Grey Ironbark (Eucalyptus Paniculata)

Grey Ironbark is a premium native Australian hardwood with a wide range of applications from industrial construction to house framing, flooring and sporting goods.

Grey Ironbark is a premium native hardwood that has been well regarded as a high quality timber in Australia throughout human history. Indigenous Australians use it to make spear throwers and boil its bark for treating sores. It is a particularly hard, strong and durable timber, with a truly broad range of applications, due to its resistance to lyctid borers and termites.

The Grey Ironbark is a medium sized tree of 30 to 50m with a stem diameter of 1.5m. The bark is hard, coarse, with deep furrows and ridges, ranging from dark brown to black in colour and grows from northern New South Wales to Bundaberg, Queensland. It is also found in scattered patches as far north as the Atherton Tableland.

A very heavy timber, at 1120 kilograms per cubic metre, Grey Ironbark is dense and can be difficult to work. Dressed surfaces take on a steely sheen. The timber’s appearance ranges from reddish to dark brown heartwood. The sapwood is lighter in colour and is 20mm thick on average. Grain is usually tight and straight and no distinctive figure is encountered.

Both sawn and round grey ironbark timber has a wide range of applications. Engineering uses include railway sleepers, construction, poles and cross-arms, and bridge construction. Unseasoned timber is used in house framing, while dressed timber can be employed for both internal and external use. It has also been used in boat, coach, vehicle and carriage building and to create sporting goods.

Botanical Name:

    Eucalyptus paniculata

Common Name:

    Ironbark

AKA:

    White Ironbark, Eucalyptus drepanophylla, Eucalyptus siderophloia, Eucalyptus decepta

Type:

    Hardwood

Appearance

Grey Ironbark sapwood is almost white, making it highly distinct from the heartwood, which ranges from light grey or light chocolate with darker reds and browns sometimes occurring. The timber’s texture is moderately coarse and even, and the grain usually straight, and only occasionally interlocked. Grey Ironbark may have regional variations in timber colour, with some timbers having black narrow to broad streaks running through the timber.

Common Applications

Due to its class 1 strength and durability ratings, Grey Ironbark is commonly used in engineering applications as a sawn and round timber. It can be used for wharf and bridge construction, railway sleepers, cross arms, poles, piles and mining timbers. The unseasoned timber is excellent for general house framing, while seasoned and dressed grey ironbark timber is used for cladding, internal and external flooring, linings and joinery. It is also ideal for fencing, landscaping and retaining walls.

Grey Ironbark can also be used for aesthetic purposes such as in outdoor furniture, turnery and joinery, although it is hard to work in applications requiring fine detail.

The timber’s versatility extends to boat building (keel and framing components, planking), including reputed use in the hulls of early ice-breaker ships. Coach, vehicle and carriage building, agricultural machinery, mallet heads, mauls and bearings, sporting goods (croquet mallets, parallel bars) and bowling ninepins have all been produced using Grey Ironbark.

Common Form

Sawn

Workabiity

Due to its class 1 strength and durability ratings, Grey Ironbark is commonly used in engineering applications as a sawn and round timber. It can be used for wharf and bridge construction, railway sleepers, cross arms, poles, piles and mining timbers. The unseasoned timber is excellent for general house framing, while seasoned and dressed grey ironbark timber is used for cladding, internal and external flooring, linings and joinery. It is also ideal for fencing, landscaping and retaining walls.

Grey Ironbark has been employed for decorative purposes such as in outdoor furniture, turnery and joinery, although it is hard to work in applications requiring fine detail.

The timber’s versatility extends to boat building (keel and framing components, planking), including reputed use in the hulls of early ice-breaker ships. Coach, vehicle and carriage building, agricultural machinery, mallet heads, mauls and bearings, sporting goods (croquet mallets, parallel bars) and bowling ninepins have all been produced using grey ironbark.

Decking

Timber decking creates spaces that are functional, practical and aesthetically pleasing. With the right design and care a timber deck will make a valuable addition to any home or business, creating an outdoor living space that will be enjoyed for years to come.

External Cladding

The natural appeal, versatility and strength of timber makes it the superior choice for external cladding. Through specification, planning, design and finishing processes, timber cladding not only creates a building of superior strength, acoustic and thermal performance but also creates a place of beauty, style and natural appeal.

Flooring

Whether for structural or finished flooring applications, timber offers durability, versatility and adaptability. The warmth, strength and natural beauty of timber flooring has proved enduringly popular in a wide variety of interior settings.

