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  • Merbau
    "A hardwood built to endure"

    At Durable Hardwoods, we love Merbau - and so do our customers! 
    ​Merbau is one of the world's most trusted external hardwoods and our most popular hardwood. 

    ​It is prized for its extraordinary durability, natural beauty, ​and versatility across every outdoor application and versatility across every outdoor application.

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Merbau doesn't just look beautiful — it performs. From its Class 1 durability rating to its natural resistance to termites and moisture, every characteristic of this remarkable timber makes it purpose-built for the Australian outdoors. When it comes to external hardwood, performance credentials matter — and Merbau consistently ranks among the highest-rated timbers across every key measure, making it the specification of choice for professionals across Australia.

Why we love Mebau!

 Durability Class Treatment LevelTermite & Ant Resistance Heat Resistance Strength, Density, Hardness Moisture Resistance
High High High High High High
Class 1H Rating 4 -5 Natural Bal 29
 F Rating 11 - 14
Jenka rating 8.6 kN
Density 830 kg/m³
 Natural
 Above Ground for 50+ years. In ground rating of 25+ years. Exceptional resistance to decay. Suitable for use in termite-prone areas. Rated highly for in-ground and structural applications in contact with the ground and fresh water. Naturally resistant to termite & ant attack due to high oil content — critical for Australian outdoor structures. Merbau is highly regarded for bushfire-prone areas, meaning it can withstand intense ember attack and moderate-to-high radiant heat. Exceptionally hard, dense, stiff and stable. Resists denting, scratching and heavy foot traffic while delivering high load-bearing capacity. Natural resin oils repel moisture, minimising swelling and shrinkage in wet or coastal environments

What is Merbau?

A Hardwood in a Class of Its Own

Merbau (Intsia bijuga / Intsia palembanica) is a premium tropical hardwood sourced from the tropical forests of Southeast Asia and the Pacific. It has been a cornerstone of outdoor construction across Australia for decades — and for good reason.

Its deep reddish-brown heartwood, interlocked grain, and naturally occurring oils make it uniquely resistant to moisture, insects, and decay. This is a timber that thrives in the harsh Australian climate — coastal salt air, intense UV, and extreme heat included.

At Durable Hardwoods, we source Merbau through our extensive Australian and international mill network, ensuring every piece meets strict quality and sustainability standards.

Applications

Versatile. Dependable. Beautiful.

Merbau's combination of hardness, natural oils, and visual warmth makes it the go-to choice for architects, builders, councils, and landscapers across NSW, Queensland, Victoria, and South Australia.

Decking

Merbau is the benchmark for external decking in Australia. Its hardness resists heavy foot traffic, while its oils provide natural moisture protection, delivering a deck that stays beautiful for decades.

Cladding & Screening

The rich, warm tones of Merbau make it an architect favourite for external cladding and privacy screening. It weathers with character and handles UV exposure exceptionally well.

Fencing & Posts

Merbau fencing & Posts deliver strength and longevity in equal measure. Its Class 1 durability rating makes it suitable for exposed posts and palings in all Australian climate zones.

Landscaping & Retaining

From garden edging to retaining walls and planter boxes, Merbau performs under sustained soil contact and moisture — outlasting treated pine alternatives significantly.

Jetties, Bridges & Walkways

Merbau is widely specified for public boardwalks, bridges, and jetties & Piers — including Council and Government infrastructure — due to its structural strength and resistance to marine environments.

Pergolas & Structures

The high density and structural grade of Merbau make it ideal for pergolas, carports, and feature structures — combining load-bearing performance with natural aesthetic appeal.

Species Characteristics

Understanding what makes Merbau perform so well starts with the timber itself. Here's a closer look at the species characteristics that make it one of Australia's most trusted choices for external hardwood applications.

Merbau timber profile

PropertyDetail
Species NameIntsia bijuga / Intsia palembanica — commonly known as Merbau, Kwila, or Pacific Teak
ColourRich reddish-brown to dark brown, often with golden streaks. Deepens and mellows with age and UV exposure
GrainInterlocked to wavy. Coarse texture with a lustrous surface. Takes a smooth finish well
Working PropertiesMachines well. Carbide-tipped tools recommended. Glues, nails, and screws satisfactorily. Pre-drilling advised
Durability ClassClass 1 (above ground) — highest classification under AS 5604
Janka Hardness8.6 kN — significantly harder than most Australian hardwoods
Density~830 kg/m³ at 12% moisture content
Fire ResistanceBAL–29 compliant under the National Construction Code
Tannin BleedNatural characteristic when first exposed to rain. Reduces over time. Pre-oiling and proper drainage detailing minimises staining
MaintenanceAnnual application of a quality penetrating oil recommended. Will naturally silver-grey if untreated — structural integrity unaffected
SustainabilitySourced from verified, responsibly managed suppliers. Sourcing documentation available on request
Available SizesDecking (90×19, 140×19, 140×45), structural, posts, rails, palings. Custom mill sizes available — contact us for current stock