Hardwood vs composite decking cost on the Sunshine Coast
On the Sunshine Coast a typical 30m² hardwood deck (merbau or spotted gum) sits between $7,500 and $13,500 installed. Composite — Modwood, Trex, EkoDeck — runs $9,500 to $16,000 for the same footprint. The headline says composite costs more upfront. The total-cost-of-ownership picture is more complicated, especially in subtropical humidity and within 2km of the coast.
Quick answer — hardwood vs composite decking cost on the Sunshine Coast
| Material | Per-sqm installed | 30m² total | Lifespan | Maintenance |
|---|---|---|---|---|
| Merbau (Class 1 hardwood) | $250–$390 | $7,500–$11,700 | 25–35 yrs | $150–$300/yr (oil 2-yrly) |
| Spotted gum (Class 1) | $290–$450 | $8,700–$13,500 | 30–40 yrs | $150–$300/yr |
| Blackbutt (Class 2) | $310–$460 | $9,300–$13,800 | 30–40 yrs | $150–$300/yr |
| Modwood (composite) | $340–$510 | $10,200–$15,300 | 20–25 yr warranty | ~$0 (clean only) |
| Trex Transcend (composite) | $410–$580 | $12,300–$17,400 | 25 yr warranty | ~$0 |
| EkoDeck (composite) | $290–$450 | $8,700–$13,500 | 20–25 yr warranty | ~$0 |
Three things that decide hardwood vs composite on the Sunshine Coast
1. Subtropical humidity changes the timber maintenance math
Sunshine Coast summers run 75–85% humidity for months at a time. Hardwood decks need oiling every 18–24 months to prevent silvering, warping, and surface cracking — about $150–$300 per 30m² in product plus a weekend of labour if DIY, or $450–$900 if hiring out. Composite decking eliminates that entirely — no oiling, no sanding, no annual maintenance. Over 25 years, hardwood incurs roughly $3,000–$6,000 in maintenance that composite doesn’t. That closes the upfront cost gap almost entirely.
2. Surface temperature in Queensland summer sun
A common composite complaint on the Sunshine Coast is heat retention. Dark composite boards can hit 65°C+ in direct summer sun — uncomfortable on bare feet, brutal for pets. Hardwood runs 5–12°C cooler under the same conditions because timber doesn’t absorb heat the same way. If your deck gets all-day western sun and you’ll walk it barefoot, lighter-coloured composite (sand, beige, light grey) or hardwood is the better call than dark composite.
3. Pool-zone slip rating and BCA code
Sunshine Coast pool decks within 1.5m of the water need slip-rated boards under BCA Part 3.10.1. Hardwood meets the rating with grooved or ribbed profiles ($30–$50/sqm premium over plain). Composite is generally pool-rated at install, but verify the brand certificate — some budget composites aren’t classified. The Modwood Pro and Trex Transcend ranges are explicitly pool-rated; budget EkoDeck variants often aren’t.
Itemised example — Mooloolaba 30m² deck, hardwood vs composite side-by-side
| Item | Spotted Gum | Modwood Xtreme |
|---|---|---|
| Material — 30m² boards + offcuts | $4,500 | $7,200 |
| Bearers, joists, posts (treated pine substructure) | $1,800 | $1,800 |
| Stainless steel screws (316 marine grade) | $380 | $380 |
| Joist tape / waterproof membrane | $220 | $220 |
| Site prep + measure | $480 | $480 |
| Installation labour (2 days, 2-person team) | $2,200 | $2,400 |
| Initial timber oil treatment / clean-down | $260 | $80 |
| TOTAL | $9,840 | $12,560 |
Frequently asked questions
Is merbau really 25 years on the Sunshine Coast?
Yes, with maintenance — oiled every 18–24 months, stored under cover during install, and laid with proper drainage. Without oiling, merbau silvers and starts surface-cracking by year 8–10. With consistent oil cycles, 25–30+ years is realistic on the Sunshine Coast.
Which composite brand is best for Sunshine Coast humidity?
Trex Transcend and Modwood Xtreme rate best for subtropical exposure — both use capped polymer outers that resist humidity-driven board cupping. Budget composites (cheaper EkoDeck variants, hardware-store generics) tend to cup and fade within 5–8 years on the Sunshine Coast.
Can I lay hardwood over an existing deck substructure?
If the substructure is sound (treated pine bearers and joists, no rot, correct span), yes — it saves $1,500–$3,000 on a typical reno. Get a builder or carpenter to inspect the substructure first; many Sunshine Coast decks have hidden joist damage from past humidity cycles.
How often does composite actually need cleaning?
Annual hose-down for most installs; twice-yearly for pool decks or decks under jacaranda/poinciana drop. Stain removal (mould, oil, food) uses standard deck cleaner — same as hardwood. The "no maintenance" claim refers to no oiling/sealing, not no cleaning.
Does composite increase home value differently than hardwood?
On the Sunshine Coast, hardwood (especially spotted gum and blackbutt) marginally outperforms composite at resale because buyers associate it with premium character. The gap is small — typically 1–3% of deck cost. Both are well-received compared to no deck at all.
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