Ask three builders to quote a Merbau deck and you'll often get three very different numbers — and no obvious way to tell which one is actually right. That's not you failing to shop around properly; it's that "Merbau decking" isn't one product with one price. Below is what a Merbau deck actually costs on the Central Coast, exactly what moves that number up or down, and how to read a quote so you're comparing like with like.
Average Cost Per Square Metre for Merbau Decking
As a general planning range for the Central Coast:
| Scope | Typical cost |
|---|---|
| Board supply only | $75 – $115 |
| Supply & install, standard ground-level subframe | $180 – $280 |
That's a wide range for what sounds like one product, and the gap between $180 and $280 per square metre on a 30m² deck is over $3,000 — which is exactly the kind of spread that makes quotes hard to compare. The figures above are a starting point for budgeting, not a quote; the next section is why the range is so wide in the first place.
What Affects the Price
A full Merbau deck construction quote is built from several separate line items, and where your deck sits within each one is what actually determines the final number:
- Substructure. A ground-level deck on stable soil needs the least substructure work. An elevated deck needs deeper footings, more bearers and joists, and sometimes engineering certification — all before a single Merbau board goes down.
- Access. Tight side access, no vehicle access to the backyard, or a build that requires materials carried in by hand all add labour time that a straightforward front-yard job doesn't.
- Board grade. Standard structural-grade Merbau costs less than premium select-grade boards, which are picked for fewer knots, straighter grain and more consistent colour. If colour consistency matters to you, ask which grade is actually being quoted.
- Fixings. Face-fixed boards (visible screw heads) are cheaper and faster to install than a hidden or secret-fixing system, which costs more but leaves a cleaner finished surface with no screws to see.
Merbau vs Composite vs Treated Pine — Cost Comparison
Merbau sits in the middle of the three most common decking choices on the Central Coast:
| Decking material | Typical installed cost |
|---|---|
| Treated pine | $160 – $220 |
| Merbau | $180 – $280 |
| Ekodeck composite | $220 – $320 |
Treated pine is the cheapest to install but the shortest-lived and least resistant to Central Coast salt air. Merbau costs more upfront but delivers a hardwood look and feel that pine can't match. Composite sits above both on day-one price but needs no oiling or sanding over its life — worth weighing if you're deciding purely on cost rather than the timber look Merbau is chosen for.
Hidden Costs Cowboy Builders Won't Mention
The quotes that look cheapest on paper are often missing line items that show up later as extra invoices, or as problems you only discover once the deck is built:
- Substructure remediation. If old footings or bearers are reused without inspection, rot or inadequate sizing discovered mid-build becomes a "surprise" additional cost.
- No engineering or council sign-off. Skipping this on an elevated deck is cheaper today and a real liability later — especially if you ever sell the property.
- Cheap fixings. Non-marine-grade screws corrode fast in salt air and need replacing within a few years, undoing any saving on the original job.
- No allowance for board waste. Natural hardwood has more offcut waste than composite; a quote that doesn't allow for it is quietly under-quoting the board count.
We regularly get calls from homeowners whose deck needs work within a few years of a cut-price build — see our deck repair and restoration page for the kind of issues that turn up.
Why Cheap Quotes Often Cost More Long-Term
A low quote usually means one of the line items above has been cut, not that the builder found a genuinely cheaper way to do the same job. Undersized footings, skipped flashing, or boards laid without proper spacing for movement don't fail on day one — they fail two, three or five years in, as cupping, squeaking, rot at fixing points, or a deck that no longer feels solid underfoot. At that point you're paying for a repair or a rebuild on top of what you already spent, which is a worse outcome than paying a fair price once.
The way to avoid this isn't necessarily picking the most expensive quote — it's picking the one that's itemised clearly enough that you know exactly what you're getting for the price.
Getting an Accurate On-Site Quote
No two Merbau decks cost the same, because no two sites, substructures or access points are the same — which is exactly why a phone estimate or a generic "per square metre" figure can't be relied on for your actual project. An accurate quote needs someone to measure the site, assess ground conditions and access, and confirm board grade and fixing method with you before a number goes on paper. That's how we quote every custom deck design and build, Merbau included — a fixed, itemised price, not a range.
If you want a number specific to your site rather than a range, get in touch for a free on-site quote.