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M&B Building Products recently put Accoya to the ultimate test, using it to build this deck and jetty for a canal-side home in Mandurah, WA. “Its altered structure means it absorbs significantly less water than other woods,” Hansel says. “So it’s an ideal choice for decking around pools.” Good to know: The acetylation process involves the use of acetic acid. Because residual acid contained in the timber may corrode regular steel, use stainless steel or brass nails and screws when fixing acetylated wood.
Save Email Acetylated wood is marketed under the brand name Accoya, and has been available in Australia for several years. Mark Hansel from M&B Building Products in Western Australia says that Accoya also has great eco-credentials: the wood is sourced from sustainable, fast-growing forests and the manufacturing process is non-toxic.
2. Acetylated wood If you’re not sold on the appearance of composite decking boards, but remain hesitant about the ongoing demands of timber, acetylated wood might be the product for you. Acetylation is a century-old treatment that alters the chemical structure of the wood, making it stronger and more ‘dimensionally stable’, so it does not expand and contract in response to changes in temperature and humidity. The timber becomes resistant to cracking, splintering and decay, and in Europe and the US it’s widely used for exterior applications such as windows, doors, cladding, and – you guessed it – decking. If you’re curious about how the acetylation works, this document explains it in more detail.
Look out for: The type of plastic used in the composite mix or outer capping can impact on the hardness, and therefore durability, of composite boards. If they’re going to be subject to heavy traffic from pets and kids, choose a product made with PVC, which will provide maximum UV resistance, stain-resistance and hardness.
If the deck faces north or west and is likely to become hot in the sun, choose a lighter-coloured composite decking product, such as this DuraLife decking in ‘Garapa Grey’, which mimics the look of weathered timber. Paler colours won’t absorb as much heat from the sun. Bonus: if scratches occur, they’ll be less obvious.
So now for the million-dollar question – what brand of composite boards will best suit your needs? There’s no answer really, as each product has slightly different attributes that will suit different purposes. “There are lots of composites out there, and some are good and some are not that good,” Wilkinson says. “But if you pay for a middle-of-the-range composite product, you’re going to get a good job.” If you live in a bushfire-prone region, consider flame-resistant decking by INEX, Biowood or Modwood, which was used for the stepped decking in this Perth garden. In high-rainfall or damp areas, Aulburn recommends Ekodeck. “I used this for an internal courtyard with no direct sun and water issues and it is performing well,” he says.
Another way in which composites differ from timber is the way they’re installed. “Most composite decking systems utilise concealed fixings,” Aulburn says. “They’ll have either a clip that goes in between the two boards that holds them down, or a track that they clip into. You don’t see any screws or nails, and it creates a nice sleek look.” Aulburn chose Huskwood in ‘Charcoal’ for this hidden-away deck in a garden on Sydney’s Northern Beaches. The dramatic colouring and streamlined, nail-free fixings create a striking finish.
“Often people fall into the hope that their [timber] deck is going to look like floorboards inside,” says Rod Aulburn, owner of Sydney company Get Decked Out. “It’s not – decking boards are milled differently, generally from a different part of the tree, they’re finished differently, and they’re exposed to the weather.” For clients who want a ‘set and forget’ deck that’s going to perform more like floorboards inside and age more predictably, Aulburn recommends composites. “Composites are initially dearer per metre than a hardwood decking, but then if you lay a hardwood deck you’ve got to consider the cost of sanding and finishing, and depending on how much sun it gets, regular re-oiling,” he says. “Whereas with the composites, there’s no additional expense for ongoing maintenance. So you catch up pretty quickly.”
In terms of longevity, Wilkinson says some of the new generation of composites are warrantied for 25 years, and so far he hasn’t had any clients come back to him with problems. He adds: “But who knows? The products haven’t been out that long here in Australia. But they are getting better all the time.” While early-generation composites were susceptible to scratching and fading, manufacturing methodologies have changed and the new-generation composites use harder plastics, a lower wood-plastic ratio, and are ‘capped’ with an integrated protective plastic coating, all of which helps to overcome these issues. The deck pictured here was built using capped Fiberon boards in ‘Ipe’ with the dining zone picked out in ‘Tudor’.
Composite boards are designed to look and feel similar to timber decking, but are virtually maintenance free: they won’t warp or rot, and never require resealing or painting. “A hardwood timber deck such as merbau or jarrah looks absolutely beautiful once you put it down and you give it two coats of oil,” says Paul Wilkinson, owner of Castlegate Home Improvements in WA. “But the truth is that’s the best it’s ever going to look. After a few years of not getting proper maintenance, it starts to look tatty. Whereas the composite board is maintenance free, and that’s what sells it.”
1. Composite decking An environmentally friendly decking option, composite decking is made from recycled wood pulp, fibre or sawdust, mixed with plastic and machine-extruded into long, uniform boards, (often more than five metres in length). The actual composition varies between brands – some products use rice husks or bamboo rather than wood, and some use recycled plastics.
The market for alternative decking materials has exploded over the past few years, and there are a multitude of different products available, at a wide range of price points. Most timber decking alternatives are known as ‘composite’ decking, and are a wood-plastic hybrid. These include brand names such as Modwood, Trex (pictured here), CleverDeck and Ekodeck. Other alternatives are fibre-cement decking boards, and timber that’s been chemically modified to resist weathering and decay. While it’s great to have this kind of choice, it can be difficult to know which product will be best suited to your needs. So let’s look at how the different types of alternative decking boards perform.
Cairns-based builders Kenick Constructions installed compressed fibre-cement product HardieDeck in its newest display home, pictured here. “We chose HardieDeck because up here in the tropics, it’s a very harsh environment and we find that customers often don’t want a high-maintenance timber deck,” says marketing manager Rachel Whymark. Unlike the plastic-wood composites, fibre-cement decking does need to be sealed with either a good-quality water-based paving paint or a penetrating sealer. “Design-wise it’s really flexible, because you can paint it any colour you like or it can be stained to look like timber,” Whymark says. Finished with a clear sealer, it will look like polished concrete.
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