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Vertically laminated timber is designed to resist bending loads applied parallel to the wide face of the laminations. For vertical loads, this means that the wide face runs vertically.

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Western Australian Blackbutt | Calyptus patens

Western Australian Blackbutt is an Australian hardwood, pale yellowish brown in appearance and used mainly for general construction applications.

Western Australian Blackbutt is a large Australian hardwood often used for general construction applications.

Western Australian Blackbutt is a large Australian hardwood from the forest areas of south west Western Australia. It’s used for general construction, flooring and paneling.

Other Names: WA Blackbutt, Yarri, Swan River Blackbutt

Overview
Properties
Description
Applications

Overview

Western Australian Blackbutt is a large Australian hardwood that grows in the wetter southwest Jarrah and Karri forest areas of Western Australia. It is generally in very limited supply, in part to it growing in reserves.

Also known as Yarri, it is lighter in appearance than Blackbutt Eucalyptus pilularis. The heartwood is a pale yellowish brown, while the sapwood is much paler in appearance.

Western Australian Blackbutt has a medium to course texture and an interlocked grain, which can make this species harder to work. Apart from this it has good workability characteristics. Pinholes may also be present but can sanded or polished out during finishing.

Western Australian Blackbutt is used for general construction applications, flooring and joinery.

Properties

Shrinkage

	Very Low	Low	Medium	High	Very High
Tangential:
Tangential:					10.0
Radial:					> 5

Strength Group

	Very High	High	Reasonably High	Medium High	Medium	Reasonably Low	Low	Very Low
Unseasoned:	S1	S2	S3	S4	S5	S6	S7
Unseasoned:
Seasoned:	SD1	SD2	SD3	SD4	SD5	SD6	SD7	SD8
Seasoned:

Stress Grade

	Structural No. 1	Structural No. 2	Structural No. 3	Structural No. 4	Structural No. 5
Unseasoned:	F14	F11	F8	F7	F5
Seasoned:	F17	F14	F11	F8	F7

Density per Standard

Unseasoned:	1120 kg/m³
Seasoned:	850 kg/m³

Joint Group

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

Colour

White, yellow, pale straw to light brown	Pink to pink brown	Light to dark red	Brown, chocolate, mottled or streaky

Mechanical Properties

Modulus of Rupture - Unseasoned:	66
Modulus of Rupture - Seasoned:	99
Modulus of Elasticity - Unseasoned:	12
Modulus of Elasticity - Seasoned:	13
Maximum Crushing Strength - Unseasoned:	37
Maximum Crushing Strength - Seasoned:	65
Impact - Unseasoned:	13
Impact - Seasoned:	11
Toughness - Unseasoned:	Low - up to 15 Nm
Toughness - Seasoned:	Low - up to 15 Nm
Hardness - Unseasoned:	5.5
Hardness - Seasoned:	6.9

Durability

	Low	Moderate	Reasonably High	High
	(0 - 5 yrs)	(5 - 15 yrs)	(15 - 25 yrs)	(more than 25 yrs)
In-Ground:
	(0 - 7 yrs)	(7 - 15 yrs)	(15 - 40 yrs)	(More than 40 yrs)
Above ground:
	(0 - 20 yrs, usually < 5)	(21 - 40 yrs)	(41 - 64 yrs)	(More than 60 yrs)
Marine Borer Resistance:

Lyctid Borer Susceptibility:	Susceptible
Termite Resistance:	Resistant

Fire Properties

	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
EFH Ignitibility:

	0	1	2	3	4	5	6	7	8	9	10
EFH Spread-of-Flame Index:
EFH Smoke-Developed Index:

	1 - non-combustible	2 - reasonably non-combustible	3 - slightly combustible	4 - combustible
Fire Properties Group Number:

Average Specific Extinction Area:	<250
Bushfire Resistance:	BAL 12.5 and 19 – All AS3959 required applications

Description

Botanical Name:	Calyptus patens
Preferred Common Name:	Western Australian Blackbutt
Other Names:	WA Blackbutt, Yarri, Swan River Blackbutt
Species Type:	Hardwood

Appearance

Western Australian Blackbutt is lighter in appearance than Blackbutt Eucalyptus pilularis. The heartwood is a pale yellowish brown, while the sapwood is much paler in appearance.

It has a medium to course texture and an interlocked grain, whereas other Blackbutt varieties tend to have a straight grain.

Common Applications

Western Australian Blackbutt is used mainly for general construction, flooring and paneling. It is also be used for sleepers.

Common Form

Sawn

Workability

Origin of Timber

Availability - Further Information

Western Australian Blackbutt is in quite limited supply and generally only available in Western Australia.

Source of Timber

Native Forest

Applications

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.
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.
Internal Paneling

Timber paneling creates interiors as warm as they are stylish. Commonly utilising an MDF or plywood substrate, internal timber paneling is natural and versatile and comes as either solid natural timber panels or as sheets of engineered wood products
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.

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