Framing

Since people began building simple shelters, wooden framing has played an important role in shaping structures of many kinds. One of the most popular types of wooden framing is known as lightweight timber construction.

Retaining Walls & Landscaping

When it comes to retaining wall, landscape design and construction, timber is the natural choice. A material that is durable, sturdy and reliable, it boasts natural aesthetics that help it blend seamlessly with the outdoors. Careful consideration during the specification and design process will facilitate the creation of a long lasting, durable and eye catching timber retaining wall that will complement its surrounding landscape for years to come.

Structural Timber Posts

Timber poles are utilised in structural construction to provide support for gravity loads and resistance against lateral forces. Not only serving a structural function, timber poles provide many aesthetic benefits, with their use in construction often complementing architectural designs aimed at harmonisation with the natural environment.

Timber Joinery Products

Timber joinery products offer a classic, unique and stylish touch to any interior design.

Timber Mouldings

Mouldings are extremely versatile and durable, enhancing the aesthetics of any interior and functioning as the icing on the cake for designs with a focus on beauty and splendour.

Timber Portal Frames

For buildings that require large spans and column free interiors, timber portal frames provide one of the most aesthetically pleasing solutions. Utilising modern engineering technology, portal frame design transforms timber into a highly effective, efficient and economical structural product. This application guide provides a comprehensive overview of the process of using timber in the specification, fabrication and erection of portal frame structures.

SHRINKAGE

Very Low Low Medium High Very High
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Tangential tooltip
7.5
Radial tooltip
4-5
Unit Movement tooltip
0.39%

STRENGTH GROUPS

Very High High Reasonably High Medium High Medium Reasonably Low Low Very Low
Uneasoned
S1
S2
S3
S4
S5
S6
S7
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Seasoned
SD1
SD2
S3
SD4
SD5
SD6
SD7
SD8
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STRESS GRADE tooltip

Structural No 1 Structural No 2 Structural No 3 Structural No 4 Structural No 5
Unseasoned
F22
F22
F17
F14
F11
Seasoned
F34
F34
F27
F22
F17

DENSITY PER STANDARD tooltip

Unseasoned 1210kg/m3
Seasoned 1090kg/m3

JOINT GROUP tooltip

Very High High Reasonably High Medium Low Very Low
Unseasoned
J1
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J2
J3
J4
J5
J6
Seasoned
JD1
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JD2
JD3
JD4
JD5
JD6

COLOUR tooltip

White, Yellow,Pale Straw to Light Brown Pink to pink brown Light to dark red Brown, chocolate, mottled or streaky
Shade species_colour_bar_sm
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MECHANICAL PROPERTIES

Modulus of Rupture – Unseasoned tooltip
120
Modulus of Rupture – Seasoned tooltip
181
Modulus of Elasticity – Unseasoned tooltip
20
Modulus of Elasticity – Seasoned tooltip
24
Maximum Crushing Strength – Unseasoned tooltip
60
Maximum Crushing Strength – Seasoned
95
Impact – Unseasoned tooltip
24
Impact – Seasoned tooltip
27
Toughness – Unseasoned tooltip
High – 25 Nm and above
Toughness – Seasoned tooltip
High – 25 Nm and above
Hardness – Unseasoned tooltip
11
Hardness – Seasoned tooltip
14

DURABILITY

Low Moderate Reasonably High High
(0-5 years)
(5-15 years)
(15-25 years)
(> 25 years)
In Ground tooltip tick
(0-7 years)
(7-15 years)
(15-40 years)
(>40 years)
Above Ground tooltip
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(0-20 years, usually <5) (21-40 years) (41-64 years) (>65 years)
Marine Borer Resistance tooltip
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Lyctid Borer Susceptibility tooltip
Not Susceptible
Termite Resistance tooltip
Resistant

FIRE PROPERTIES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
EFH Ignitability tooltip
fire_arrow
fire_m
EFH Spread of Flame Index tooltip
1
2
3
4
5
6
7
8
9
10
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fire_m
EFH Smoke Developed Index tooltip
1
2
3
4
5
6
7
8
9
10
fire_arrow
fire_m
Critical Radiance Flux – Lower tooltip
>2.2 and <4.5kWm 2
Critical Radiance Flux – Higher tooltip
> 4.5kWm 2
Smoke Development Rating tooltip
<750
Fire Properties Group Number tooltip
1 – Non Combustible
2 – reasonably non combustible
3 – slightly combustible
4 – combustible
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fire_m
Average Specific Extinction Area tooltip
<250
Bushfire Resistance tooltip
BAL 12.5, 19 and 29 – All AS3959 required applications