Compare our hardwood decking species
This table puts every hardwood decking species we sell side by side, using supplier-documented values only. Where a value is not published in our supplier documentation, the entry reads Not currently published rather than a guess. All decking is currently supplied by quote: work out quantities with the timber calculator and request a quote.
| Species | Origin | Durability classification | Colour | Grain | Density | Hardness | Common applications | Available STS profiles | Buying method |
|---|---|---|---|---|---|---|---|---|---|
| Ironbark (Grey and Red) | Australian hardwood | Class 1 above ground (supplier documented); displayed as QLD Class 1 Hardwood | Soft brown shades to rich chocolate tones and deep reds with some grey undertones | Not currently published | Grey Ironbark 1106 to 1170 kg/m3 | Janka 16 (Grey), 11.9 (Red) | Decking, screening, battens, heavy outdoor structures and high-traffic decks | 86 x 19, 135 x 19, 135 x 35 (140 x 35 option) mm | Quote |
| Spotted Gum | Australian hardwood | Class 1 above ground (supplier documented); displayed as QLD Class 1 Hardwood | Pale gold to warm brown with darker gum-vein flecking | Not currently published | 990 to 1180 kg/m3 | Not currently published | Decking, screening, cladding, flooring and exterior architectural work | 86 x 19, 135 x 19, 135 x 35 (140 x 35 option) mm | Quote |
| Blackbutt | Australian hardwood | Class 1 above ground (supplier documented) | Creamy blonde to rich honey tones with a hint of pink | Straight grain and even texture | 990 to 1100 kg/m3 | Janka 8.9 (Hard) | Decking, screening and general outdoor work | 86 x 19, 135 x 19 mm | Quote |
| Redgum (Forest Red Gum) | Australian hardwood | Class 1 above ground (supplier documented) | Soft cherry tones to deep rich burgundy | Not currently published | 1000 to 1170 kg/m3 | Janka 11.3 (Very Hard) | Decking, screening, step treads and architectural finishes inside and out | 86 x 19, 135 x 19, 135 x 35 (140 x 35 option) mm | Quote |
| Gympie Messmate | Australian (Queensland) hardwood | Not currently published | Yellowish-brown; pale straw to golden brown on the deck | Medium texture, interlocking grain | 955 kg/m3 | Janka 12 (Hard) | Decking, screening, step treads and dual decking and flooring use | 86 x 19, 135 x 19 mm | Quote |
| Jambu | Origin to be confirmed at quote | Class 2 above ground (supplier documented) | Dark grey-brown to medium brown, sometimes with a pinkish hue | Straight to slightly interlocked; medium to coarse texture | 685 to 990 kg/m3 | Janka 1,253 kgf at 12% moisture content | Decking, fencing, screening and gates | 90 x 19 mm | Quote |
| Jambu Mixed (standard grade) | Origin to be confirmed at quote | Class 2 above ground (supplier documented) | Dark grey-brown to medium brown, sometimes with a pinkish hue, with natural board-to-board variation | Straight to slightly interlocked; medium to coarse texture | 685 to 990 kg/m3 | Janka 1,253 kgf at 12% moisture content | Decking, fencing, screening and gates | 90 x 19 mm | Quote |
| Merbau | Imported | Class 2 (supplier listed) | Warm orange-brown when freshly milled, maturing to a deeper reddish brown | Not currently published | Not currently published | Not currently published | Residential decking runs, steps and general outdoor decking work | 90 x 19, 140 x 19 mm | Quote |
Durability classifications are supplier-documented natural durability ratings for decay resistance, stated for above-ground use. Service life ranges under AS 5604 are indicative classifications, not product warranties; actual performance depends on species, installation, exposure, drainage, maintenance and site conditions. Durability, strength and hardness are separate properties; see the durability classes guide.
Species profiles
Ironbark
One of the densest and most durable decking hardwoods sold in the Australian market, supplied as Grey and Red Ironbark. Supplier documentation publishes Class 1 above-ground durability with a 40+ year indicative service expectation, Janka 16 for Grey Ironbark and termite-resistant heartwood. Because it is dense and hard on tooling, Ironbark is more often supplied to order than held as broad shelf stock, so lead times can run longer. Browse Ironbark decking.
Spotted Gum
A premium Australian hardwood with pale gold to warm brown colouring and the darker gum-vein flecking the species is named for. Supplier documentation publishes Class 1 above-ground durability and an SD2 seasoned strength group. It is one of the most widely available Australian-grown decking hardwoods, which typically means shorter lead times. Browse Spotted Gum decking.
Blackbutt
Straight grained and even textured with creamy blonde to honey tones, Blackbutt is a favourite of architects and designers. Supplier documentation publishes Class 1 above-ground durability and a BAL 29 bushfire rating under AS 3959-2009. Its consistent texture takes oils and finishes well. Browse Blackbutt decking.
Redgum
Our Redgum is Forest Red Gum (Eucalyptus tereticornis), sold in the market as QLD Reds; we state the species exactly so you know precisely what you are buying. Warm cherry to burgundy tones deepen with age, and supplier documentation publishes Class 1 above-ground durability with Janka 11.3 hardness. Browse Redgum decking.
Gympie Messmate
A Queensland native sold in the market as part of the QLD Blondes group, with pale straw to golden brown tones, Janka 12 hardness and 955 kg/m3 density per supplier documentation. A durability classification is not currently published on our product pages. It has a smaller footprint in Sydney retail than Spotted Gum or Merbau, so it is typically sourced closer to order. Browse Gympie Messmate decking.
Jambu and Jambu Mixed
Jambu is a strong, stable hardwood with supplier-documented Class 2 above-ground durability and durable, termite-resistant heartwood, supplied as 90 x 19 mm decking by quote. Jambu Mixed is the standard grade line with the same documented properties and wider natural colour variation from board to board. Origin is confirmed at quote. Neither is part of our Australian hardwood range. See the full decking collection or request a quote.
Merbau
The most widely stocked decking hardwood in the Sydney retail market and the standard entry point to hardwood decking. Merbau is imported, supplier-listed as Class 2, stable and easy to work, weathering to a deep reddish brown. Note that Merbau can release tannins in its first months in service; manage runoff near light-coloured paving or render. Browse Merbau decking.
Next step
Shortlisted a species or two? Measure up, run the numbers through the timber calculator, then request a quote and we will price your options against current supplier availability. You can also compare the two Class 1 headliners directly in our Ironbark vs Spotted Gum guide.
Reviewed by the Sydney Timber Supply team. Last updated 19 July 2026.