What is iroko hardwood?
The Wood Guide · The wood register
Tropical hardwood · referenceIroko
Also sold as kambala. An African hardwood that comes close to the durability of teak, with a warm golden-brown colour that darkens over the years.
- Chlorophora regia · excelsa
- ±650 kg/m³
- Heartwood class I–II
IrokoMilicia excelsa
Iroko at a glance
Iroko has been earning its stripes in construction, joinery and the furniture industry for decades. If you are looking for a hardwood that can cope with our weather without intensive maintenance, you soon end up with it.
The wood combines impressive natural durability with a warm, golden-brown look that darkens to dark brown on exposure to air. At around 650 kg per cubic metre it is sturdy without being leaden — a pleasant middle ground between teak and the really heavy tropical species.
Iroko is often called "poor man's teak". That sells it short: the durability is comparable, the price a good deal friendlier, and the only real difference is that iroko contains less natural oil.
The heartwood reaches class I to II, but the yellowish-white sapwood is in class V — not durable. For construction and outdoor work only heartwood is therefore used. Ask for it explicitly.
- Botanical
- Chlorophora regia and C. excelsa
- Heartwood
- golden brown, darkens to dark brown
- Sapwood
- yellowish white, not durable
- Density
- ±650 kg/m³
- Outdoors
- class I–II (heartwood)
- Maintenance
- none; greys without loss
To be fair: iroko contains hard calcium deposits that damage saw blades and chisels, and with interlocked grain it can tear out. Sharp carbide tooling is no luxury.
Heartwood only
The golden-brown heartwood reaches durability class I to II, but the yellowish-white sapwood is in class V — not durable. For construction and outdoor work only heartwood is therefore used. Ask for it explicitly.
Click a chapter or use the arrows · ranges and cross-sections schematic.
Where iroko comes from
The trade name covers two botanical species, both belonging to the genus Chlorophora.
Chlorophora regia
Grows in the wet rainforests of West Africa, from Gambia to Ghana — mainly in coastal areas with high rainfall.
Chlorophora excelsa
Has a much larger range, from Senegal to Mozambique, and copes better with dry periods.
In practice
Both produce wood with comparable properties and are rarely told apart. You simply buy "iroko".
As a tropical hardwood from African rainforest, forestry practice is a real point of attention. Ask your supplier where the wood comes from. If you are looking for a European alternative with comparable durability, look at robinia.
Technical properties
| Property | Description |
|---|---|
| Colour and texture | Golden-brown heartwood that turns dark brown in the air; yellowish-white sapwood. Moderately fine grain, straight to interlocked |
| Density | Average ±650 kg/m³ — sturdy without being leaden |
| Durability heartwood | Class I–II — durable to very durable, highly resistant to rot and fungi |
| Durability sapwood | Class V — not durable; not used for outdoor work |
| Workability | Good, by machine and by hand; use adapted cutting angles with interlocked grain |
| Distinctive | May contain hard calcium deposits that damage tools |
Iroko can have stone-hard calcium deposits in the wood. They are rare but notorious: they can ruin a saw blade in one pass. Anyone working a lot of iroko allows for them.
What iroko is used for
Exterior joinery
Windows, doors and frames — the classic use, thanks to its combination of durability and dimensional stability.
Garden furniture
Tables and benches that can stand outdoors for decades without treatment.
Decking and cladding
Greys evenly to silver grey, just like teak.
Laboratory worktops
A lesser-known use: iroko resists many chemicals.
Shipbuilding
As a substitute for teak on decks and panelling, at a lower price.
The strongest use
Iroko as cladding
Of everything you can do with iroko, cladding is probably the use in which it makes fullest use of its properties. A façade is vertical, so water runs off; it is not walked on, so wear resistance hardly matters. What counts is dimensional stability, rot resistance and how the wood ages — and iroko scores highly on all three.
Moves little
Iroko is exceptionally stable for a tropical hardwood. On a façade ten metres wide that means gaps that are still just as wide after five years.
No treatment needed
Durability class 1 to 2 without impregnation. You can fit an iroko façade and forget it.
Greys evenly
The golden brown turns to silver grey within a year — and unlike many species it does so evenly, without patches in the places that catch more rain.
Lighter than most hardwoods
Around 650 kg/m³ compared with 1,100 for ipé. That makes a difference in the substructure and in the fitting work.
What to watch when fitting
Use stainless steel fixings: the substances in iroko react with ordinary steel and cause black streaks. Provide a ventilated cavity behind the cladding so both sides dry equally fast — a cladding board closed off on one side will warp. And seal the end grain, because that is where moisture gets in fastest.
Let it grey or keep the colour
The same story as with teak: choose one and stick with it.
For durability you don't need to do anything. If you want to keep the golden-brown colour, oil it every year with a wood oil in the right colour — see the Restol collection. Clean with lukewarm water and a soft brush; no pressure washer.
Frequently asked questions about iroko
Is iroko as good as teak?
For outdoor use it comes close: the heartwood reaches class I to II, teak class 1. The difference lies in the natural oil — teak contains more, which makes it even more stable. Iroko is, however, noticeably cheaper.
Why is iroko also called kambala?
That is simply another trade name for the same wood, depending on the country of origin and the supplier. "African teak" also crops up, although that is misleading — botanically it is not teak.
Can iroko go outdoors untreated?
Yes, provided you use heartwood. That reaches durability class I to II and needs no treatment. The sapwood does: it is in class V and does not belong in outdoor work.
Why does iroko damage my tools?
Because of hard calcium deposits that are sometimes in the wood. They are rare but hard enough to ruin a saw blade. Use carbide and watch out for sparks or sudden resistance.
Do you sell iroko?
No. Our furniture is made of pressure-treated spruce, Douglas fir, teak and other hardwood. Iroko is in our register because it is a frequently asked question for exterior joinery and decking.
Iroko in perspective
Iroko is a reference species in our register — wood we don't work with, but do know.
Have a question about your project? Just ask — we're happy to help.
Milicia excelsa — Tim van de Staak, CC BY-SA 4.0 · Milicia excelsa — Philipp Zinger, CC BY-SA 4.0 · Photo via Wikimedia Commons: Milicia excelsa — Christleo, CC BY-SA 4.0