Merbau

Merbau is an orangey to reddish-brown tropical hardwood with a Janka hardness of 1,840 lbf (7,620 N), and Tropix rates it a stable wood¹². The cautions are a water-soluble yellow deposit that can stain and a documented illegal-logging problem in part of its range. Check the species, the origin and the paperwork before you specify it.

What is merbau?

"Merbau" is the trade name for Intsia bijuga and Intsia palembanica, and The Wood Database lists the wood as Intsia spp., also called kwila or ipil¹. Tropix treats Intsia bijuga as the main entry, with Afzelia bijuga among its synonyms, and records local names including merbau in Indonesia and Malaysia, kwila in Papua New Guinea, ipil in the Philippines, vesi in Fiji and kohu in New Caledonia². TRAFFIC names both species as the ones commonly traded⁵.

Where does merbau grow?

The Wood Database says it is native from East Africa through Southeast Asia to Australia, mainly New Guinea, and reaches 40 to 60 m (130 to 200 ft) with a trunk 1.2 to 1.5 m (4 to 5 ft) across¹. Tropix lists Australia, China, Fiji, Indonesia, Madagascar, Malaysia, New Caledonia, Papua New Guinea, the Philippines, Thailand and Viet Nam as main producing countries². The Wood Database describes supply as sporadic, in generous widths and lengths, at a moderate price for an imported hardwood¹.

What does merbau look like?

Freshly cut wood is orangey brown and darkens to reddish brown with age, and colour varies widely between boards¹. Tropix describes heartwood that turns dark red-brown or dark brown with light, with a clearly demarcated sapwood². Grain is straight to interlocked and texture is coarse with moderate natural lustre¹. Both sources mention small yellow deposits, which The Wood Database calls mineral deposits and Tropix calls sulphur deposits¹².

How hard, dense and stable is merbau?

The two databases differ slightly, which is normal for a wood that, as Tropix warns, can vary significantly with origin and growing conditions¹². Tropix classes merbau as stable wood, with a slow drying rate and a slight risk of distortion and checking². For how to read the hardness figure, see Janka hardness explained, and compare other species on the hardness chart. Whatever the species, moisture and acclimatisation still apply.

Can merbau stain, and does it affect finishing?

The Wood Database says the small yellow mineral deposits throughout the wood are water-soluble and can cause staining¹. Tropix lists a risk of dripping from tannin-type coloured chemical compounds, which can cause aesthetic damage to nearby structures². Neither source tests how this interacts with a particular floor finish, so ask your supplier how the product was treated and read the wood floor finishes guide.

On workability, The Wood Database says merbau glues and finishes well, but that sawing can be difficult because the wood gums up and dulls saw teeth, and that sawing or sanding gives off a distinctive smell that can irritate¹. Tropix rates nailing and screwing as good but with pre-boring necessary, notes a tendency to split, and advises following the glue maker's instructions because of the high density².

Is merbau used for flooring?

Yes. The Wood Database lists flooring first among its common uses, and Tropix lists flooring and industrial or heavy flooring among end-uses, alongside decking and interior joinery¹². Tropix rates the heartwood as durability class 1-2 against fungi, and as not permeable to preservative². See solid wood flooring for how such boards are made, and teak for another tropical floor timber.

Is merbau a protected or threatened species?

CITES. Tropix states that merbau is not listed in the CITES Appendices (Washington Convention, 2025), and The Wood Database also says it is not listed²¹. We could not open the Species+ database itself, so check the current appendices for any purchase.

IUCN. Sources disagree, and we could not open the IUCN assessment page. The Wood Database says the IUCN Red List classes it as Vulnerable, citing a population decline of over 20% in three generations from range loss and exploitation¹. A 2022 paper in the Journal of Threatened Taxa says Intsia bijuga is categorised Near Threatened and has been on the Red List since 1998, and says its range in Indonesia has shrunk to Papua and Maluku⁴. Treat the category as unconfirmed here, and look up the current assessment.

What are the illegal logging concerns?

This section reports what named bodies found, and does not claim all merbau is illegal.

• Indonesia. EIA and Kaoem Telapak write that illegal loggers and traders have particularly focused on high-value species such as merbau. Their 2017 investigation covered illegal merbau logging in Papua and West Papua and its trade to Surabaya³. They estimate roughly 50% of Indonesian merbau timber product exports go to China, where uses include flooring³.
• Enforcement gaps. The same report found inconsistent enforcement. It says some companies found guilty of trading illegal timber still held a SVLK legality certificate, and describes a concern that illegal merbau can be "greenwashed" into the legal supply chain³.
• Papua New Guinea. A Global Witness presentation (2017) quotes Chatham House (April 2014) as concluding that the majority of PNG timber production is illegal in some way⁶. That is a country-wide finding, not a merbau-specific one, though PNG is a main producing country for merbau².

What due diligence applies to buyers?

In general terms, the rules turn on legal origin.

• United States. APHIS says it is against the law to import any illegally harvested plant or plant product under the Lacey Act. Importers file a declaration, and are advised to learn each plant's scientific name and where it was harvested⁸.
• European Union. The Commission says the Deforestation Regulation requires operators placing wood on the market to show that it was produced in line with the laws of the country of production and does not originate from land deforested after 31 December 2020. It also requires a due diligence statement including the plot's geolocation, and it replaces the EU Timber Regulation⁷. The Commission's page records postponements, with application dates of 30 December 2026 for large and medium operators, so confirm the current dates⁷.

Ask any supplier for the species name, country and region of harvest, and the legality documents they hold. Read the full texts, since this page is not legal advice.

How does merbau compare with other floor timbers?

Our teak page gives that species' own cited hardness for comparison with merbau's 1,840 lbf (7,620 N)¹. Hardness is only one factor: stability, finishing and sourcing matter too. Pair merbau with the moisture and acclimatisation advice, and consider whether engineered construction suits the room.

This page compiles published data from the sources listed above. Read our editorial policy. Last updated 4 Nov 2026.