Hardwood timber decks look unbeatable on day one. Composite decks look unbeatable on year fifteen. The real question is which one gives you better value over the life of your deck — and the answer depends on deck size, climate, and how much of a weekend you want to spend re-oiling boards.
Timber Decking Cost
| Timber Type | Per m² (installed) | 40m² Deck |
|---|---|---|
| Treated pine | $220–$320/m² | $8,800–$12,800 |
| Merbau (sustainable) | $280–$400/m² | $11,200–$16,000 |
| Blackbutt | $320–$450/m² | $12,800–$18,000 |
| Spotted gum | $340–$480/m² | $13,600–$19,200 |
| Ironbark / Jarrah | $380–$550/m² | $15,200–$22,000 |
Composite Decking Cost
| Composite Grade | Per m² (installed) | 40m² Deck |
|---|---|---|
| Entry-level uncapped | $320–$420/m² | $12,800–$16,800 |
| Capped composite (Ekodeck, Futurewood) | $380–$500/m² | $15,200–$20,000 |
| Mid-range (Trex, NewTechWood) | $450–$580/m² | $18,000–$23,200 |
| Premium (Trex Transcend) | $520–$650/m² | $20,800–$26,000 |
| Fully concealed fixing system | + $40–$80/m² | + $1,600–$3,200 |
20-Year Total Cost Comparison (40m² deck)
| Cost Component | Hardwood Timber | Capped Composite |
|---|---|---|
| Supply & install | $13,000–$18,000 | $16,000–$22,000 |
| Oiling (every 1–2 yrs) | $4,000–$8,000 | $0 |
| Sand & recoat (2–3 times) | $3,000–$7,000 | $0 |
| Board replacement (~10%) | $800–$1,500 | $0 |
| Annual cleaning | $200–$400 | $100–$200 |
| 20-Year Total | $21,000–$34,900 | $16,100–$22,200 |
Pros and Cons: Side by Side
Hardwood Timber
- Lower upfront cost — especially treated pine and sustainable Merbau
- Warmer natural look and feel — preferred in heritage and coastal homes
- Boards can be individually replaced if damaged
- Sands back beautifully — can look brand new after a recoat
- Works with all decking frames and substructures
- Requires oiling every 1–2 years or greying sets in within 6 months
- Splinters, movement, and cupping are common after 5 years
- Susceptible to termites if ground-contact sections are untreated
- Can warp, split or discolour under harsh Australian sun
- Higher total 20-year cost once maintenance is factored in
Capped Composite
- Zero oiling, sanding, or sealing required for life of deck
- Warranty of 25–30 years from reputable brands (Trex, Ekodeck)
- No splinters, no movement, stable colour
- Resists termites, rot, moisture, and mould
- Lower total cost over 20 years in most Australian climates
- Higher upfront price (typically 25–40% more than equivalent hardwood)
- Surface can reach 15–20°C hotter than timber in direct summer sun
- Mid and entry-grade composites can look plastic close up
- Colour cannot be changed later — you pick it once, you keep it
- Damaged boards can be tricky to replace mid-deck (colour match)
Which Should You Choose?
Choose hardwood timber if:
- You're building a smaller deck (under 25m²) where maintenance is manageable
- You love the authentic grain and warmth of timber and don't mind ongoing upkeep
- Your budget is tight and you need to minimise upfront cost
- You're in a temperate climate where sun damage is moderate
Choose capped composite if:
- You're building a larger deck (40m²+) where maintenance hours add up fast
- You're in a coastal, tropical, or high-UV area (Gold Coast, Darwin, Perth)
- You want the lowest 20-year total cost and zero weekend recoats
- The deck is for kids, rental, or commercial use — durability matters more than character
Most Australian homeowners who've owned both say they would choose composite for the next build — not because timber is worse, but because time is the real hidden cost.
Frequently Asked Questions
Is composite decking cheaper than timber in Australia?
Composite costs 25–40% more upfront — around $380–$600/m² installed versus $250–$450/m² for hardwood timber. Over 20 years, composite usually works out cheaper because timber requires oiling every 1–2 years and sanding/recoating every 5–8 years.
How long does composite decking last?
Quality capped composite (Trex, Ekodeck, NewTechWood, Futurewood) lasts 25–30+ years with most brands offering a 25-year residential warranty. Entry-level uncapped composite lasts 15–20 years.
Does composite decking get hot in the Australian sun?
Yes — composite surfaces can be 15–20°C hotter than timber in direct sun. Light colours (stone, sandstone, oak) run cooler than dark colours (charcoal, espresso). For north-facing decks in Sydney/Brisbane, this matters.
Can I lay composite decking over my old timber deck?
Only if the sub-frame is still sound. Most composite brands require joists at 300–400mm spacing (vs 450mm for timber) so the frame usually needs re-spacing or replacement. Budget $40–$80/m² for a new frame if required.
Is composite decking worth it for coastal homes?
Yes — composite is one of the most coastal-proof decking options available. Unlike timber, it does not rot, warp, or need salt-wash maintenance. Many coastal councils in NSW and QLD now recommend composite for exposed decks.
How much does a 40m² composite deck cost in 2026?
A 40m² capped composite deck in Australia costs $15,200–$26,000 fully installed, depending on grade and fixing system. Compare that to $11,200–$22,000 for equivalent hardwood, before any maintenance.
Get 3 decking quotes from local builders — prices vary significantly by area and brand.
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