Composite vs Timber Decking: The Complete Australian Comparison

Which decking material is right for your outdoor space? Here’s everything you need to know.

Choosing between composite and timber decking is one of the biggest decisions you’ll make when building or renovating your outdoor space. Both materials have devoted fans, and both have genuine advantages depending on your priorities.

This guide cuts through the marketing spin to give you an honest, side-by-side comparison of composite vs timber decking. We’ll cover costs (upfront and long-term), maintenance requirements, durability, appearance, and which material makes sense for different Australian conditions.

What is Composite Decking? Complete Guide →

Quick Comparison: Composite vs Timber at a Glance

Before we dive into the details, here’s a snapshot of how composite and timber decking compare across the factors that matter most:

Factor	Composite	Timber
Upfront Cost	$100-$190/m²	$60-$180/m²
Annual Maintenance	Occasional cleaning	Oiling, staining, sealing
Maintenance Cost	Minimal (cleaning only)	$30-$80/m²/year
Lifespan	25-30+ years	15-25 years (with care)
Termite Risk	None	High (requires treatment)
Splinters	Never	Common
Colour Retention	Excellent	Greys naturally
20-Year Total Cost	Lower	Higher

Cost Comparison: The Real Numbers

Let’s address the elephant in the room: composite decking costs more upfront than most timber options. But that’s only half the story.

Upfront Material Costs

For decking boards alone (not including subframe or installation):

Composite decking: $100-$170 per square metre depending on quality tier (capped vs premium ASA-capped)

Timber decking: $60-$180 per square metre depending on species (treated pine at the low end, spotted gum and merbau at the high end)

On a typical 30m² deck, that’s a difference of roughly $1,200-$2,100 in material costs. However, installation costs are often lower for composite due to faster installation times and hidden fastening systems.

Composite Decking Cost Guide 2026 →

The Hidden Cost: Ongoing Maintenance

Here’s where the economics shift dramatically. Timber decking requires annual maintenance to stay in good condition:

Annual oiling/staining: $30-$80 per square metre (DIY) or $50-$120 per square metre (professional)

Time investment: 4-8 hours annually for a typical deck (sanding, cleaning, applying finish)

Potential repairs: Replacing warped, cracked, or rotted boards adds additional costs

For a 30m² timber deck, you’re looking at $900-$2,400 per year in maintenance costs if you hire a professional, or $900-$2,400 plus a full weekend of your time if you DIY.

Composite decking? Occasional cleaning with soap and water. That’s it.

20-Year Total Cost of Ownership

When you calculate total cost of ownership over 20 years, the numbers tell a clear story:

30m² Composite Deck	30m² Timber Deck
Materials: $4,500-$7,500	Materials: $2,400-$5,400
Installation: $2,400-$5,400	Installation: $3,000-$6,000
20-year maintenance: ~$0	20-year maintenance: $6,000-$16,000
TOTAL: $6,900-$12,900	TOTAL: $11,400-$27,400

Bottom line: Composite decking typically pays for itself within 5-7 years and continues saving you money for decades after.

Maintenance: Weekend Warrior vs Set-and-Forget

This is where the two materials couldn’t be more different.

Timber Decking Maintenance

Timber is a natural material that needs regular care to perform its best:

Annual oiling or staining is essential to prevent moisture penetration, UV damage, and greying. Skip a year and you’ll notice the difference.

Regular sanding may be needed to remove splinters and prepare the surface for finishing.

Mould and mildew treatment is often required, especially in humid climates or shaded areas.

Board replacement becomes necessary when boards warp, crack, cup, or rot — which they inevitably will over time.

Some people genuinely enjoy this ritual — the smell of fresh oil, the satisfaction of seeing their deck restored. If that’s you, timber might be the right choice.

Composite Decking Maintenance

Composite decking is engineered for minimal upkeep:

Sweep regularly to remove leaves and debris

Wash occasionally with soap and water (2-4 times per year)

That’s it. No oiling. No staining. No sealing. No sanding. No painting.

Composite Decking Maintenance Guide →

Durability: How They Handle Australian Conditions

Australia throws everything at outdoor surfaces — intense UV, driving rain, humidity, temperature extremes, and of course, termites. Here’s how each material copes:

UV Resistance

Composite: Premium capped composite decking includes UV stabilisers and protective ASA layers that resist fading. Most quality brands warrant against significant colour change for 25-30 years.

