Upkeep is the reason that comes up again and again in the owner accounts below. That means oiling every year, grey boards when the oiling gets skipped, and rot where a deck never dries. The people who stay with timber have their reasons too, and heat comes up most. I'd want both sides on the table before choosing, so this guide sets them out, mostly in owners' own words.
Composite decking vs timber: the reasons people actually switch
Oiling fatigue comes first. The big hardware chain's own advice is to oil or finish a hardwood deck every year, and to oil treated pine yearly too1. Reviewers of a popular decking oil on ProductReview talk about a fresh coat every six to twelve months, and one with a north-facing deck wrote that it stopped repelling water within a few months4. It isn't a quick job either. A Whirlpool member wrote in December 2025 that timber is "days of work to maintain" once you count the pressure washing, the drying and a couple of coats of oil10. On the same thread another member wrote, "I wish I had built my front deck with composite," because a fresh coat every year is a pain10. A third said they had oiled their merbau diligently for the first several years until life got too busy, and that their next deck will be composite.
Tannin bleed is the second. New merbau bleeds tannin when it gets wet, and the usual advice is to let the deck weather for eight to ten weeks, until the tannin has leached out, before oiling it3. Left alone, the stain can land on whatever is next to the deck. A Whirlpool member who had a treated pine deck replaced with merbau in early 2021 hosed the first day's run-off from their Colorbond walls before it set14. After a few days of rain and wind, though, the stain had dried on, and a hose and scrubbing brush couldn't shift it. Composite isn't entirely free of it either, and one maker says tannin water marks will show on its uncapped boards early in the deck's life7.
Rot is the third. One Whirlpool member described in August 2024 how a south-facing timber deck that never sees the sun was showing black marks after a wet year, with some rot around the nails, four years after they moved in and did nothing to it11. Another wrote in November 2020 that the merbau decking at their body corporate had been replaced twice in ten years, the second time with composite13. Composite boards are sold as rot-resistant, but one maker points out that timber joists under them will eventually rot, so I'd check the frame as hard as the boards.
Then there are splinters and grey boards. Timber left to weather goes silver-grey. One Whirlpool member's treated pine deck, never oiled, did exactly that over 37 years10. A composite maker adds that dried-out timber splits and splinters. A Whirlpool member wrote in August 2024 that they had replaced their merbau deck with Millboard two years earlier because they couldn't be bothered sanding and oiling it and watching the wood go grey11. A long-term Ekodeck owner on ProductReview wrote in May 2026 that their deck had been down since 2013 in the western sun and was still in excellent shape with some fading16. The same owner was glad to have chosen it over timber.
Random lengths are a smaller thing, but a real one. Hardwood decking can come that way, and one merbau line is supplied in a mix of lengths from 1.8 m to 5.7 m2. You cut around the short ones and join boards over joists. Composite comes in set lengths such as 5.4 m, and one maker asks for full-length boards on any deck up to that length, with breaker boards beyond it in place of butt joins8.
The honest reasons people don't switch
Heat is the complaint that comes up most in these accounts. A Melbourne member of the hardware chain's Workshop forum wrote in November 2020 that at a showroom, at midday on a sunny 22–24°C day, every composite brand was too hot to stand on, while the hardwood samples were much more bearable15. A Whirlpool member in south-east Queensland wrote in December 2025 that their composite deck is too hot for bare feet on some days, though they have nothing to do to it, unlike timber10. Another wrote in August 2024 that composite samples they had put in the sun beside several timbers the year before came out about 10°C hotter on average on a thermal camera, and that they went with large-format paving instead11. One maker says its darker boards can run up to 20°C or more above the air temperature5. I'd choose the colour and plan the shade before choosing a brand, and does composite decking get hot goes through what you can do about it.
Upfront cost is next. The hardware chain's guide puts composite above hardwood on cost, and hardwood above treated pine. The member who started the December 2025 Whirlpool thread had quotes for the same deck in merbau and in composite, and the composite quote was higher10. Another member on the thread said they wouldn't pay more for composite than for real timber. The counter-argument is the oil, the labour and the timber boards you might otherwise replace. Whether that adds up for you depends on how long you'll own the house, and is composite decking worth it works through it. For current board pricing by state, see prices.
Look and feel stops some people, and that's fair. A Whirlpool member who had just laid fifty square metres of merbau in October 2013 called the composite alternative "Too fake" and noted that it still scratches and can't really be sanded12. I wouldn't settle this from photos, so get a sample in your hand.
Scratches and marks are the last of it. An OzBargain member wrote in July 2017 that Ekodeck and similar boards "scratch relatively easily" and get very hot underfoot, and told the poster to go ahead only if both sounded manageable18. A Whirlpool member who laid a small test area of ModWood in 2012 found that dirt and water from pot plants left marks that never came out properly12. One member on the December 2025 Whirlpool thread pointed out that a damaged timber board can be sanded and oiled, while a scratched composite board has to be replaced10. If the deck has faded by then, the new board won't match. A ModWood reviewer on ProductReview made that complaint in May 2025, writing that one broken board meant replacing the boards across the whole area to get a colour match. The reviewer's follow-up says the boards were in a screen17. Composite decking fading and scratches covers what to expect.
Composite decking vs merbau: the bits that change on site
If you're swapping merbau for composite on the same frame, the joist spacing and the joins both change. One composite maker's maximum for a home deck is 450 mm centres5, while Timber Queensland's advice lets 19 mm hardwood decking span 500 mm9, so I'd measure the old frame before assuming it will do. Composite also grows along its length as it warms, about 1.1 mm per metre between 15°C and a hot day by one maker's figure6. That calls for end gaps and breaker boards in place of the staggered butt joins a timber deck uses. Expansion gaps in composite decking explains the gaps, and composite decking on an existing deck frame covers what to check before you reuse a frame.
The frame is the real catch. I wouldn't put a board with a twenty-five-year warranty6 on H3 pine joists that are already ten years old without checking them first. If the posts and bearers are tired, the money saved by keeping them is spent again when the frame gives out under good boards.
Who should stay with timber
If the deck is under a roof or out of the afternoon sun, and you don't mind a day with a lamb's wool applicator every year, timber is cheaper and some people simply prefer the feel of it. A roof changes the sums. One Whirlpool member wrote in December 2025 that after about five years of oiling, a roofed pergola over their timber deck meant not touching it for the thirty-odd years since10. Another wrote in 2012 that oiling their timber deck about twice a year took a couple of hours one Saturday and an hour on the Sunday, and was less of a pain than expected12.
What I'd do
Get a composite sample and a piece of the timber you're considering. Leave them side by side where the deck will go, then touch both at three in the afternoon on a hot day. If you can stand on the composite, I'd weigh the oiling you'll save against the extra outlay. If you can't, pick a lighter colour, plan some shade, or stay with timber and budget for the oiling. Then read what is composite decking if you want to understand what you're buying, and use the deck designer to see what the boards and a suitable frame come to for your size.