INTRODUCTION

Timber is a product of wood from felled trees suitable for construction purposes. Timber is one of the oldest and natural civil engineering construction materials. Three terms pertinent to timber one of interest. They are:

1. Converted timber – This is the timber that is sawn and cut into required sizes for commercial use.
2. Rough timber – This is the timber that is obtained after felling a tree.
3. Standing timber – This is the timber that is in a living stage.

Wood, as a building material, has a number of valuable properties, viz., relatively high strength, low bulk density, low heat conductivity and amenability to mechanical working.

Despite its remarkable uses, wood has several shortcomings, viz., different strengths because of anisotropy, susceptibility to decay and inflammability.

Properties of timber and timber-based products as a building material are discussed in the subsequent sections.

10.2 TREES

10.2.1 Basic Structure of a Tree

A tree consists of a trunk, a crown and roots. The functions of the roots are to implant the tree in the soil, absorb moisture and mineral substances it contains and in turn supply them to the trunk. The trunk supports the crown and serves to provide water and nutrients from the roots to the leaves through branches and from the leaves back to the roots.

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