The Long-Term Cost Showdown: Composite vs Timber Decking
It’s a common question about whether you should build a deck in timber or composite. Sometimes it comes down to how the different decking materials compare. Most people focus on the upfront price per square metre. But the real question is what your deck will cost you over its full life. It’s not just how much it costs you to install it! To think that, or to advise you to only consider the cost of building would not be laying it out fairly for you to make a good decision.
A timber deck might seem cheaper to build, but once you add years of sanding, oiling, and maintenance, (and the inordinate number of hours to do all of that work) the total investment can look very different. Let’s break down what you can expect to spend over 10 to 20 years on the Sunshine Coast.
Understanding Total Cost of Ownership
Upfront vs ongoing costs
The upfront cost is your build price. It’s what you outlay for materials, labour, and any council approvals. The ongoing cost covers everything you’ll spend to maintain, clean, and occasionally repair the deck.
Why this matters for coastal homeowners
The Sunshine Coast’s humidity, salt air, and UV exposure are tough on outdoor timber. Factoring in long-term upkeep helps you make a smarter choice for your location and lifestyle.
And it’s even tougher on the timber on the areas that are constantly in the sun. They warp, crack and generally fair worse than protected areas. So, please take that into consideration.
How to Compare Composite and Timber Decking Costs
Here’s a simplified comparison of real-world costs based on current 2025 prices and maintenance patterns typical for Sunshine Coast homes.
| Timeframe | Composite Deck (e.g. Trex, NewTechWood) | Timber Deck (e.g. Spotted Gum or Merbau) |
| Initial Cost (Installed) | $700–$1,200 per m² | $450–$900 per m² |
| Maintenance (per year) | $0–$100 | $200–$500 |
| Expected Lifespan | 25–35 years | 15–25 years |
| 10-Year Ownership Cost | ~$8,000 per 20m² deck | ~$10,000–$12,000 per 20m² deck |
| 20-Year Ownership Cost | ~$11,000–$14,000 per 20m² deck | ~$18,000–$22,000 per 20m² deck |
(All prices include GST and assume professional installation.)
Why Composite Decks Win on Lifetime Value
Minimal maintenance
Composite decking doesn’t need sanding, oiling, or staining. A quick wash a few times a year keeps it looking fresh, even through summer storms.
Long-term durability
Unlike timber, composite boards don’t rot, cup, or splinter. They’re built from recycled fibres and polymers that withstand years of Queensland heat and salt exposure.
Colour longevity
UV-resistant coatings mean the colour stays consistent without annual re-treatment. This is a big plus for decks exposed to full sun.
Why Some Homeowners Still Choose Timber
Natural beauty
For many people, nothing quite matches the warmth and grain of real timber. It’s a classic look that feels organic and timeless.
Lower upfront cost
It’s a fact that timber remains more affordable to install, especially for small or low-level decks where labour and engineering are minimal.
Repair flexibility
If a board gets damaged, it’s easy to sand and replace. Timber decks can also be re-stained or refinished to suit changing styles.
Maintenance Breakdown Over Time
Timber decking
A typical 20m² timber deck requires sanding and re-oiling every 12–24 months. The less protected the timber, the more often it needs attention. Each treatment can cost between $400–$800, depending on condition and labour. Over 20 years, that’s thousands in upkeep. Each time you maintain your deck it takes hours of your time (the price of which is often not figured into the cost). Often your deck cannot be used while the materials cure.
Composite decking
Manmade decking materials require only occasional cleaning with mild detergent and water. Even after 10 years, most surfaces remain structurally sound and visually intact, with zero refinishing costs.
Repairs and replacements
Because timber decks absorb moisture, individual boards may need replacement after 10–15 years or even sooner. Composite boards, on the other hand, are resistant to decay and insects, reducing that risk dramatically. Many composite decking boards have warranties of 20 to 25 years.
Environmental Impact and Sustainability
Composite decking
Made from recycled plastic and reclaimed wood fibres, polymers or resins, composite boards can divert waste from landfill and reduce the need for deforestation.
Timber decking
Sustainably sourced Australian hardwoods (like Spotted Gum and Blackbutt) remain eco-friendly options when certified under FSC or PEFC schemes. However, imported timbers or treated pine can have larger environmental footprints.
Choose Decking Materials that are Right for You
Choose composite if…
- You want a low-maintenance deck that lasts decades
- You live near the beach or in a humid area
- You prefer consistent colour and minimal upkeep
Choose timber if…
- You love the look and feel of natural wood
- You’re on a tighter upfront budget
- You don’t mind regular maintenance as part of your home care routine
Key Takeaways
- Composite decks cost more upfront but less over time.
- Timber decks require ongoing maintenance and refinishing.
- Over 10–20 years, composite decking typically offers better value and durability.
- Local Sunshine Coast conditions favour composite for longevity. However, both options can perform well with proper care.
- Bottom line: Do your research and make your decision!
If you need help making the right decision for you, and want to talk through all the considerations, and discover what really matters to you, then talk with us at Sunshine Coast Decking.