Iroko

Technological properties

The drying time is normal. It dries well and there is no risk that deformations will arise or that cracks will occur. In open air drying, battens show more or less pronounced markings. This flaw can be avoided by drying vertically before stacking or exposing the wood to the sun for a few weeks so that the colour is uniform after drying. It is similar to teak, but its texture is coarser, it is lighter, and it does not have its characteristic scent and oily feel.

There are sometimes stone deposits in cavities. Despite not being too strong, iroko wood can be compared with teak due to its other properties. It is also very durable and provided that the direction of the grain is continuous, it slightly outperforms it in stability. It can be sawn and worked on easily, although the stone deposits may damage the teeth of saws and the blades of cutting tools. It may have mineral deposits which give a brown appearance, causing problems in sawing.

When dry wood is sawn, the fine sawdust may cause allergic reactions. It is good for obtaining rolled and sliced veneer with a high performance in the latter case as a result of the average diameter of pieces, with only the stone deposits causing problems. When the fibre is intertwined, it can create customised veneers, with great applications for decoration and furniture. There is no problem gluing, nailing or screwing. It is repellent to paint, varnishes and stains which dry by oxidation. This is a result of the presence of chlorophyll (an antioxidant) which prevents the drying of stains. This problem can be resolved by cleaning with alcohol or ketones, it not being advised to clean with turpentine. It is recommended to first use a primer.

Origin and availability

Also called fake teak or African teak.

It is an important African wood, used throughout its wide area of distribution in Tropical Africa, from Sierra Leone in the west to Tanzania in the east, and from Senegal to Ghana.

It is a very large tree, 50m tall, which produces smooth cylindrical trunks which, in Africa, are usually exported after being cut into quadrangular sections, or having no sapwood.

There forest masses are large with stable production, commercialisation and export. The export of round iroko wood is prohibited in Côte d’Ivoire and in Ghana.

Description of the wood

Iroko has a colour which varies between yellowish brown and dark brown, but its appearance is very characteristic due to the pale bands of soft tissue associated with glasses. The colour of the sapwood is pale yellow or yellowish white, and the heartwood is yellowish brown, which turns golden brown when exposed to light. When it is exposed outdoors, the wood takes on a greyish white colour. The growth rings are visible and their wood rays are fine.

Natural durability

The wood is classified as durable or very durable against fungi, durable against termites and sensitive to marine xylophaga. The sapwood is sensitive to powderpost beetles.

The heartwood is not penetrable, but the sapwood is.

Applications and use

Iroko wood has a combination of very favourable properties. It is suitable for the same applications as teak, although it lacks its decorative effect, and is therefore seldom used for the manufacture of furniture. It can be used in the construction of boats and other vessels, and on domestic and public countertops and benches. Other uses: Decorative veneers, structural plywood boards, doors, windows, floors, parquets, staircases, carpentry, construction carpentry, glued laminated wood, bridges, turnery, etc.