Timber Decking

It depends on where the deck is being built. Spotted gum is the strongest all-rounder: Class 1 durability, BAL-29 rated, handles coastal and bushfire zones. Ironbark is the best choice for tropical environments and any application involving in-ground contact. Blackbutt suits temperate zones where visual consistency matters. Jarrah is the specification for southern states and marine-adjacent projects. There’s no universally “best” species, only the right species for the climate, BAL level and use case.

A properly specified, installed and maintained hardwood deck can last 40 to 50 years in Australian conditions. Class 1 species like spotted gum, blackbutt and ironbark are expected to resist biological decay for 40+ years above ground. Maintenance matters. Recoating every 12 to 24 months in coastal and tropical zones, every 24 months in temperate zones, keeps the finish intact and extends life.

Two things. First, we’re a manufacturer, not a wholesaler. We control the grading, kiln drying, profiling and pre-finishing, and we manufacture every order for the project. Second, our profiles are engineered around natural timber movement. Boards will expand and contract, and a cheaper profile that doesn’t allow for that will disengage in a hot summer. Our systems are designed to stay tight and aligned through seasonal cycles.

Yes. Standard board sizes for each system are listed on the individual product pages (Metroplank, Classicplank, Marineplank), but we manufacture to order and can accommodate non-standard sizes for specific projects. Get in touch with the team to discuss what’s possible.

All Mortlock decking comes with a standard 6-year warranty, with extended project-specific warranties available for commercial and large-format work. Our team provides detailed maintenance guidance for each product, and we’re available during and after installation to support the builder through any technical questions.

Yes, up to BAL-29. Spotted gum, blackbutt and ironbark all meet the BAL-29 density threshold under AS 3959:2018. Jarrah and Pacific teak are suitable for BAL-12.5 and BAL-19. Burnt Ash is not BAL rated. Mortlock does not supply decking rated for BAL-40 or BAL-FZ. Those classifications generally require non-combustible materials.

Six hardwood decking species to choose from: Spotted Gum, Ironbark, Blackbutt, Jarrah, Pacific Teak and Burnt Ash. Species availability varies slightly between Metroplank, Classicplank and Marineplank systems. Check the individual product pages or get in touch for the current spec sheet.

Supply-only. Mortlock manufactures and supplies the product. Installation is handled by your chosen carpenter, landscaper or decking contractor. We provide installation guides and on-site support where needed, so the installer has everything they need to get the system right the first time.

Yes. That’s part of what “manufacturer, not wholesaler” means. Boards are pre-oiled with Cutek Colourtone for colour retention, or with Clear Cutek CD50 for maximum penetration and moisture control. Raw (unfinished) decking is also available if your spec calls for on-site coating.

Composite decking has its place, but it lacks the warmth, grain, and long-term character of real hardwood. Our decking systems are engineered to handle the same conditions composite is marketed for (pool surrounds, commercial foot traffic, coastal exposure) while offering natural material, carbon storage credentials, and a 40 to 50 year service life. We break the comparison down in detail in our timber vs composite guide.

Typical lead time is around 8 weeks. Every order is manufactured for the specific project. Species, profile, board size and finish, rather than pulled off a rack. That’s deliberate. It’s how we make sure what arrives on site matches the spec exactly.

Timber is hygroscopic, so the same species will behave differently depending on where the deck is built. As a general guide, Class 1 species (spotted gum, ironbark, blackbutt) are preferred for coastal and tropical zones. Ironbark has a distinct advantage in tropical environments as the only species we supply rated Class 1 both above ground and in-ground. In temperate zones, both Class 1 and Class 2 species perform well, so jarrah and Pacific teak are also on the table. For arid inland sites, specify pigmented coatings and allow two to four weeks of on-site acclimatisation. Thermally modified burnt ash can offer better dimensional stability in rapidly changing conditions.

Early. If the site is in a bushfire-prone area, the BAL assessment determines which species you can specify. Under AS 3959:2018, BAL-29 requires timber density above 750 kg/m³ at 12% moisture content. Spotted gum, blackbutt, and ironbark all meet that threshold. Jarrah and Pacific teak sit at BAL-12.5 to BAL-19. Burnt ash is not BAL rated. No Mortlock decking product is rated for BAL-40 or BAL-FZ.

All Mortlock decking arrives pre-oiled with Cutek Colourtone or Clear Cutek CD50. To hold the natural colour, recoat every two to three years. There is no such thing as a no-maintenance real timber deck, and we’d rather be upfront about that on a discovery call than have a client surprised three years in.