Iroko

General Description

West African Iroko is imported at grade FAS, mainly kiln dried. It is yellow when freshly machined which quickly changes to medium, then darker brown). When used for exterior joinery such as garden furniture it will become silver-grey if left untreated. Iroko is commonly used as an inexpensive alternative to Teak (they are very similar in density, grain structure and colour after ageing), due to Teak's scarce nature and strict export laws. When machined, despite careful pre-straightening, some products may twist and bow shortly after processing. Part of this issue is down to the denseness of the timber and part of it is down to have interlocked grain. Interlocked grain spirals around the centre of the tree thus alternating intermittently and causing a 'rough' effect, this can generally be reduced if not eliminated by heavy sanding.

Thicknesses: 25mm, 32mm, 38mm, 50mm, 63mm, 75mm & 100mm. Widths mainly 130mm - 350mm, average about 200mm. Lengths; generally 2m - 4.8m.

Working Properties

  • Works fairly easily with hand or machine tools (some tearing of interlocked grain)
  • Occasional deposits of calcium carbonate severely damage cutting edges
  • Good nailing and gluing characteristics
  • Moderate steam-bending properties
  • May cause dermatitis in working wet wood
  • Dries rapidly with minimum degrade
  • Little movement in performance

Physical Properties

  • Medium hardness, weight, bending and crushing strength
  • Very low stiffness and shock resistance
  • Moderate steam bending
  • Good stability

Durability

  • The heartwood is very durable
  • The heartwood is reported to be naturally resistant to decay
  • Heartwood is susceptible to attack by dry-wood insects
  • Sapwood is susceptible to attack by powder-post beetle
  • Sapwood has been reported to be highly resistant to termite attack in Africa

Main Uses

  • Suggested as a teak substitute
  • Joinery
  • Boatbuilding
  • Piling and marine work
  • Domestic flooring
  • Furniture
  • Cabinetwork