Decking done right: a homeowner's guide
Board choices, footings, council rules and what separates a deck that lasts twenty years from one that sags in five — before you hire a deck builder.
A good deck is the cheapest extra room you'll ever add — an outdoor space that gets used more than most indoor ones. But decks live outside in Australian weather, carry real loads and often stand well off the ground, so the difference between built-properly and built-quickly shows up fast.
Before you get quotes, it helps to understand what you're actually buying: a structure, not just boards.
What building a deck involves
Every deck is two projects in one. The part you see — the boards — sits on the part you don't: footings, posts, bearers and joists. The subframe determines whether the deck stays flat and solid for decades, and it's where good builders spend their care. Elevated decks add engineering: proper footings, bracing and a compliant balustrade once the fall height crosses the threshold.
Most decks are built by carpenters or specialist deck builders. Landscapers sometimes build low platform decks as part of a bigger yard project, which is fine at ground level; once a deck is elevated or attached to the house, you want someone who builds structures for a living. Depending on the height, size and your state's rules, the job may need council approval — a good builder tells you this before you ask.
What decks tend to cost
Decking is priced per square metre installed, and the board material sets the band. A simple treated pine deck at ground level sits at the affordable end — small ones can come in around the low thousands. Popular hardwoods like merbau occupy the middle ground, with a mid-sized hardwood deck typically landing in the high single-digit thousands, and elevated composite decks with balustrade and stairs running well into five figures. All indicative — the live estimate on this page reflects your size and choices better than any average.
Composite boards cost more up front but skip the oiling and sanding cycle for their whole life, which changes the ten-year maths. Site conditions matter too: sloping, rocky or tight-access ground adds labour before a single board is laid.
Choosing your deck builder
Licensing for decks depends on your state and the job's value — larger structural work commonly requires a licensed builder or carpenter, so check your state's threshold rather than assuming. Whatever the paperwork situation, ask every quoter the same three questions: what footings are you using, what's the joist spacing, and what fixings go into the boards. You don't need to know the right answers; you're listening for whether they do, instantly and specifically.
Ask to see a deck they built five or more years ago, not last month. Any deck looks good on handover day. The subframe quality shows at year five.
Mistakes to avoid
Deck problems are almost always structural decisions made early, not board choices. Get the skeleton right and the rest is cosmetic.
- Skipping council checks — height and size rules vary, and unapproved structures bite at sale time
- Comparing quotes without checking whether footings, balustrade and stairs are included in each
- Choosing boards on price alone and ignoring the maintenance cycle you're signing up for
- Letting the subframe be built from undersized or untreated timber to hit a price
- Building hard against the house without proper flashing and drainage where it attaches
- Oiling a new hardwood deck too late — merbau especially leaches tannins and wants early attention
Indicative range only, not a quote — see the full guide for worked scenarios and what moves the price.
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