The boards are the part of a deck you see and walk on every day, so it is no surprise they are the first thing people ask about. In South East Queensland the choice usually comes down to two: a hardwood such as spotted gum, blackbutt or merbau, or a composite board made from wood fibre and plastic. Both make a good deck. They behave differently in our sun and rain, and they ask different things of you afterwards.
Hardwood: the look people know
A hardwood deck has real grain, varies board to board and feels like timber underfoot. Spotted gum and blackbutt are Australian hardwoods with good natural durability above the ground. Merbau is a dense imported hardwood with a deep red-brown colour, and it is common on Brisbane decks.
Hardwood moves with the weather. Boards swell a little in the wet season and shrink in the dry, and the surface weathers to silver-grey if it is left bare. Tannins can bleed out of new merbau in the first rains and stain concrete or render nearby, so we plan for that around the edges.
The upkeep with hardwood
- Oil or stain it after the build, once the timber has had time to weather in a little.
- Re-coat on a regular cycle. A deck in full sun needs it more often than one under a roof.
- Wash off leaves and dirt so they do not hold moisture against the boards.
- Check for raised nails or screws and lifting board ends once a year.
Skip the oiling and the deck still stands up, but it greys, the boards check (small surface splits) sooner and the finish looks tired. Under a patio roof, a hardwood deck keeps its colour far longer, which is why so many of the decks we build go in under a new roof.
Composite: less work, different feel
Composite boards are made from a mix of wood fibre and plastic, usually with a hard outer shell on the better boards. They do not need oiling, they do not split or splinter, and the colour stays fairly even for years. A wash with soapy water is most of the maintenance.
They are not timber, and up close they do not look like it. Some people love the clean, even finish; others want real grain. We bring samples to the quote so you can see and feel them in your own light.
Heat underfoot
This matters in Queensland. Any deck in full afternoon sun gets hot, and dark composite boards can get hotter than a pale hardwood. If the deck is around a pool where people walk barefoot, choose a lighter colour, put a roof over part of it, or both. Under an insulated patio roof, the boards stay shaded and the question mostly goes away.
The frame changes with the board
Every decking product has its own rules for the frame under it, set by the board maker. Composite boards usually need joists closer together than hardwood, plus the gaps the maker specifies at the ends and sides so the boards can expand in the heat. Hardwood board spans come from Timber Queensland’s tables for the species and grade.
So the board choice comes first, then we size the frame to suit. Changing your mind from hardwood to composite after the frame is built can mean adding joists.
Termites and moisture
Termites are active across South East Queensland. Composite boards are far less attractive to them than timber, but the frame under the boards is what carries the deck, and a timber frame close to the ground still needs the right treatment and an inspection zone. A steel frame takes termites out of the frame question altogether. Our steel or timber frame guide goes through this in detail.
Bushfire areas
On a lot mapped as bushfire prone, the deck has to meet the bushfire standard for the site. Some hardwood species are accepted at certain bushfire attack levels, and some composite products are tested and rated, but not all are. We check the rating for your lot and pick a board that is accepted for it before we quote.
Which one we suggest
- Choose hardwood if you want real timber, are happy to oil it, and the deck is shaded or under a roof.
- Choose composite if you want low upkeep, the deck is in the open, or it is a rental where nobody will oil it.
- Choose a light colour of either for a deck in full sun or around a pool.
- If you might roof it later, design the frame and footings for the roof now.
What we need at the quote
Tell us how you will use the deck, how much sun it gets and whether you want a roof over it now or later. We measure the height at the lowest point of the ground, check the slope and the council mapping, and price the frame, boards, balustrade and stairs together, with the approval included.
