R. C. DE VEKEY, K. TARR and M. WORTHY Building Research Establishment.

Wall ties play a key part in ensuring the structural integrity of a wide range of masonry and masonry-clad buildings. Ineffectual bonding due to the wrong type of tie, insufficiently long ties or workmanship faults such as the widening of cavities beyond specification is a frequent problem. This has often resulted in very expensive remedial work and, in rare cases, collapses. Wider cavities to accommodate insulation have increased the risk of insufficiently long ties being specified or used. The paper reviews the workmanship factors causing reduction in lie performance and presents recent experimental results on the effect of embedment depth for BS1243 ties.