Continuous rc Slabs - Reconciling Theory with Practice

Lateral restraint for cold-formed purlins A number of our readers have written to us seeking, or providing, advice on the effectiveness of lateral restraint for purlins in lightweight steel roofing systems, since Mr L. Wadsworth first raised the problems of design in April 1983. Further information is now provided by Dr. S. J. Bates who writes on behalf of his firm as follows: As the largest UK manufacturer of cold-formed purlins, selling systems which have been independently designed and tested at the country’s foremost universities, specialising in the design of cold-formed sections, we have always taken a pride in our ability to offer a technical backup service to deal with specific inquiries. Perhaps the time has now come to offer a general discussion on points raised in open forum, although we would emphasise that specific questions should always be dealt with on an individual basis and we are always willing to discuss particular applications with individual engineers. Verulam

Mr M. Shears (Ove Arup & Partners): The author is to be congratulated on giving us such a comprehensive description of this interesting and unusual structure.

Mr G. M. Pinfold (F) (NCL Consulting Engineers): First, I should like to say how interesting the paper was, particularly in the treatment of structural arrangements not normally considered as being wind-sensitive.