Timber Decking

Hardwood decking in Melbourne

Greenhill Timbers stocks hardwood decking at our yard at 170 Settlement Road, Thomastown, with pickup or delivery across Melbourne and regional Victoria. Merbau has been our specialty since we started out importing timber, and we also stock Australian Spotted Gum, Blackbutt, Ironbark, Grey Box and Silvertop Ash.

Which hardwood for your deck?

Merbau decking: 90, 140 and 190 × 19 mm, kiln-dried, Standard and Better grade, in set or random lengths. Orange-brown that darkens with age, Janka hardness 8.5 kN, Class 1 durability above ground, and rated to BAL-29. It can bleed tannin onto paving, so seal every face.

Spotted Gum: 86 and 135 × 19 mm, including 5.7–6.0 m long lengths. Light brown to dark red-brown, Janka 10.1 kN, Class 1 above ground, BAL-29, and less prone to tannin bleed than most species.

Blackbutt: 86 and 135 × 19 mm. Golden yellow to pale brown, Janka 8.9 kN, Class 1 above ground, BAL-29.

Ironbark: 86 and 135 × 19 mm. Grey ironbark, the densest timber in our range at Janka 16 kN, with Class 1 durability above ground and in-ground. Rated to BAL-19.

Grey Box: 86 and 135 × 19 mm. Janka 15 kN and Class 1 durability above ground and in-ground; rated to BAL-19.

Silvertop Ash: 86 and 135 × 19 mm. Pale brown, Janka 9.7 kN, Class 2 above ground, and rated to BAL-19 at 19 mm. Its heartwood isn’t termite resistant, so protect the subframe.

Building in a bushfire zone?

For BAL-29 in 19 mm boards, choose Merbau, Spotted Gum or Blackbutt. Grey Box, grey ironbark and 19 mm Silvertop Ash are rated to BAL-19. BAL-40 and Flame Zone decks need tested systems. Class 1 above ground means an expected life of more than 40 years out of ground contact.

Planning your deck

Space joists at 450 mm centres, or 350 mm if the boards run at 45 degrees. Leave 3–4 mm gaps between 86–90 mm boards and 4–5 mm between 135–140 mm boards, following the WoodSolutions deck design guide. A 20 m² deck needs about 140 lineal metres of 135–140 mm board, or about 215–225 lineal metres of 86–90 mm, plus about 10% for offcuts. Fix each board twice at every joist, pre-drill, and use stainless steel within 1 km of the coast or 1 m of a pool. Oil every face and cut end before laying, then recoat at least once a year. We stock the decking screws and decking oils to finish the job.

Ordering

Bring your deck size and we will work out boards, lengths, fixings and oil. Prefer a board that never needs oiling? Compare our composite decking. Call 03 9465 9875, Mon–Fri 7am–4:30pm, Sat 9am–1pm.

Questions we get asked about hardwood decking

Which hardwood decking is best for Melbourne?

Merbau is the value pick: stable, Class 1 durable above ground and accepted to BAL-29. Spotted Gum and Blackbutt are the Australian hardwoods with the same bushfire rating. Grey ironbark and Grey Box are the hardest-wearing boards, and Silvertop Ash is the pale, lighter option.

How many lineal metres of decking per square metre?

About 11 lineal metres per square metre for 86 to 90 mm boards with a 4 mm gap, and about 7 for 135 to 140 mm boards. Add 5 to 10% for cutting.

What joist spacing does 19 mm hardwood decking need?

450 mm centres for boards laid square to the joists, or 350 mm when the boards run at 45 degrees.

Do I need a permit to build a deck in Victoria?

Most decks do. Small, low decks can be exempt, but anything attached to the house or more than 800 mm off the ground generally needs a building permit. Our deck permit guide walks through the rules.