Composite Decking vs Timber Decking: Which Is Best?

Two builders can look at the same project brief and choose different materials — and both can be right. Composite decking has earned its place in Australian construction. Timber, including natural wood decking options, hasn’t gone anywhere.

This guide covers what matters most when you’re choosing at volume: cost over time, maintenance burden, performance in Australian conditions, and what each material genuinely does better—no fluff, no sales pitch — just the comparison.

If you’re a procurement manager or volume builder, start with the cost and durability sections. If you’re specifying for a specific site, the decision table near the end will provide a quick answer.

Composite vs Timber: Side-by-Side at a Glance

Factor	Composite Decking	Timber Decking
Upfront cost per m² (boards only)	$100–180	$30–50 (treated pine) / $80–130 (hardwood)
Annual upkeep cost	Minimal — soap, water, brush	$15–25/m² (oiling, sanding, stain)
Lifespan	25+ years	10–15 yrs (pine) / 20–30 yrs (hardwood)
Termite resistance	Yes — HDPE content is indigestible	No — treatment degrades over time
Slip resistance	R11 (AS/NZS 4586)	Varies by species and surface treatment
Colour stability	ΔE ≤ 4–5 after 3,000-hr QUV test	Greys without regular oiling
Water absorption	0.2% (ASTM D1037)	5–15% depending on species of wooden decking
Warranty	15 years	Varies — often no structural warranty
Fire test data	ASTM E84: FSI 85 / SDI 300	Varies by species; untreated timber is combustible

What Does Each Decking Type Cost in Australia?

Composite decking costs more to buy. That part’s true. But the full cost picture shifts once you add timber’s annual maintenance bill into the equation — and it shifts faster than most people expect.

Upfront Board Costs: Composite vs Timber per m²

Treated pine is the cheapest entry point — boards run roughly $30–50 per m², supply-only. Hardwood species like merbau, spotted gum, and blackbutt push that to $80–130 per m² or more.

Retail composite decking boards run $100–180 per m², depending on board profile, finish, and supplier. At the lower end, that’s comparable to mid-range hardwood. At the upper end, it’s well above it. Treated pine is cheaper still — roughly $30–50 per m².

So yes, a composite costs more to buy. The gap closes once you factor in installation and disappears over time once maintenance costs stack up.

One thing many comparison articles blur: board cost is not installed cost. Composite’s hidden fastener system is faster to fit than screw-fixed timber decking. That typically saves $5–15 per m² in labour. On a 50m² build, that’s $250–750 back in the project budget.

The 10-Year Cost of Ownership

Here’s a simple model for a 50m² deck. Costs are indicative — actual figures vary by location, trade rates, and timber species.

Cost Item	Composite	Treated Pine	Hardwood (e.g. Merbau)
Boards (supply)	$5,000–9,000	$1,500–2,500	$4,000–6,500
Install (labour)	$1,750–2,500	$2,000–3,000	$2,500–3,500
Annual upkeep × 10 years	$500–1,000	$7,500–12,500	$5,000–10,000
Board replacements (est.)	Nil	$500–1,500	Nil–$500
10-year total	$7,250–12,500	$11,500–19,500	$11,500–20,500

The timber maintenance figure deserves explaining. Keeping a timber deck in good shape takes real work — oiling, sanding, and re-staining at least once a year in most parts of Australia. Regular maintenance for timber decks includes these tasks, and at DIY rates, that runs $15–25 per m² per year. At trade rates, it’s more. On a 50m² deck, that’s $750–1,250 every year, year after year.

That’s where composite pays back. Most buyers see the crossover at around 5–7 years — from that point forward, composite is the cheaper material to own.

For procurement managers specifying across multiple projects, this compounds quickly. Each site with timber adds ongoing maintenance overhead. Each site with a composite doesn’t.

Maintenance: What Each Material Needs Year to Year

Composite decking needs a wash with soapy water and a light brush a few times a year. That’s it. No oiling, no sanding, no re-staining.

Timber needs more. Quality hardwood like spotted gum or merbau needs oiling one to two times per year in high-UV areas. Treated pine needs even more attention — it greys and cracks if left dry. Factor in sanding before each oil coat, and you’re looking at a half-day of work per 50m² each cycle.

Composite isn’t zero-maintenance. Leaves, dirt, and mildew can build up in grooves, especially in shaded or wet spots. But a 20-minute clean twice a year is a different commitment to a full oiling day.

When you hand over a composite project, you hand over a low-maintenance asset. That’s a talking point with real numbers behind it — not a vague promise. For developers and body corporates, lower ongoing upkeep is a documented lifecycle advantage. For contractors, it means fewer callback jobs and a stronger case for repeat referrals.

If you’re quoting against a timber spec, this is where you win the argument on paper.

