Uncommon Decking Species

Approx read time: 5 minutes

Everyone knows the favourites like spotted gum, merbau and blackbutt decking as they are popular and stocked by most timber merchants, yet other species are lesser known. We recently featured one of them, Silvertop Ash decking, in our October Easy Times. Check out the article here if you missed it.

At NHS, we stock the most common species mentioned above, but we also can supply some other lesser known species like:

  • Grey Box;
  • Turpentine;
  • Red Mahogany;
  • Grey Ironbark; and
  • Red Ironbark.

You will notice references to the colour description, grain characteristics and natural defects that can be expected and typical of that species. Interlocked grain means the angle of the wood fibres periodically changes or reverses.

Some species, like a lot of the hardwood eucalypt hardwoods, will have gum veins/gum pockets and these are a distinctive feature of those species.

Surface checking is another feature that can be common with some species and is a separation that extends along the grain of the timber surface, resulting from the surface losing moisture and shrinkage and is a natural feature of some species.

Durability class is from 1 (highest) to 4 (lowest).

The value for each species is based on trials of the resistance to both decay and termites of untreated heartwood in the ground.

The classes are:

  • Class 1- Timber of the highest natural durability, expected to have a life greater than 25 years in the ground and greater than 40 years exposed above ground.
  • Class 2 – Timber of high natural durability, expected to have a life of about 15 to 25 years in the ground and 15 to 40 years exposed above ground.
  • Class 3 – Timber of moderate natural durability, expected to have a life of about 5 to 15 years in the ground and 7 to 15 years exposed above ground.
  • Class 4 – Timber of low durability, expected to have a life of 0 to 5 years in the ground and 0 to 7 years exposed above ground. The sapwood of all species is regarded to be Class 4.

*** Please note that the photos may not truly reflect the timber colour, as some species do vary in colour tones and there are regional variances. Some species will be subject to availability and may be sourced from a range of mills.


86×19 Grey Box standard & better grade decking

Also known as (AKA): Gum-topped box or Eucalyptus Microcarpa, Eucalyptus Woollsiana, Eucalyptus Hemiphloia , Eucalyptus moluccana (botanical)

Grey box has heartwood that is a pale, yellowish brown with the sapwood paler in appearance. It has a fine, even texture and usually features an interlocked grain. Gum veins are rarely present. Grey box is very similar in appearance to coast grey box.

Grown in both the NSW and QLD regions, this decking is suited to the often-harsh Australian environment.

Grey Box as a species is slower to dry, so generally will not develop much surface checking.

Quite a dense species, it has a durability Class 1, resistant to termites and suitable for BAL (Bushfire Attack Level) 12.5 and 19 ratings. Also available in 90x22mm and 135x19mm sizes.

Available by special order from NHS


86×19 Turpentine std & better grade decking

AKA: Luster or Syncarpia Glomulifera (botanical name)

Turpentine is a large hardwood species that grows along the north-east coast of Australia between Sydney and Cairns.

Turpentine ranges from a beautiful deep chocolate, reddish brown to deep red colouring, and the texture of this timber is fine to medium. Its general appearance can be like that of the more reddish colourings of brush box.

The Turpentine grain is often wavy, with an interlocked grain. Generally it has no gum veins although it can surface check.

Turpentine is a durability Class 1, resistant to termites and suitable for BAL 12.5, 19 and 29 ratings. Other sizes available are 135x19mm and 136x22mm.

Available by special order from NHS


86×19 Red Mahogany std & better grade decking

AKA: Red Stringybark, Red Messmate, Daintree Stringybark or Eucalyptus resinifera, Eucalyptus pellita (Botanical name)

Red Mahogany is a hardwood species with generally a fine grain and a stunning attractive red colouring, displaying a range of deep red and pale pink hues. Different species of red mahogany grow in different regions, so the grain may vary. Generally, the heartwood is a deep, rich red in colour, but it may be lighter in younger material.

Red Mahogany has become a premium timber owing to a few factors like its durability, termite resistance, distinctive colouring and suitable for joinery. For a dense species it has good workability, another factor winning it favour.

Features like tight gum veins, gum deposits and pinhole borer discoloration do occasionally augment the appearance of Red Mahogany and pencil streak is common. It is a species that has good resistance to surface checking.

Red Mahogany has a durability Class 1, resistant to termites and suitable for BAL 12.5 and 19 ratings. Other sizes available are 135x19mm and 136x22mm .

Available by special order from NHS


86×19 Grey Ironbark std & better decking

AKA: White Ironbark or Eucalyptus drepanophylla, Eucalyptus siderophloia, Eucalyptus paniculata (botanical)

Grey Ironbark species is a wide variety of colour as the Grey Ironbark sapwood is almost white, making it highly distinct from the heartwood. It is grown in the coastal regions of NSW and in southern Queensland.

The colour can range from light greys or light chocolate with occasional darker reds and browns, and regionally there can be more variation.

The texture is moderately coarse and the grain usually straight, occasionally interlocked.

Grey Ironbark is an extremely hard-wearing timber that makes it perfect for high traffic areas. It is susceptible to surface checking.

It has durability Class 1, is resistant to termites, and suitable for BAL 12.5 and 19 ratings. Other sizes available are 64x19mm, 135x19mm and 140x22mm.

Available by special order from NHS


86×19 Red Ironbark std & better decking

AKA: Mugga or Eucalyptus sideroxylon (botanical)

Red Ironbark is a distinctive Australian hardwood , part of the eucalypts range, that grows from Victoria, through the western slopes of NSW, and into southern Queensland.

Red Ironbark heartwood is a deep dark red to red-brown, in contrast its sapwood is a distinctive pale yellow in colour.

Red Ironbark texture is fine and even, with an interlocked grain. It is extremely dense and a very durable species with a susceptibility to surface checking

Red Ironbark is also a Durability Class 1, resistant to termites and suitable for BAL 12.5, 19 and 29 ratings. Other sizes available are 42x19mm, 64x19mm, 135x19mm and 140x22mm

Available by special order from NHS

Sources
www.woodsolutions.com.au
Wood in Australia, Types, properties and uses, Second Edition By Keith R Bootle