Hardwood vs composite decking on the Byron Bay coast

A Byron Bay deck quote usually comes back with three material options: treated pine, hardwood (merbau, spotted gum), or composite. The per-sqm rates look close enough on paper that most homeowners pick on upfront cost alone. The 10-year total tells a very different story — and Byron's salt, sun and termite pressure pushes that story further than most cities.
Quick answer — hardwood vs composite decking in Byron Bay
| Material | Supplied & installed | Lifespan in Byron |
|---|---|---|
| Treated pine | $205–$400/sqm | 10–15 years (annual oiling) |
| Merbau hardwood | $345–$630/sqm | 25–40 years |
| Spotted gum / blackbutt | $420–$700/sqm | 30–50 years |
| Composite (Modwood, Trex, Ekodeck) | $320–$630/sqm | 25–30 years |
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The three options on every Byron Bay quote
Three quotes from local Byron Bay builders typically come back with the same shortlist: treated pine, a hardwood (merbau, sometimes spotted gum or blackbutt), and a composite (Modwood, Trex, Ekodeck). Each sits in a different price band and has a different relationship with Byron's climate.
The spread inside each band is wider than the gap between bands. A premium merbau install with stainless fixings, a hardwood subframe and complex level changes can land above a basic composite deck on a flat block. A budget treated-pine deck with rough finish on a small backyard can come in under a third of any composite quote.
The right call depends on three things: how long you plan to own the property, how much salt the deck will see, and how much maintenance you're willing to do.
1. Treated pine — cheapest day one, fastest to silver
Treated pine is the entry-level option. It's a softwood (typically radiata) pressure-treated with copper-based preservatives to H3 or H4 grade for outdoor use. In Byron Bay, expect $205–$400 per square metre supplied and installed for the basic spec.
A 25sqm backyard deck in Mullumbimby or Suffolk Park can land at $6,000–$10,000 in pine, against $13,000–$18,000 for the equivalent in merbau. That's meaningful, especially for a rental property or a deck you know you'll replace in a renovation cycle.
The catch is what Byron's climate does to it. Without annual oiling, treated pine silvers fast — within 18 months you're looking at a grey, dry, splintery surface. With oiling every 12–18 months ($200–$400 per session for a 25sqm deck), it holds up reasonably well for 10–15 years. After that, board cupping and rot at the fixing points usually force full board replacement.
2. Hardwood — the Byron Bay sweet spot
Merbau is the most common hardwood used for Byron decks — $345–$630 per sqm supplied and installed. It's naturally dense, oil-rich, and resistant to termites and rot. With basic upkeep (re-oil every 2–3 years) it lasts 25–40 years in Byron's climate.
Spotted gum and blackbutt sit one tier above at $420–$700/sqm. Both are Australian hardwoods rated Class 1 for durability. Spotted gum is naturally termite-resistant — the Byron shire sits in a high-termite-risk zone, and even with a treated subframe, having termite-resistant boards reduces ongoing inspection cost and stress.
Hardwood's real weakness in Byron is salt. Even merbau will check, split, and split fixings on a beachfront deck at Wategos or Belongil within 8–12 years if not specifically detailed for coastal use — stainless 316 fixings, end-grain sealing, regular salt-water washing. The coastal-salt-zone deep-dive covers this case in detail.

3. Composite — zero-maintenance, higher day-one cost
Composite decking has matured from the chalky early-2010s product to something that looks and behaves close to real timber. Current Byron rate: $320–$630/sqm supplied and installed. The mainstream brands are Modwood, Trex Transcend, Ekodeck and NewTechWood.
What you're paying for: a wood-and-recycled-plastic composite that doesn't need oiling, doesn't splinter, won't silver, and is immune to termites. In Byron's climate that's genuinely valuable — the salt-and-humidity combination that punishes timber simply doesn't affect composite. Lifespans are 25–30 years.
Real trade-offs: composite gets hotter underfoot than hardwood in direct sun (an issue for north-facing pool decks), the colour palette is limited and reads slightly flat next to real timber, and damaged boards usually need full-length replacement.
The 10-year total cost — not the per-sqm rate
Most homeowners read decking quotes on per-sqm rate, which makes pine look like the obvious winner. The way to actually read them is on 10-year total — install plus expected maintenance plus probability of replacement.
| Material (25sqm deck) | Install | 10-year maintenance | 10-year total |
|---|---|---|---|
| Treated pine (basic) | $7,500 | $2,500 | $10,000 |
| Treated pine (premium) | $10,000 | $2,500 | $12,500 |
| Merbau hardwood | $13,500 | $1,200 | $14,700 |
| Spotted gum | $16,500 | $1,200 | $17,700 |
| Composite (Modwood) | $13,500 | $0–$300 | $13,500–$13,800 |
On a 10-year horizon, premium pine and merbau and Modwood land within $4,000 of each other once maintenance is included. By year 12 the pine deck typically needs significant board replacement; merbau and composite have years left. Over 15 years the cost winners are merbau and composite. Over 30 years — the long-hold family home horizon — it's the hardwoods.
Frequently asked questions
Is composite decking worth the extra money in Byron Bay?
Yes on two specific use cases: beachfront coastal homes where salt would cripple timber, and rental or short-stay properties where the hardwood oiling cycle doesn't fit the management model. On a hinterland family home where the deck is lived on for decades, hardwood usually wins on look and resale value.
How long does a treated pine deck actually last in Byron Bay?
With regular oiling every 12–18 months: 10–15 years before board replacement is needed. Without oiling: 5–8 years before the surface becomes splintery and unpleasant. Byron's high humidity and salt-bearing breezes are harder on pine than most Australian cities.
Which hardwood is best for a coastal Byron Bay deck?
Spotted gum if budget allows — Class 1 durability, naturally termite-resistant, and handles salt better than merbau. Merbau is the workhorse choice and performs well if specified with 316 stainless fixings, end-grain sealing, and a freshwater rinse after heavy salt-spray days.
Will composite decking get too hot for bare feet in summer?
Direct full-sun composite can reach 60–70°C on a 35°C Byron afternoon — too hot for bare feet for several hours either side of midday. Hardwood typically reads 8–12°C cooler in identical conditions. If the deck is shaded by pergola or trees, it's not an issue.
Do I need a permit for a deck in Byron Shire?
Byron Shire requires a building permit for decks more than 1m above natural ground level, decks larger than 25sqm, or any deck attached to a dwelling. Ballina and Tweed Shires have similar thresholds. Most decking specialists handle the application as part of the quote.
Can I mix materials — hardwood frame, composite boards?
Yes, common spec choice. Treated hardwood or merbau subframe (which never sees direct weather) plus composite boards combines structural longevity with low-maintenance surface. Expect to pay $20–$40/sqm more than a full composite system but save on board replacement over decades.
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