Key takeaways
- Modwood / mid-tier composite $480-$720/m2, Trex / premium $620-$920/m2 fitted (Adelaide, 2026)
- Dark composite boards reach 60-70C in direct Adelaide summer sun - choose lighter, capped boards for barefoot areas
- Capped (co-extruded) composite resists fade and stains far better than uncapped first-generation boards
- We connect you with 3 independent builders so you compare brand, capping and warranty side by side
Jump to: indicative costs, common questions, or the full cost guide.
Modwood, Trex and the capping that matters
Composite decking is a wood-plastic blend. The first generation was uncapped and faded badly. Modern boards are capped: a hard polymer shell co-extruded over the core that resists fade, scratches and stains. When you compare composite quotes, the capping is the detail that separates a board with a 25-year warranty from one that chalks out in 5 years.
Modwood is the Australian-made mid-tier name most Adelaide builders carry. Trex is the premium US brand with the longest fade-and-stain warranty. Both are good products; the right one depends on budget, colour range and how much sun the deck takes. Our Modwood vs Trex guide compares them line by line.
Composite never needs oiling or staining. It does need an occasional wash. The maintenance saving over timber is real, but it is not zero work, and the upfront price is 40 to 80 percent higher than a merbau deck of the same size.
The Adelaide heat problem no brochure mentions
This is the single most common composite regret in Adelaide. Dark composite boards in direct summer sun reach 60 to 70 degrees - hot enough that you cannot stand on them barefoot in January. Timber stays noticeably cooler because it does not hold heat the same way.
The fix is not to avoid composite. It is to choose a lighter board colour for any area used barefoot (around a pool, off a bedroom), and to factor in afternoon shade. A builder who has installed composite through a few Adelaide summers will raise this before you sign. One who has not, will not.
Decking Adelaide briefs every builder on the comparison scope so your 3 quotes cover the same board grade. A deck over $20,000 inc GST still needs a BWC-licensed builder, a written contract and building indemnity insurance - composite does not change the SA licensing rules.
Composite Decking costs in Adelaide
Indicative 2026 ranges. No SERP competitor publishes structured pricing - we do, so you can sanity-check any quote.
| Deck type | Indicative range |
|---|---|
| Modwood / mid-tier composite, fitted | $480-$720 / m2 |
| Trex / premium capped composite, fitted | $620-$920 / m2 |
| Medium composite deck (25-50 m2 Modwood/Trex) | $18,000-$38,000 |
Indicative metro Adelaide ranges for 2026. Brand, capping grade, substructure and balustrading move the final figure. Your 3 quotes will be itemised.
BWC licence verified
Every builder we connect you with holds a current SA Building Work Contractor's licence, checked on the CBS register.
Itemised quotes
Frame, boards, fixings, oil and balustrades as separate line items - so you compare like for like.
Independent builders
Real, licensed Adelaide deck builders - never a cash-only operator working without insurance.
Composite Decking - frequently asked questions
Dark composite boards reach 60 to 70 degrees in direct summer sun, which is too hot for bare feet. Lighter board colours run cooler, and afternoon shade helps a lot. If the deck is used barefoot - around a pool or off a bedroom - choose a light, capped board. Timber stays cooler if heat is your main concern.
It is maintenance-light, not maintenance-free. Composite never needs oiling, staining or sanding, which is a genuine saving over timber. It does need an occasional wash to clear pollen, dust and mould. Capped composite resists stains far better than uncapped first-generation boards.
Both are sound. Modwood is Australian-made, mid-tier and widely stocked here. Trex is premium with the longest fade-and-stain warranty and a wider colour range. The right pick depends on budget and sun exposure. Our Modwood vs Trex guide compares them in detail.
Composite costs 40 to 80 percent more upfront than a merbau deck because the board itself is far dearer to manufacture. The argument for it is the lifetime maintenance saving - no oiling, no recoating - plus consistent colour. Whether that pays back depends on how long you keep the home.
Avoid the cash-only cowboy
The biggest decking risk in South Australia is an unlicensed, cash-only builder. With no BWC licence there is no building indemnity insurance, no recourse through CBS or SACAT if the work fails, and your house insurance can decline rot or structural claims tied to unlicensed work. Here is how to tell the two apart.
Walk away if
- Cash only, no written contract, no GST invoice
- Cannot give a BWC licence number to check
- Wants a deposit well above the 5% legal cap
- Quotes a single lump sum with no itemised breakdown
A real builder has
- Current BWC licence, verifiable on the CBS register
- Written contract and building indemnity insurance over $20,000
- Deposit at or under the 5% legal cap
- Itemised quote - frame, boards, fixings, finish, balustrades
Every builder we connect you with is BWC-verified. Read our full guide to BWC licensing in South Australia.
Get 3 quotes for composite decking
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