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Spruce-Pine-Fir (SPF)
Spruce-Pine-Fir, or SPF, is the generic name for a variety of softwood species, even-grained and yellowish-white in colour, imported from North America and used in housing construction frames.

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White Mahogany | Eucalyptus acmenoides

White Mahogany is one of Australia’s premium native hardwoods with a high degree of natural durability and strength.

White Mahogany is a premium Australian hardwood used for structural, interior and exterior applications.

Other Names: Yellow Stringybark (Qld), White Stringybark, Narrow-leaved White Mahogany, Eucalyptus Umbra, Eucalyptus tenuipes

Overview
Properties
Description
Applications
Suppliers

Overview

White Mahogany is one of Australia's premium native hardwoods with a high degree of natural durability and strength, making it an ideal timber for a variety of structural, exterior and interior applications.

White mahogany is the common name for four species that grow along the east coast of Australia, from mid-New South Wales to northern Queensland, with isolated pockets north of the Queensland tablelands. Sawn timbers from these species are readily available across Australia. They have straight, slender trunks with rough, fibrous bark that is shed in strips, giving the trees their characteristic stringy appearance and resulting in the common local names of Yellow or White Stringybark.

The species varies in appearance but not in durability class or other properties. The heartwood is light brown to yellow brown in colour. The sapwood is usually creamy brown and is uniformly lighter than the heartwood. White Mahogany wood has a slightly greasy feel, a characteristic that aids machining and boring. It is termite resistant and the sapwood can be easily treated with preservatives. The heartwood is too dense to accept readily available commercial preservation processes.

The wood is used as a sawn timber in engineering applications such as wharf and bridge construction, railway sleepers, cross-arms and mining timbers. It is suitable for a range of building applications, such as posts and poles, framing, flooring, lining, decking and cladding. White Mahogany is also used in the manufacture of veneer and plywood. Other applications include boatbuilding, coach and carriage building, and agricultural machinery.

Properties

Shrinkage

	Very Low	Low	Medium	High	Very High
Tangential:
Tangential:			5.4
Radial:			3 - 4

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:	F27	F17	F14	F11	F8
Seasoned:	F27	F22	F17	F14	F11

Density per Standard

Unseasoned:	1200 kg/m³
Seasoned:	960 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:	101
Modulus of Rupture - Seasoned:	130
Modulus of Elasticity - Unseasoned:	16
Modulus of Elasticity - Seasoned:	17
Maximum Crushing Strength - Unseasoned:	49
Maximum Crushing Strength - Seasoned:	76
Impact - Unseasoned:	17
Impact - Seasoned:	14
Toughness - Unseasoned:	Medium - 15 - 25 Nm
Toughness - Seasoned:	Medium - 15 - 25 Nm
Hardness - Unseasoned:	8.5
Hardness - Seasoned:	10

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:	Not 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:

Group Number - Other:	3 if used on MDF or particleboard ≥12mm; veneer thickness 0.6-0.85mm
Average Specific Extinction Area:	<250
Bushfire Resistance:	BAL 12.5 and 19 – All AS3959 required applications

Description

Botanical Name:	Eucalyptus acmenoides
Preferred Common Name:	White Mahogany
Other Names:	Yellow Stringybark (Qld), White Stringybark, Narrow-leaved White Mahogany, Eucalyptus Umbra, Eucalyptus tenuipes
Species Type:	Hardwood

Appearance

White Mahogany timbers are available in a narrow range of colours. The heartwood is light brown to yellow brown in colour and has a similar appearance to Tallowwood. The sapwood is usually creamy brown, clearly lighter in colour than the heartwood and generally less than 20mm wide.

A mostly uniform and medium textured wood, White Mahogany can sometimes have an interlocked grain. It can also feature distinctive markings caused by moth grub holes and occasional gum veining. It has a slightly greasy feel, although not as greasy as the similarly coloured Tallowwood or Spotted Gum.

Common Applications

White Mahogany is often used for above ground framing and decking in both protected and unprotected contexts. It can also be used for heavy construction work, from sawn and round timber in wharf and bridge construction to railway sleepers, cross arms, poles, piles. and as mining timbers. It is employed in general house framing, as cladding, linings, joinery, fencing, landscaping and in retaining walls. The species is also suitable for use in structural plywood, boat building (keel and framing components, planking), coach, vehicle and carriage building and agricultural machinery. It is often used in internal and external flooring as its hardness means it does not easily dent, and is also frequently used in outdoor furniture due to its durability.

Common Form

Sawn

Workability

White Mahogany machines well due to its natural greasiness, and there is no difficulty using it with standard fittings and fastenings. Due to its hardness, the timber is not easily worked with hand tools. As with other high-density species, machining and surface preparation should be done immediately before gluing. Easily painted, stained, and polished, the sapwood readily accepts preservatives but the density of the hardwood makes it resistant to current commercial preservative compounds.

Origin of Timber

NSW, QLD

Readily Available

NSW, QLD

Availability - Further Information

White Mahogany is an important commercial species in NSW and Queensland.

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.
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.
Shear walls

Lateral loads such as wind or earthquake on framed timber buildings - either post and beam or stud and joist - need to be resisted and shear walls and diaphragms offer an effective and economical solution.
Structural Timber Poles

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 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.
Windows

With natural aesthetic appeal, versatility and sound structural performance, timber provides excellent window joinery design options. Whether stained to bring out natural tones, or painted to compliment particular décors, timber windows can be tailored to suit a huge variety of styles and can be installed into any type of building.