Hardwood Decking vs Composite Decking

Hardwood and composite are the two decking categories that come up most for Adelaide decks, and both are genuinely good choices — the right one depends on how much ongoing maintenance you're willing to do, budget, and how the deck actually gets used, not one being straightforwardly better than the other. We lay four hardwood species regularly — Merbau, Jarrah, Spotted Gum and Blackbutt — so "hardwood" isn't just one look or one price point either.

Cost

Hardwood costs less upfront than composite, in both material and typically installation, though the four species aren't priced the same as each other. Merbau is the most affordable and most commonly requested; Jarrah, Spotted Gum and Blackbutt all cost more for the timber itself. As a guide, 10 square metres of Merbau decking typically costs around $6,800 (incl. GST) — see our full timber decks page for what that covers, and a free on-site quote for an exact figure in one of the other species. Composite costs more to buy and install than any of the hardwoods, but the maintenance cost gap narrows the calculation over a decade or more, since hardwood needs periodic oiling that composite simply doesn't.

Choosing a Hardwood Species

All four hardwoods we lay are genuine, durable Australian and South-East Asian hardwoods, well suited to Adelaide's climate — the real differences are colour, cost and a few practical traits:

• Merbau — a rich reddish-brown that darkens further with age, the most affordable of the four and the most common decking timber used across Adelaide. The deck pictured on this page is Merbau.
• Jarrah — a deep red-brown Western Australian hardwood, dense and very durable, at a higher price point than Merbau.
• Spotted Gum — attractive natural colour variation board to board, prized for its strength and for staying grippy underfoot even when wet, which suits a deck near a pool.
• Blackbutt — a lighter, pale straw-brown colour, and one of the more fire-resistant Australian hardwood species, worth knowing if bushfire attack level (BAL) requirements apply to your site.

Maintenance

This is the real trade-off between hardwood and composite generally, regardless of which hardwood species. All four need periodic oiling to keep their colour — left unoiled, hardwood weathers to a silver-grey over a year or two, a look plenty of people actually like, but it's a genuine colour change, not decay. Composite needs nothing more than an occasional clean; no oiling, no sealing, no sanding back a greyed surface. If ongoing upkeep is the deciding factor, composite wins outright.

Heat Underfoot

Composite, especially in darker colours, tends to get noticeably hotter underfoot on a hot Adelaide summer day than hardwood of a similar shade. Lighter composite colours close the gap but don't fully eliminate it. This is worth real weight around a pool or anywhere bare feet are involved through summer, more than it usually gets credit for at the material-selection stage.

Durability

Both hardwood and composite last decades on a properly built frame — see how a deck's frame, bearers and joists actually go together on our timber decks page, since the frame determines lifespan more than the decking material sitting on top of it. Where they differ: hardwood can develop minor surface checking (small splits along the grain) in extreme heat if left unoiled for long periods, and can splinter at board edges over many years of wear. Composite won't rot, splinter or check the way timber can, but its surface layer can show scuffs and wear over a long service life, particularly in high-traffic areas.

Appearance

Hardwood is genuine timber, so every board has its own natural grain and colour variation — part of what gives a timber deck its warmth, and visible in the Merbau deck pictured above. Composite is manufactured from a mix of wood fibre and plastic for a deliberately consistent colour and grain pattern board to board, which suits a cleaner, more uniform, contemporary look. Neither is more "correct" — it's a genuine style preference once the practical trade-offs above are weighed up.

At a glance:

• Cost: hardwood cheaper upfront (Merbau least, Jarrah/Spotted Gum/Blackbutt more); composite's higher price narrows over a decade once oiling costs are counted in.
• Maintenance: all hardwoods need periodic oiling; composite needs just an occasional clean.
• Heat underfoot: composite runs noticeably hotter in direct summer sun, especially in darker colours.
• Durability: both last decades on a properly built frame; hardwood can check or splinter if left unoiled, composite can scuff in high-traffic areas.
• Appearance: hardwood has natural grain variation and warmth; composite gives a consistent, uniform, contemporary look.

Which One Should You Choose?

If you don't mind an annual or biennial oiling job and want the warmth and natural variation of real timber, hardwood is the lower-cost, well-proven choice — Merbau (pictured, used on our own Glen Osmond deck build) is the most affordable starting point, with Jarrah, Spotted Gum and Blackbutt as options if a different colour or trait suits your site better. If you want to never think about maintenance again and a consistent, uniform finish matters more to you than natural grain, composite's higher upfront cost buys you exactly that, with the trade-off of running hotter underfoot in direct summer sun.

Hardwood vs Composite Decking FAQ

See our full timber decks page for how a deck is actually built, or our real Glen Osmond deck build this page's photo comes from.