How Each Material Holds Up in Australian Conditions

Australia is hard on outdoor surfaces. UV index, coastal salt air, temperature swings, and termites all factor in. Fire risk adds another layer to many sites. Here’s how each material handles the real conditions.

UV and Colour Stability

Untreated timber greys within months in the strong Australian sun. Regular oiling slows this — but it doesn’t stop it. Over time, even well-maintained timber decks show the effects: surface breakdown, raised grain, and colour shift.

Quality-capped composite handles UV differently. The 0.8mm co-extruded cap layer shields the board core from UV attack. In 3,000-hour QUV accelerated aging tests, colour shift is held to ΔE ≤ 4–5 — a slight change, not a visible fade.

The stabiliser system matters here. HALS (Hindered Amine Light Stabilisers) combined with UV absorbers is the industry benchmark for outdoor composite. Our distributors in high-UV regions tell us this is one of the first things contractors ask about — because faded decking leads to client complaints. For boards sitting in direct Queensland or WA sun for 15+ years, this isn’t a minor detail.

Termite Resistance

Termites cost Australian property owners billions each year. Every timber deck carries some level of risk — even treated pine, as the treatment breaks down over time.

Composite decking contains no organic material that termites can digest. The HDPE plastic content makes the boards inert to termite activity. That removes a liability timber can’t fully eliminate.

For builds in termite-prone regions — Queensland, northern NSW, most of coastal WA — this is a real specification decision, not just a talking point. Composite ends the problem.

Fire Safety and BAL Ratings

Under the NCC, homes built in bushfire-prone areas must meet Bushfire Attack Level (BAL) requirements — from BAL-12.5 through to BAL-FZ. The BAL rating of a site affects which materials you can specify for decking and other exposed surfaces.

Composite decking from LastElegance has been tested to ASTM E84 — Flame Spread Index (FSI) 85, Smoke Developed Index (SDI) 300. This gives you a documented starting point for compliance conversations with your building certifier.

Timber varies widely by species. Hardwoods generally outperform pine in fire tests, but untreated timber is combustible.

Does Composite Look as Good as Real Timber?

The warmth and character of real hardwood like merbau, spotted gum, or blackbutt is hard to replicate fully. There’s a depth and variation in natural timber grain that composite boards approach but don’t perfectly match.

That said, modern co-extruded boards have come a long way. Today’s boards carry realistic wood-grain textures, natural colour variation, and consistent tone across the full range. They don’t grey off or develop raised grain over time — so a composite deck looks close to its install-day condition even five years in.

The trade-off is honest: real wood has natural beauty that takes work to keep. Composite offers a natural-style look that stays consistent without that effort.

For commercial builds, residential developments, and projects where visual consistency across a full facade matters, composite wins on lifecycle aesthetics. LastElegance decking boards share the same colour palette and surface textures as the cladding range — useful when you’re managing the full exterior look of a project.

Which Is Easier and Faster to Install?

For contractors, installation speed is labour cost. That’s the whole equation.

Composite decking uses a hidden fastener system — stainless steel clips slot into the board grooves and clip onto the joists. No surface screws. No pre-drilling required. The next board slides in and locks. The finish is clean, the install is fast.

Recommended joist spacing is 300–350mm, which is standard framing territory. Most crews adapt quickly, even if they’re new to composite.

Timber installation — especially hardwood — takes more time. Species like merbau are dense and need careful pre-drilling to avoid cracking. Screw placement and spacing matter. It’s skilled work, and it takes longer.

On a clean composite install, most contractors estimate 10–15% faster than equivalent timber work — more on larger projects where setup efficiency compounds.

Installation guides and videos are available from LastElegance, which helps crews fitting composite for the first time get up to speed without a learning cost on the first project.

Contact our sales team to discuss project scope and lead times →

Which Decking Material Is Right for Your Project?

Here’s a fast decision guide for the most common project types.

Choose composite if:

• High-traffic or commercial use — terrace, public area, body corporate building
• Pool or wet areas — waterproof, splinter-free, R11 slip-rated under AS/NZS 4586
• Termite-prone region — composite removes the risk entirely
• Long-term maintenance costs need to stay low
• Consistent appearance across a full project facade matters
• You’re buying at volume and need a reliable supply with consistent specs

Choose timber if:

• The client has a low upfront budget, and the maintenance responsibility sits with the property owner under the contract
• The design brief calls for authentic timber grain — and the client understands the upkeep commitment that comes with it
• The project spec requires FSC-certified timber, and the certifier won’t accept recycled HDPE as an equivalent

For procurement managers and distributors evaluating materials for volume supply, composite’s consistency is a real commercial advantage. Spec it once, and every board from every order looks the same. No natural variation surprises, no species availability gaps mid-project.

Frequently Asked Questions