NATURE OF WOOD

Wood has been associated with man since time immemorial. Unfortunately, many architects, builders, contractors and specifiers shy away from using wood because of their lack of understanding of the material and the common myths and fallacies associated with wood.

One fundamental aspect of wood that must be understood is that it is a biological material and therefore subject to environmental factors that influence its formation and growth. This makes wood variable i.e., with different densities and technical properties, so no two pieces of wood are similar. Once this tenet is understood, wood becomes a more accommodating material, lending itself to a huge variety of uses and applications, largely due to its ability to fulfill both form-and-function requirements.

Technical research on Malaysia’s timber species done by the Forest Research Institute Malaysia has contributed significantly to how different timber species can be treated, cured, dried and utilized.

This section:

1. Addresses the common concerns that surround the proper usage of wood by explaining why wood behaves as it does.
2. Lists the green credentials of wood and its inherent advantages over other building materials.
3. Explains how specifying timber, particularly from certified and/or legal sources, actually contributes to forest conservation and climate change mitigation.

Our aim is not to promote the exclusive use of wood. There is a place for all materials in enriching our built environment. This is a case for using more timber, particularly from legal and sustainable sources. Through this better understanding of the properties and proper usage of timber, more timber will be specified for construction projects.

The Nature of Wood

Wood is a Biological Material

Wood is made up of cells, which tend to be elongated and are arranged along the longitudinal axis of the tree trunk. These cells are made up of a complicated mixture of polymers of cellulose, interspersed with other noncellulosic
carbohydrates and lignin. These cells act as tiny elongated thin-walled tubes and impart some outstanding physical and mechanical properties to the wood.

Wood is Anisotropic

Wood behaves differently along its three major differential axes in terms of strength properties and dimensional movements.

Wood is Hygroscopic

Wood is subject to changes in moisture content of its surroundings. The temperature and humidity of the surrounding atmosphere and the amount of water already in the wood will determine whether wood absorbs or loss water vapour. These absorptions or loses of water vapour will cause the wood to swell or shrink. The anisotropic nature of wood will cause unequal dimensional movements in the three directions.

Wood is Inert

Wood is inert to the action of most chemicals. This property makes wood suited for many industrial applications where resistance to corrosion is important. When wood is exposed to atmospheric conditions, it will only erode at a rate of 0.25 inch per century. Even this can easily be prevented by applying coatings and proper treatment on the wood surface.

Advances in R&D by many research agencies globally have contributed to a rich and growing repository of knowledge on timbers, resulting in the development of various treatments and techniques as well as recovery and engineering solutions to manage timber’s natural properties to enhance its usage, enabling timber to be used more intelligently with a lot less wastage.