Buyer's Guide to Timber Decking

Merbau timber is an imported species from Indonesia. It is an extremely stable hardwood decking ideal for high moisture or minimal ventilation applications.
If you are using Merbau decking, it is important to design your deck around its high tannin content to avoid staining paving or concrete.

Timber Properties
• Bushfire Rating BAL29
• Durability Class 1 above ground
• More than 40 years above ground
• 5-15 years in-ground
• Natural resistance to termites
• High tannin content
• Hardness 8.5 Janka Rating

Available sizes
• 70x19mm, 90x19mm, 140x19mm
• Available in random lengths and set lengths (2.1 – 4.2m)

Colour & Grain
• Merbau heartwood is yellowish-brown or orange-brown buts deepens to a pale to dark reddish brown
• The sapwood is white or pale yellow
• Timber grain is usually interlocked or wavy
• Merbau has a coarse but even texture

Installation
• Readily accepts paints, stains and polishes
• Easy to work with
• Tends to split if not pre-drilled
• Holds fasteners well

Top tips
• Use a tannin remover or decking cleaner prior to sealing your Merbau decking to reduce tannin leaching.

Blackbutt timber is an Australian hardwood species found in coastal regions from southern New South Wales to southern Queensland. Blackbutt decking is an extremely strong and durable hardwood ideal for bushfire prone areas.

Timber Properties
• Bushfire Rating BAL29
• Durability Class 1 above ground
• More than 40 years above ground
• 15-25 years in-ground
• Natural resistance to termites
• Hardness 8.9 Janka Rating

Available sizes
• 65x19mm, 86x19mm, 130x19mm, 135x19mm, 135x32mm
• Available in random lengths and set lengths

Colour & Grain
• Blackbutt heartwood ranges from golden yellow to pale brown, sometimes with a slight pinkish colour
• The sapwood is much paler than the heartwood
• Timber grain is usually straight but can be interlocked
• Blackbutt decking has a uniform texture with some small visible gums and pin holes

Installation
• Readily accepts stains and polishes, however painting is not recommended
• Tendency to surface check and split
• Blackbutt decking is easy to work with
• Machines Well
• Holds fasteners well

Top tips
• The high extractives and tannin in mature blackbutt timber, can cause some issues with adhesives and staining on surfaces when it becomes wet.

Cumaru timber is an imported hardwood species from northern South America and parts of Central America. With the highest durability level of any wood species, Cumaru decking is naturally resistant against termites and rot, making for a long-lasting deck, even in rainy conditions.

Timber Properties
• Bushfire Rating BAL19
• Durability Class 1
• More than 40 years above ground
• More than 25 years inground
• Natural resistance to termites
• Low tannin levels

Available sizes
• 90x21mm, 140x21mm
• Cumaru decking is available in random lengths

Colour & Grain
• Cumaru heartwood ranges from medium to dark brown, sometimes with a reddish or purplish colour
• The sapwood is yellowish-brown in colour
• Timber grain is usually interlocked
• Cumaru timber has a medium texture with a waxy feel

Installation
• Readily accepts paints, stains and polishes
• Cumaru decking can be surface planed to a smooth finish
• Due to the high density of the timber, it must be pre-drilled
• Machines Well
• Holds fasteners well

Top tips
• Cumaru decking has very low tannin levels and experiences near-zero leaching, ideal for decking designs that incorporate paving, concrete or rendered areas.

Grey Box timber is a highly dense and durable Australian hardwood decking. It originates from the central and north coast of New South Wales and southern Queensland, including parts of Victoria and South Australia.

Timber Properties
• Bushfire Rating BAL19
• Durability Class 1
• More than 40 years above ground
• More than 25 years inground
• Natural resistance to termites
• Hardness 15 Janka Rating

Available sizes
• 86x19mm, 135x19mm
• Grey Box decking is available in random lengths

Colour & Grain
• Grey Box heartwood is a pale brown to yellowish brown
• The sapwood is paler in colour than the heartwood
• This timber has a clean, interlocked grain
• Grey Box has a fine, even texture

Installation
• Readily accepts paints, stains and polishes
• This dense decking is difficult to work
• Pre-drilling is recommended
• Grey Box decking machines and dresses well

Top tips
• Grey Box decking is particularly sort after in high traffic areas due to its incredibly dense and durable properties.

Grey Ironbark timber is native Australian species found in coastal regions of NSW and southern Queensland. It is one of the hardest and heaviest hardwood timbers, making Grey Ironbark decking ideal for use in commercial, industrial and residential settings.

Timber Properties
• Bushfire Rating BAL19
• Durability Class 1
• More than 40 years above ground
• More than 25 years inground
• Natural resistance to termites
• Hardness 16 Janka Rating

Available sizes
• 86x19mm, 135x19mm
• Grey Ironbark decking is available in random lengths

Colour & Grain
• Grey Ironbark heartwood is light grey or light chocolate with some dark reds and browns
• The sapwood is a distinct, mostly white colour
• Timber grain is usually tight and straight, and only occasionally interlocked
• Grey Ironbark has a moderately coarse and even texture

Installation
• Readily accepts paints, stains and polishes
• Grey Ironbark decking is not easily worked due to its density
• Pre-drilling is recommended
• Holds fasteners well

Top tips
• Grey Ironbark decking is slow drying and needs to be carefully handled to prevent surface checks. Dressed surfaces may result in a steely sheen.

