Timber is a common building material. It is
convenient to use and is a renewable resource. It is
strong, versatile and often offers the best economic
option for the construction of a variety of buildings.
The benefits of building with wood are greatly
limited, however, if the timber is vulnerable.
As an organic material, unprotected wood is affected
by climatic, biological, and human factors. These
weathering (e.g. rain, blown sand or grit)
moisture (e.g. condensation)
heat (e.g. solar radiation)
insects (e.g. termites, beetles, wood wasps)
fungi (e.g. moulds, stains, rots)
In recent years, many people have recommended
chemical preservative treatments for timber
Figure 1: Building with timber
protection. There is no doubt that these methods are
effective, but a number of health hazards and environmental problems have been found to
In some cases (such as in situations with a high risk of fire or fungal and insect attack) chemical
treatment may be unavoidable, but if other protective measures are employed as well, the
preservatives used can be of low toxicity and
therefore less harmful. In many instances (such as in situations with a low risk of fire or fungal
and insect attack) non-poisonous timber protection practices can be employed to avoid any
chemical treatment of wood.
This Technical Brief outlines:
the disadvantages of treating timber chemically; and
means of protecting timber, including examples of protecting timber by proper felling
and seasoning; by good design and construction practices; and through the use of
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