TIMBER RESEARCH

New Zealand Herald, Volume LXXII, Issue 22172, 27 July 1935, Page 5 (Supplement)

TIMBER RESEARCH

ADVANCES IN AMERICA Mr I. H. Boas, chief of the division of forest products of the Council for Scientific and Industrial ltesearch, recently visited the United States forest products laboratory at Madison. He states that tho idea that timber is a vanishing commodity and that further study of it is unnecessary has few supporters in the United States of America, tho greatest timber-consum-ing country in tho world, Becently the United States forest products stalf has been accommodated in a new laboratory which cost £250,000 to build. Building extensions to house further projects are being made, and proposals for the spending of an additional £1,000,000 on equipmont are under consideration. Tho Madison laboratory has been carrying out timber tests of all descriptions for many years, with the result that it has built up an enormous fund of knowledge about timbers in general, and American timbers in particular. It is not surprising to find, therefore, that it is turning its attention moro and more to advanced problems in forest products. llecently a timber house of totally new design, involving a, large amount of prefabrieation, hut enabling thr> more economical and effective use of timber, was completed. Features of tho house aro the unit construction of tho walls with plywood sheathing and a special ceiling and floor construction in which plywood is glued to tho top and bottom of the joists. 13y this means tho plywood takes a large portion of tho stresses in the units when thej' are under load, and the resultant structure is light but strong and stiff. Further points of interest in the new sections ot the laboratories aro the built-up timber arches designed to give a ceiling uninterrupted by the usual roof trusses. Two types of built-up arch ribs have been used, one being of structural timber joined with timber connectors, and the other of glued laminated construction. Tho sheathing of tho roof is of plywood, glued to the purlins, so that instead of being a useless. dead load it contributes to the strength and stiffness of tho structure as a whole. These new departures' in timber construction, together with tho increasing use of timber connectors in built-up columns and large arched timber bridge construction and tho use of composite wood and concrete bridges seem to herald a now era in timber utilisation. Timber markets have suffered of recent years from tho inroads of substitutes and this has largely been due to tho fact that tho timber industry has been content to rely on tho commonlyknown features of timber, such as availability, easo of working and adaptability. Timber has many other valuable properties, and in the future these will bo exploited to the utmost in new types of construction.