Jarrah timber native hardwood timber from the south-western corner of Western Australia. It is an extremely stable hardwood decking with a good resistance to weather and rot.

Timber Properties
• Bushfire Rating BAL19
• Durability Class 2
• 15 – 40 years above ground
• 15-25 years in-ground
• Natural resistance to termites
• Hardness 8.5 Janka Rating

Available sizes
• 65x19mm, 86x19mm, 135x19mm
• Jarrah decking is available in random and set lengths

Colour & Grain
• Jarrah heartwood is dark red to browns
• The sapwood is usually pale yellow to orange
• This timber usually has a wavy, interlocking grain with a fiddleback pattern
• Jarrah has a moderately coarse but even texture

Installation
• Readily accepts paints, stains and polishes
• Jarrah decking is easy to work with
• Pre-drilling is recommended due to its density
• Holds fasteners well

Top tips
• Jarrah decking machine and turns well, however, a planer blade angle of 15° usually gives the best surface quality.

Spotted Gum timber is a native Australian species found in NSW and northern Victoria, and also in northern and southern Queensland. It is a very durable hardwood with a low tannin content making it a popular choice for areas surrounded by paving or brickwork.

Timber Properties
• Bushfire Rating BAL29
• Durability Class 1 (Above Ground)
• More than 40 years above ground and 15-25 years inground
• Naturally resistant to termites
• Low tannin content
• Hardness 10.1 Janka Rating

Available sizes
• 86x19mm, 135x19mm, 135x32mm (QLD Spotted Gum)
• 86x19mm, 64x19mm (NSW Spotted Gum)
• Spotted Gum decking is available in random lengths and set lengths

Colour & Grain
• Spotted Gum heartwood is light brown to deep red-brown, depending on source
• The sapwood is white to light brown
• Spotted Gum decking offers a wavy grain, often with an attractive fiddleback pattern
• This timber is moderately coarse with an uneven texture

Installation
• Readily accepts paints, stains and polishes
• Spotted Gum decking holds fasteners well
• Pre-drilling is recommended
• Machines well due to its natural greasiness

Top tips
• Spotted Gum decking comes in a wide variety of colours based on the location the timber is sourced from. However, figure in the grain is consistent throughout the species, providing character and interest.

Silvertop Ash timber is an Australian hardwood that grows in New South Wales, Victoria and Tasmania. This moderately durable hardwood is sort after for its gum veins, pinholes and pencil streaks, giving it character. Silvertop Ash decking is a moderately durable hardwood that is prone to surface checking and is inclined to splinter.

Timber Properties
• Bushfire Rating BAL29
• Durability Class 2 (Above Ground)
• 15 – 40 years above ground
• 5-15 years in-ground
• Natural resistance to termites
• Hardness 9.7 Janka Rating

Available sizes
• 65x19mm, 86x19mm, 135x19mm
• Silvertop Ash decking is available in run-of-mill (ROM)

Colour & Grain
• Silvertop Ash heartwood brown and sometimes pinkish in colour
• The sapwood is narrow and often hard to distinguish from heartwood
• Timber grain is interlocked with growth rings
• Silvertop Ash has a medium texture

Installation
• Readily accepts paints, stains and polishes
• Silvertop Ash decking is easy to work with
• Machines well
• Excellent for nailing and screwing

Top tips
• Silvertop Ash is often a run-of mill timber grade which means it includes natural feature as well as medium feature.

Tallowwood timber is an Australian native hardwood species found in coastal regions of NSW and Queensland. Tallowwood decking is an extremely dense and hard timber, yet relatively easy to work with due to its natural greasiness.

Timber Properties
• Bushfire Rating BAL19
• Durability Class 1
• More than 40 years above ground
• More than 25 years in-ground durability
• Natural resistance to termites
• Hardness 8.6 Janka Rating

Available sizes
• 86x19mm, 135x19mm
• Tallowwood decking is available in random lengths and set lengths

Colour & Grain
• Tallowwood heartwood is pale to dark yellow-brown, with tinges of olive green
• The sapwood is off-white
• Timber grain is usually interlocked, free from gum veins
• Tallowwood has a moderately coarse texture with a ‘greasy’ appearance

Installation
• Readily accepts paints, stains and polishes
• Tallowwood decking is easy to work with
• Pre-drilling is recommended for nailing and screwing
• This timber machines and turns easily

Top tips
• Tallowwood decking is highly resistant to decay and can withstand damp and wet conditions well.

Pine timber is a softwood species readily available from Australian Pine plantations. Treated Pine decking is extremely easy to work with and is H3 treated to increase durability and protect it from termites and decay. Treated Pine decking knots contain a high resin content and can mar paints and stains applied to these areas.

Timber Properties
• Bushfire Rating BAL12.5
• H3 Treated Hazard Level
• 25 years warranty above ground
• H3 Treated for protection against decay and termites
• High resin content in knots

Available sizes
• 70x22mm, 90x22mm
• Treated Pine decking is available in set lengths

Colour & Grain
• Pine heartwood is light brown to yellow
• The sapwood is white or pale yellow
• Treated Pine grain is usually straight but knots are common
• Pine decking has a fine yet uneven texture

Installation
• Readily accepts paints, stains and polishes
• Treated Pine decking is very workable, except for the knots
• Does not require pre-drilling
• Holds fasteners well

Top tips
• Without the correct protective coating, pine decking is susceptible to surface checking when exposed to the weather.