What is azobé wood?
The Wood Guide · The wood register
Tropical hardwood · referenceAzobé
Bongossi, ekki, aba: one timber with four names, and the same reputation everywhere. If a structure has to stand in water for decades, this is the answer.
- Lophira alata
- 940–1,100 kg/m³
- Class 1, even in water
AzobéLophira alata
Azobé
Bongossi, ekki, aba: one timber with four names, and the same reputation everywhere. If a structure has to stand in water for decades, this is the answer.
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Azobé in brief
A tropical hardwood from West Africa, and the timber that Dutch and Belgian hydraulic engineering relies on.
The figures say it all: 940–1,100 kg/m³ at 12% moisture content, and freshly sawn as much as 1,100–1,300 kg/m³. That is heavier than water, heavier than most tropical species, and heavy enough that two people can barely lift a beam.
That mass is exactly why it is used in sheet piling, lock gates and bridge decks. Azobé does not give way, does not rot, and is not pushed out of shape by alternating wet and dry conditions.
Aba in Nigeria, bongossi in Cameroon and Germany, ekki in Nigeria and Great Britain, hendui in Liberia and Sierra Leone. That spread of names tells you something: the timber is valued and traded everywhere it grows.
- Botanical
- Lophira alata
- Origin
- West Africa
- Density
- 940–1,100 kg/m³ at 12% moisture
- Freshly sawn
- 1,100–1,300 kg/m³
- Durability
- class 1
- Colour
- dark purplish brown to reddish brown
To be fair: azobé splits easily at the end grain and moves a lot while drying. End grain has to be sealed, and the timber does not belong in applications where tight dimensional stability matters. On top of that: working it is hard going, pre-drilling is essential, and the dust is an irritant.
Why hydraulic engineering chooses it
Extremely dense
940–1,100 kg/m³. Water barely penetrates, and without water there is no fungal decay.
Very hard-wearing
An azobé bridge deck withstands years of heavy traffic without wearing down.
Durability class 1
Even in permanent contact with water and soil, where almost every other species gives up.
High bending strength
Long spans without deflection — the reason it is used in bridges.
What azobé is used for
| Use | Why azobé | Alternative |
|---|---|---|
| Sheet piling and bank revetments | Class 1 in permanent ground and water contact | Bilinga, or steel |
| Lock gates and fender structures | Mass and wear resistance | Bilinga |
| Bridge decks | Bending strength and wear resistance | Ipé, steel–timber combinations |
| Harbour works and jetties | Resistant to salt water | Bilinga |
| Railway sleepers | Load-bearing capacity and service life | Concrete |
| Garden furniture | Unsuitable — too heavy and too coarse | Teak, acacia, pressure-treated spruce |
Azobé is a civil engineering timber. It is too heavy to move, too coarse for furniture making and it splits at the end grain. For garden furniture, look at teak or acacia; for decking, at ipé.
Frequently asked questions about azobé
How heavy is azobé exactly?
940–1,100 kg/m³ at 12% moisture content, and freshly sawn 1,100–1,300 kg/m³. For comparison: spruce is around 450 kg/m³.
Can azobé be used in salt water?
Yes, that is one of its strongest properties. It has been used for decades in harbour works, lock gates and fender structures. See also bilinga, which can do the same.
Why does azobé split at the ends?
Because of its high density and the strong movement while drying: the end grain dries faster than the core and then splits open. Sealing it with an end-grain coating limits this.
Is azobé suitable for decking?
It can be, but it is not the obvious choice: too heavy, coarse in texture and difficult to work. Ipé is the better tropical option for decking.
Azobé in perspective
The heavyweight extreme of the register — with balsa at the other end.
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Lophira alata — Tim van de Staak, CC BY-SA 4.0 · Lophira alata — Roland Godefroy, CC BY-SA 3.0 · Deauville, Normandië — Crochet.david, CC BY-SA 3.0 · Photo via Wikimedia Commons: Lophira alata — Ajit Ampalakkad, CC0