or timber?

Hardwood like merbau or spotted gum lasts 25–40+ years with regular oiling; composite lasts 25–30 years with almost no upkeep; treated pine 15–20 years. Longevity on timber depends heavily on maintenance.