Iron Bark Decking

Grey ironbark decking: sizes, lengths and prices

Sold in random lengths, 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 Grey ironbark decking is like

Grey ironbark, mainly Eucalyptus paniculata with E. drepanophylla and E. siderophloia, is the heaviest timber in our decking range at about 1,106 kg/m³ seasoned, and the hardest: WoodSolutions gives a seasoned hardness of 16 kN, roughly double Merbau. The colour is light grey to light chocolate with darker red and brown boards mixed through, and the grain is interlocked and dull rather than figured.

Durability is Class 1 both above ground and in the ground, which is why the same timber is sold as posts and bridge timber. The heartwood is termite resistant and the sapwood is not susceptible to lyctid borer, so there is little that needs to be cut out of a pack.

Where it suits

This is the board for decks that get punished: commercial walkways, pool surrounds, shaded decks that stay damp, anywhere a dropped tool or a dragged chair would mark a softer timber. The limit is bushfire: grey ironbark qualifies under the AS 3959 density rule for BAL-12.5 and BAL-19 but is not on the bushfire-resisting timber list, so it cannot be used for decking at BAL-29. For BAL-29 choose Spotted Gum, Blackbutt or Merbau.

Fixing and finishing

Pre-drill everything and expect to replace drill bits; at 16 kN the timber blunts tools quickly. Two stainless or Class 3 galvanised screws per board per joist, 450 mm joist centres, 4–5 mm gaps on the wide board. Being so dense it takes oil slowly, so apply thin coats of CUTEK Extreme CD50 or Intergrain Universal Timber Oil and wipe off the excess. Screws are in decking accessories.

The same timber for other jobs

• Grey Ironbark solid floorboards – 130 × 14 mm Feature grade in stock, other sizes ordered in
• Ironbark cladding
• 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 ironbark decking cost?

On our website on 14 October 2026, 86 × 19 mm is $10.62 per lineal metre and 135 × 19 mm $15.90 per lineal metre, the same price per metre as Grey Box and below Blackbutt in the wide board.

Is ironbark the hardest decking timber?

Of the species we stock, yes: 16 kN seasoned hardness against 15 for Grey Box, 10.1 for Spotted Gum and 8.5 for Merbau.

Can I use it at BAL-29?

No. It is not on the AS 3959 bushfire-resisting timber list, so it stops at BAL-19 for decking, which it meets on density.

Is it red or grey?

Both come through in a pack: light grey and light chocolate boards with some darker red-brown ones. Oiled, the mix evens out.

Why is it harder to lay?

Weight and density. A 5.4 m 135 × 19 board is about 15 kg, every screw needs a pilot hole, and saw blades dull faster.

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.