The safety of historic structures

I have worked on many projects involving historic structures. Drawing upon my experiences and understanding gained, this paper endeavours to put my comprehension of conservation into context, looking at the pivotal role we, as structural engineers, can play. Principles of ‘minimum intervention’, ‘sympathetic approach’, ‘reversibility of repairs’, ‘maximum retention of historic fabric’ all require our consideration. A variety of projects are used by way of example, ultimately showing that compromise almost invariably ends up being the only way to succeed. Andrew J. Hallum, BSc(Hons), CEng, MIStructE, MICE Associate, Capita Symonds

A simple and practical method of monitoring buildings for foundation movements is proposed that provides data on actual vertical movements to an accuracy of 0.1mm or better. The technique uses laser-cut plastic movement gauges that can be read with a basic optical level from close range. Installation and reading costs are similar to crack monitoring but case studies with historic buildings and insurance claims illustrate the potential for results to be useful within just a few weeks. Robert Thorniley-Walker, MA(Oxon), CEng, FICE, FIStructE, MIHT, IHBC Director of Structural & Civil Consultants Ltd