Blackbutt Decking

Blackbutt decking in 86 × 19 mm and 135 × 19 mm: a pale, golden Australian hardwood with Class 1 durability above ground, Janka hardness 8.9 kN and a place on the AS 3959 bushfire-resisting timber list, so it can be used for decking up to BAL-29.

• Sizes: 86 × 19 mm and 135 × 19 mm
• Timber: Australian Blackbutt (Eucalyptus pilularis), grown from Bega in NSW to Maryborough in Queensland; golden yellow to pale brown; about 900–930 kg/m³
• Durability: Class 1 above ground, which the Queensland Government rates at more than 40 years’ expected life; Class 2 in-ground; the heartwood is termite resistant
• Bushfire: on the AS 3959 list of bushfire-resisting timbers, so it can be used for decking up to BAL-29 (BAL-40 and Flame Zone need tested systems)
• Genuine Blackbutt: some suppliers sell other species under the name “Blackbutt”, which can differ in colour, durability and bushfire rating. Ours is Australian Blackbutt
• Joist spacing: 450 mm centres, as WoodSolutions recommends for decking; its deck design guide allows up to 500 mm for 19 mm hardwood, or 350 mm if the boards run at 45°
• Gaps: 3–4 mm between 86 mm boards and 4–5 mm between 135 mm boards at installation (WoodSolutions deck design guide)
• How much for a deck: a 20 m² deck needs about 140 lineal metres of 135 mm board or about 225 lineal metres of 86 mm, plus about 10% for offcuts
• Low decks: under 400 mm off the ground, WoodSolutions suggests 5–6 mm gaps and at least 40 mm between the deck and the house, for airflow
• Fixing: two fixings per board at every joist, at least 12 mm from edges and ends. Pre-drill this dense hardwood. Use stainless steel within 1 km of the coast or 1 m of a pool. See our decking screws
• Finishing: coat every face and cut end, ideally before fixing, then recoat at least once a year or as the oil maker directs (WoodSolutions); left bare, it weathers to silver-grey. Oils we stock: CUTEK CD50, Intergrain Universal Timber Oil or Sceney’s Timber Decking Oil
• At Greenhill: stocked at 170 Settlement Road, Thomastown, with pickup or delivery across Melbourne and regional Victoria. Compare species on our hardwood decking page.

Blackbutt decking: sizes, lengths and prices

Both widths are sold in random lengths, usually 1.8–5.4 m, cut to suit. Prices are our website prices on 14 October 2026, per lineal metre; a 20 m² deck needs about 140 lineal metres of 135 mm board or 225 of 86 mm, plus 10% for cuts.

What Blackbutt decking is like

Blackbutt, Eucalyptus pilularis, grows along the coast from Bega in NSW to Maryborough in Queensland and is the paler of the Australian decking hardwoods: golden yellow to pale brown, with a straight grain and, now and then, a slight pink cast. It is about 900 kg/m³ seasoned, with a WoodSolutions seasoned hardness of 8.9 kN, heartwood that is naturally termite resistant, and sapwood that lyctid borer does not attack.

Its durability is Class 1 above ground, which the Queensland Government tables put at more than 40 years, and Class 2 in the ground. Be aware that some yards sell other species under the name "Blackbutt"; ours is Australian E. pilularis, which is what the bushfire listing applies to.

Where it suits

Blackbutt is on the AS 3959 list of bushfire-resisting timbers, so 19 mm boards can be used for decking up to BAL-29. The pale colour is the reason most people choose it: it stays cooler underfoot than the dark timbers and suits modern houses with pale render or light cladding. It bleeds more tannin than Spotted Gum in its first months, so hose it down before oiling and keep it off unsealed pale paving until it settles.

Fixing and finishing

Pre-drill, two screws per board per joist, 450 mm joist centres, 3–4 mm gaps on 86 mm boards and 4–5 mm on 135 mm. Coat every face and end before laying. Blackbutt takes a clear oil well and keeps its light colour better under a UV-filtered product such as CUTEK Extreme CD50; Intergrain Universal Timber Oil is the budget option. Screws and joist tape are in decking accessories.

The same timber for other jobs

• Blackbutt flooring – solid, engineered, hybrid and laminate floors
• Blackbutt solid floorboards – 83 × 14, 130 × 14 and 130 × 19 mm, Select and Standard
• Blackbutt engineered flooring – for slabs and underfloor heating
• Blackbutt cladding – the same timber on the wall
• Hardwood decking – all six species side by side

Compare the species

Our decking timber comparison puts hardness, durability, bushfire rating and price per metre for all six hardwoods on one page; Merbau decking is the budget alternative.

Questions we get asked

How much does Blackbutt decking cost?

On our website on 14 October 2026, 86 × 19 mm is $10.36 per lineal metre and 135 × 19 mm $19.90 per lineal metre.

Is Blackbutt decking BAL-29 rated?

Yes. Australian Blackbutt is on the AS 3959 bushfire-resisting timber list, so 19 mm decking can be used up to BAL-29.

Blackbutt or Spotted Gum?

Blackbutt is paler and cooler underfoot; Spotted Gum is harder (10.1 kN against 8.9), bleeds less and is cheaper per metre in the wide board here. Both are Class 1 above ground.

Does Blackbutt bleed?

Some tannin in the first wet weeks. Wash the deck down before the first oil and keep run-off away from pale, unsealed surfaces until it stops.

Will it stay that pale colour?

Under a UV-filtered oil, mostly; under a plain oil it goes a deeper honey; left bare it silvers.

Pickup and delivery

Stocked at 170 Settlement Road, Thomastown, Mon–Fri 7 am–4:30 pm and Sat 9 am–1 pm. We pack and load it for you, or deliver across Melbourne and regional Victoria; delivery is quoted with the order. Call (03) 9465 9875 with your sizes and we will work out the lineal metres and the price.

Pick up from 170 Settlement Road, Thomastown. Stocked lines are usually ready the same day. Delivery across Melbourne and regional Victoria is quoted on the order; call (03) 9465 9875 for a price on your suburb.

All prices include GST. Flooring is priced per square metre, decking and dressed timber per lineal metre, framing and posts per length. Trade accounts get trade pricing on the site and at the counter: apply here.

Bring your room or deck sizes in, or call (03) 9465 9875, and we will work out boards, lengths, fixings and oil, with about 10% allowed for cuts.