Wood: building material of the future

Press, 3 September 1986, Page 13

Wood: building material of the future

For many years, wood has been almost ignored as an element in industrial construction. Of all the commercial buildings erected in Christchurch recently, none has been built entirely of wood. Yet for many centuries, wood was a main building '• component and was the . only material capable of spanning large distances. * Professor Julius Natterer, professor of timber structures at the Swiss Federal Polytechnic University in Lausanne, t believes that wood is the building material of the future. In Christchurch to talk to architects, engineers, and people in the timber industry, Professor Natterer says that the properties of wood mean it is just as suitable for construction as steel and concrete. “Regarding the relation of weight to possible load, wood is superior to most other building materials,” he maintains. While it will burn and absorb moisture from the air, these negative aspects can be eliminated with constructive and chemical protection, he believes. Solid timbers also retain their load-bearing capacity in a fire longer than most other building materials, such as steel, which buckles under intense heat and collapses. Professor Natterer explains that in a wooden building it is usually the contents that burn quickly and not the exterior. “In regard to availability and quality, wood has advantages in that it grows again. It is our only renewable material — all

other resources, including oil and metals, are not renewable.” Since the industrial revolution, iron, steel and concrete have become the predominant materials for building, says Professor Natterer. “This cannot be explained merely by the fact that these materials were simply better than wood, but that their development and use was pursued by an expanding section of industry which had a much greater capital and development potential than the manually structured timber industry. “Apart from the introduction of laminated wood at the beiginning of the century, timber structures have developed very little since the Middle Ages — development in timber structures is way behind that of other building materials.” This is one of the reasons why the Swiss Government established the professorship of timber structures, says Professor Natterer. Another reason is Switzerland’s heavy reliance

on timber as a raw material. "Switzerland has no other raw materials — everything has to be imported,” he points out. The chair at the university was established to help promote timber and give people a better realisation of timber structures. At present, the Swiss forest industry is in trouble because not enough wood is being felled, he says. “Employment in the Swiss timber industry,

which plays an important role in the economic structure, particularly of rural areas, is threatened.” “It is for these reasons, and also in view of the significance of timber in times of crisis for the autonomy of Switzerland, that there is a trend towards developing the use of timber in building.” Economic advantages have also increased interest in timber buildings in the United States and Canada, says Professor Natterer. “In central Europe, the present renewal of timber construction is mainly

based on the rediscovery of its aesthetic possibilities,” he says. Professor Natterer believes the energy required for providing and preparing timber is considerably less than that for other building materials. “With the rising cost of energy, the competitive position of wood must, therefore, improve in comparison with building materials with a greater energy input. “Wood, with good planing, execution and handicraft, is a precious materrial and not just something for people to burn,” Professor Natterer says.

In Residence

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Sarah Sands