Design of Steel Cables Against Free-Bending Fatigue at Terminations

Preservation of structural timbers Correspondence on this topic has appeared several times in Verulam since it was first raised by Mr P. A. Campbell of the State of Victoria, Australia, on 20 August 1991. On 15 September we had the benefit of a letter from Dr A. F. Bravery, Head of Timber Division at BRE, responding to the points raised, in particular to Mr Campbell's criticism of the reliance placed by BS 5268 on a 'process’ as opposed to a ‘results’ procedure. Mr Campbell has again written questioning the reliability of the provisions of BS 5268: Part 5 and BS 5589 in ensuring what he considers to be the necessary degree of quality control in preservation procedures for structural timber. He complains that he has found it impossible, despite continuing efsorts on his part, to obtain evidence of published data to support the adequacy of the procedures specified in those standards: My comments refer to timber exposed to BS 5589 hazard categories 4 and M. Verulam

The Building Regulations for England and Wales, including the span tables for site-cut timber roofs for dwellings, have recently been revised and reissued. This paper demonstrates that the information given in, and with, the span tables is insufficient to form a safe roof of this type and goes on to propose alternative structural configurations. Finally, the paper argues that the span tables should be removed from the Building Regulations and that design of all timber roofs should be entrusted to structural engineers. J.B. Bellamy