Blackbutt (Eucalyptus Pilularis)

Blackbutt is an Australian hardwood that is commonly used for stuctural and exterior applications.

The name Blackbutt came about due to the tree’s appearance after bushfire, whereby the buttress – or butt – was significantly darkened. It is also known as Coastal Blackbutt to distinguish it from the tableland species, New England Blackbutt.

Due to its quick growth and versatility, Blackbutt makes a good plantation timber. It is a commonly available commercial hardwood species in New South Wales and southern Queensland, often used for building framework.

The heartwood ranges from golden yellow to pale brown, although occasionally a slight pinkish colour may be present. The sapwood, which is not always easy to distinguish, is much paler in appearance and is resistant to attack by lyctid borer. Blackbutt has an even texture and generally straight grain making it appealing for interior use applications.

Blackbutt can be stained, painted or polished but there can be issues with painting because of its tendency to surface check. The high extractives of mature wood can cause problems with some adhesives, but this is much less of an issue with young regrowth wood. These extractives can also cause staining on painted surfaces exposed to the weather. Blackbutt machines well but is only fair for steam bending.

Blackbutt has been found to be suitable (by the Building Commission in Victoria) for home construction in bushfire areas (provided it has a thickness greater than 18mm).

A strong, durable hardwood, Blackbutt can be used for a range of structural, exterior and interior applications including framework, decking, flooring and poles.

Botanical Name:

    Eucalyptus pilularis

Common Name:

    Blackbutt

AKA:

    Coastal Blackbutt, Pink Blackbutt

Type:

    Hardwood

Appearance

Blackbutt has an even texture. The grain can be interlocked but it is generally straight, making it appealing for interior use applications such as flooring and joinery. The heartwood ranges from golden yellow to pale brown, although occasionally a slight pinkish colour may be present. The sapwood, which is not always easy to distinguish, is much paler in appearance. Small gum veins may also be visible.

Common Applications

Blackbutt is a versatile timber and is used for structural, exterior and interior applications. In New South Wales and southern Queensland it is very popular for timber framing but is also used for cladding, internal and external flooring, decking, joinery, landscaping and furniture. Blackbutt is also used in the manufacture of plywood.

Common Form

Sawn

Workabiity

Care needs to be taken when drying as Blackbutt is prone to surface checking on the tangential surface. Blackbutt should not be re-conditioned as this will widen any surface checks. Blackbutt can be stained, painted or polished but there can be issues with painting because of its tendency to surface check. The high extractives of mature wood can cause problems with some adhesives, but this is much less of an issue with young regrowth wood. These extractives can also cause staining on painted surfaces after exposure to the weather. Blackbutt machines well but is only fair for steam bending.

Architectural Roof Trusses

Architectural timber roof trusses create strong visual impact. Often used as part of ‘cathedral ceiling’ systems, timber can be specified light or heavy to suit the chosen theme and style. On finish, they can be left natural or may be oiled, stained, painted or highly decorated. Choice is limited only by individual style and design preferences.

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.

Interior Rails and Balustrades

With its natural beauty and inherent strength, timber is a popular material choice in internal balustrade construction. Commonly built from treated softwoods and durable hardwoods, interior balustrades and handrails are typically finished with a clear lacquer to generate the most natural result.

Interior Stairs

Timber should be the material of choice for designers seeking internal staircases of strength, beauty and durability. The construction procedure described here applies to most general type stairs of either conventional or contemporary construction.

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
 7.3
Radial tooltip
 4-5
Unit Movement tooltip
 .37%

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
tick

STRESS GRADE tooltip

Structural No 1 Structural No 2 Structural No 3 Structural No 4 Structural No 5
Unseasoned
F27
F17
F14
F11
F8
Seasoned
F34
F27
F22
F17
F14

DENSITY PER STANDARD tooltip

Unseasoned 1100kg/m3
Seasoned 880kg/m3

JOINT GROUP tooltip

Very High High Reasonably High Medium Low Very Low
Unseasoned
J1
J2
tick
J3
J4
J5
J6
Seasoned
JD1
JD2
tick
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
100
Modulus of Rupture – Seasoned tooltip
144
Modulus of Elasticity – Unseasoned tooltip
17
Modulus of Elasticity – Seasoned tooltip
19
Maximum Crushing Strength – Unseasoned tooltip
48
Maximum Crushing Strength – Seasoned
77
Impact – Unseasoned tooltip
21
Impact – Seasoned tooltip
22
Toughness – Unseasoned tooltip
Medium – 15 – 25 Nm
Toughness – Seasoned tooltip
Medium – 15 – 25 Nm
Hardness – Unseasoned tooltip
7.3
Hardness – Seasoned tooltip
9.1

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
tick
(0-20 years, usually <5) (21-40 years) (41-64 years) (>65 years)
Marine Borer Resistance tooltip  tick
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
 fire_arrow
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
>2.2 and <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
fire_arrow
fire_m
Average Specific Extinction Area tooltip
<250
Bushfire Resistance tooltip
BAL 12.5, 19 and 29 – All AS3959 required applications