Iroko

Category: 1-2

Wood density at 12% moisture content (kg): 650

Also known as:

Botanical name: Chlorophora Excelsa Benth. a Hook. Chlorophora Regia A. Chev.

Origin: West Africa, Central Africa

Use: Iroko has been competing with teak for a long time, which it can in many cases replace. It can also replace oak. It is an excellent construction wood for outdoor use where stability is demanded. Without impregnation, it lasts longer than our pine impregnated with creosote oil. Iroko is not as commonly used in Europe as would be expected due to its excellent properties. In Africa, it is important in the tropics for all construction purposes for its high durability.

Used for:

  • Shipbuilding (ship hulls and deck floors), lock gates, bridges, bridge floors
  • Construction of wagons (especially floors of freight wagons), sleepers, telegraph poles
  • Outdoor constructions, wood facade cladding and wood siding, house gates, windows and doors, frames, stairs, floors and parquets
  • Barrels, vats and tanks for chemical and food industries, in butter dairies (Iroko has proven itself to be better than oak), in laundries and dyehouses
  • On church pews, workshop and laboratory tables
  • Car bodies and paving blocks
  • Indoor equipment for massive and heavy office furniture, wood carvings

Durability: Trunks and lumber discarded od sapwood are easy to conserve/store. Heartwood is very durable and due to oily resins is highly resistant to water, mold, rot and insects. Iroko can also withstand termites and, according to some data, the naval shipworm. It does not even decay when stored on the ground. It cannot be impregnated. Sometimes, especially in the wood of older trees near the medulla, there are very hard, stony, yellowish deposits called “iroko stones”, which destroy tools during machining and can even break the saw blade. They come in various sizes and shapes and can weigh up to 3 kg. Usually, they appear as whitish or white-yellow piles of sediments composed of calcium carbonate and organic substances with a small proportion of silicon, iron oxide and aluminum.

Wood description: Sapwood: white-yellow color, sapwood is 5-10 cm thick, recognizable from heartwood, unusable. Heartwood: color of freshly cut wood is ocher yellow, turns brown quickly in the air to tobacco brown of old oak or olive brown. Texture: homogeneous, rather coarse, vessel lines are wide and clearly visible, it has rather distinct spiral grains, which cause a more or less streaked drawing on the radial and figural drawing on the tangential section, medullary rays are very fine and barely visible.

Wood treatment:

Cutting: relatively good, but requires more cutting force due to the hardness/strength of the wood, the tools become dull, fossilized deposits destroy saws and tools, so it is best to use tools with a stellite or carbide discs
Drying: average
Workability: the planing and turning angle must be adjusted due to the irregular course of grains.
Bending: mild bonding/gluing: good, synthetic phenolic resins/adhesives have proven to be effective
Nailing/hammering: nails and screws penetrate the wood well, no cracks and hold firmly
Clean workability, finishing: coating based on vinyl or formophenol or latex. Easy to stain and after previous use of a good grain filler is easy to polish and shines beautifully.