Wood

Wood is a porous and fibrous structural tissue found in the stems and roots of trees, and other woody plants.

It has been used for thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers (which are strong in tension) embedded in a matrix oflignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees,^[1] or it is defined more broadly to include the same type of tissue elsewhere such as in the roots of trees or shrubs. In a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, or wood chips or fiber.

The Earth contains about 434 billion cubic meters of growing stock forest, 47% of which is commercial. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991, approximately 3.5 cubic kilometers of wood were harvested. Dominant uses were for furniture and building construction.

Different types of wood

 Akasa
 A straight-grained grey-brown heartwood and sapwood. Its uses include interior joinery, light structural work, flooring, utility furniture, veneer for plywood and turnery. A general utility interior wood.

Ash 
A light wood with a distinctive lustre when polished. It has an open grain and is reasonably hard wearing. Ash can be successfully stained to almost any colour.

 Balsa
Although it's one of the softest and lightest weight timbers, balsa is a hardwood. It's used for heat, sound and vibration insulation and for model making.

Bamboo
Bamboo has a rich golden colour that's very hard wearing. It's impervious to moisture, so is often used in conjunction with the ornamental part of a water feature or for flooring in bathrooms, conservatories and other wet areas. Chapter 44 of the Tariff covers the trunk part only and not the foliage. 

Beech
A hard durable wood that in its natural form comes in a variety of warm, soft honey tones. Steamed beech has been treated at high temperatures to create a unique red colouring.

 Brazilian mahogany 
Denser than many African mahoganies. It's very durable and can be used as boat building timber and for constructional work.

British pine
See Redwood, European.

Cedar
Western red cedar is a lightweight softwood used for construction work. It's durable with a straight grain.
 Celtis
A straight-grained but sometimes interlocked wood. It has yellowish grey heartwood and sapwood and a fine texture with a slightly lustrous look. Its uses include interior joinery and trim, flooring, mouldings, veneer, plywood, handles and some furniture.