Timber: All timber will grey and silver without regular UV-protective finishes. Even with annual oiling, some colour change is inevitable.

Moisture Resistance

Composite: Capped composite boards have a protective polymer shell that prevents moisture absorption. They won’t rot, swell, or warp from water exposure.

Timber: Wood is hygroscopic — it absorbs and releases moisture constantly. This causes swelling, shrinking, warping, and eventual rot if not properly maintained.

Termite Resistance

Composite: Completely termite-proof. The plastic content makes composite boards inedible to termites.

Timber: Even treated timber remains vulnerable to termites over time. In Australia — where termite damage costs homeowners billions annually — this is a serious consideration.

Structural Integrity

Composite: Quality composite decking comes with 25-30 year structural warranties. It won’t crack, splinter, or rot.

Timber: Lifespan varies significantly by species and maintenance. Well-maintained hardwood can last 25+ years, but poorly maintained softwood may need replacement in under 10.

Appearance: Natural vs Engineered Beauty

This is often where personal preference plays the biggest role.

The Case for Timber

There’s no denying the natural beauty of real timber. Species like spotted gum, blackbutt, and merbau have unique grain patterns, natural colour variations, and a warmth that many homeowners love. Each board is genuinely unique.

However, that beauty requires work to maintain. Left untreated, timber will grey and weather. Oiled timber needs regular re-coating to maintain its colour.

The Case for Composite

Modern composite decking has come a long way from the obviously plastic-looking boards of 20 years ago. Premium composite now features realistic wood-grain textures, natural colour variations, and finishes that closely mimic popular timber species.

The key advantage? That appearance stays consistent year after year without any effort. What you see on day one is essentially what you’ll see on year ten.

Composite also offers colours and finishes (like contemporary grey tones) that aren’t naturally available in timber.

Safety Considerations

Splinters

Timber decking splinters. It’s unavoidable, and it’s one of the biggest concerns for families with young children or pets. Regular sanding helps but doesn’t eliminate the risk.

Composite decking never splinters. The engineered surface remains smooth throughout its lifespan.

Slip Resistance

Quality composite decking is manufactured with textured surfaces that provide excellent grip, typically rated R11/P5 for slip resistance. When properly maintained, it’s actually less slippery than many timber options when wet.

Both materials can become slippery if covered in algae or moss, which is why regular cleaning matters regardless of material.

Fire Rating

For homes in bushfire-prone areas, fire rating matters. Many premium composite decking products are rated to BAL-29, making them suitable for most bushfire zones. Some timber species also meet BAL requirements, but options are more limited.

Heat Retention: The Barefoot Test

One area where timber has a genuine advantage is heat retention. All decking materials absorb heat in direct sunlight, but composite tends to get hotter than timber due to its plastic content.

If you’re building a deck that will receive full afternoon sun and you want to walk on it barefoot, this is worth considering. Solutions include:

Choosing lighter coloured composite boards (they stay noticeably cooler than darker colours)

Planning shade coverage for high-traffic areas

Positioning the deck to avoid peak afternoon sun

Environmental Considerations

Composite: Most composite decking is made from recycled materials — reclaimed wood fibres and recycled plastics that would otherwise end up in landfill. At the end of its life, some composite products can be recycled again.

Timber: Sustainably sourced timber from certified forests is a renewable resource. However, the environmental cost of regular maintenance (chemical finishes, transport, application) adds up over time. Imported hardwoods may also have questionable supply chain practices.

Neither option is definitively ‘greener’ — it depends on specific products, sourcing, and how you weight different environmental factors.

Which is Right for You?

Choose Composite Decking If:

You want minimal ongoing maintenance

You’re building for long-term value (10+ years)

You have young children or pets (no splinters)

You’re in a termite-prone area

You want consistent appearance year after year

You’re building a pool deck or coastal property

Choose Timber Decking If:

You want the authentic look and feel of natural wood

You enjoy deck maintenance as a ritual

Upfront budget is your primary constraint

You prefer natural materials over engineered products

You’re building in a heavily shaded area with minimal sun exposure