Follow us
Account Login

Email

Password

Forgot your password?
Free Sign Up

2011 WoodSolutions Seminar Presentation available now

Featured Project

Where Preservation Meets Innovation

View more inspiration
General Resources
Why Wood Articles
What is...

Air-dried timber
Timber that is dried by exposure to air in a yard or shed, without artificial heat (also see seasoning).

Visit Glossary

Merbau | Insia Bijuga

Merbau is a popular hardwood that varies in appearance from yellow to orange-brown to dark red.

Merbau is a popular hardwood from South East Asia used in a wide variety of applications from construction to indoor and outdoor furniture.

Other Names: Kwila, Ipil, Vesi, Johnstone River Teak or Scrub Mahogany

Overview
Properties
Description
Applications
Suppliers

Overview

Merbau is a popular hardwood derived largely from areas in South East Asia, Papua New Guinea, the Pacific islands, and northern Queensland. With its high degree of natural durability and strength it is appreciated for external applications in rugged engineering, construction and marine contexts. Merbau also features in backyards as outdoor furniture, and internally across a range of joinery, flooring and other uses.

In its natural setting across North Queensland, Malaysia, Fiji, Vietnam, the Philippines, Madagascar, Papua New Guinea, Thailand, Solomon Islands, New Caledonia, Vanuatu and Samoa, the Merbau species can grow up to 40 metres in height, with a 0.6 metre trunk diameter. The bushy tree, with distinctive local names, will often form a spreading canopy.

The attractive yellow-orange brown hue of freshly cut heartwood deepens or reddens with ageing. This contrasts markedly with the Merbau sapwood, which is white, pale yellow or buff coloured. If left untreated, the sapwood is susceptible to lyctid borer attack. Beyond that, Merbau is quite resistant to termites and seasons well with kiln or air-drying, exhibiting only a low degrade and very little shrinkage or movement. The wood grain of the Merbau can vary but it is usually interlocked or wavy, with a coarse but even texture, often prized for its attractiveness on backsawn material. It will finish well with paint, stain, and polish although gum bleed is a possibility.

Merbau is a versatile wood product. It is utilised for larger-scale projects and general construction, along with common use for outdoor settings and barbeque trolleys, and for joinery, flooring and fitting purposes. As it turns well and responds to hand tools it can be applied to more specialised work, such as cabinet making, musical instruments, boat building, carving and tool handles.

Properties

Shrinkage

	Very Low	Low	Medium	High	Very High
Tangential:
Tangential:	2.5
Radial:	0 - 2

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:	1150 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:	103
Modulus of Rupture - Seasoned:	130-147
Modulus of Elasticity - Unseasoned:	15-18
Modulus of Elasticity - Seasoned:	12-18
Maximum Crushing Strength - Unseasoned:	55
Maximum Crushing Strength - Seasoned:	63-81
Impact - Unseasoned:	18
Impact - Seasoned:	7.7-14
Toughness - Unseasoned:	Medium - 15 - 25 Nm
Toughness - Seasoned:	Medium - 15 - 25 Nm
Hardness - Unseasoned:	7.6
Hardness - Seasoned:	7.2-8.6

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, 19 and 29 – All AS3959 required applications

Description

Botanical Name:	Insia Bijuga
Preferred Common Name:	Merbau
Other Names:	Kwila, Ipil, Vesi, Johnstone River Teak or Scrub Mahogany
Species Type:	Hardwood

Appearance

In its natural setting the Merbau species can grow up to 40 metres in height, with a trunk of 0.6 metres in diameter. The bushy tree will often form a spreading canopy. Once cut, the heartwood will initially appear as yellowish-brown or orange-brown before deepening to a pale to dark reddish brown. This contrasts with the Merbau sapwood, which appears white, pale yellow or buff. The wood grain is variable but usually interlocked or wavy, which produces a ribbon figure on the radial surface. The timber has a coarse but even texture. It has a characteristic oily odour when cut.

Common Applications

Merbau spans a variety of uses in the fields of engineering, construction, marine and furnishings, both for the indoors and outside. It has been utilised for infrastructure projects including cross arms, bridge building, piles, sleepers, posts, wharves and mining timbers. In the construction context Merbau is used in framing, decking, treads and other general needs. Many boats, particularly the decks, are made of Merbau, as are a variety of vats, musical instruments and tool handles. As a furniture product Merbau is prominent in outdoor settings and barbeque trolleys, as well as being valued for turning, paneling, joinery, shop fitting, cabinet making, parquet flooring, carving, veneer, counter and bench tops.

Common Form

Sawn, Veneer

Workability

Merbau takes well to paint, stain and polish, however the finish can sometimes be affected by gum bleed-through or oily patches. Its vessels also contain a yellow substance that stains textiles and concrete. It turns well and is relatively easy to work with hand tools, though it can be variable when it comes to machining. It will generally cut cleanly but there may be some blunting or gumming effect on the cutting edges. Merbau tends to split unless pre-bored, but holds fastenings well.

Origin of Timber

QLD, Asia, SE Asia, Oceania

Availability - Further Information

Merbau grows naturally in South East Asia, the Philippines, Solomon Islands, Fiji and Papua New Guinea and is imported to Australia from these countries.
Merbau grows in Australia in a specific region by the Johnstone River and in the Daintree area of Far North Queensland. It is often referred to as Johnstone River Teak or Scrub Mahogany.

Source of Timber

Native Forest, Plantation

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.
Exterior Stairs

For outdoor applications, timber is one of the leading material choices. Timber use in external staircase applications creates structures of strength and durability, sheathed in a natural beauty that blends seamlessly with the outdoor environment.
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.
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 Joinery Products

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