*Building Research Establishment **Autoclaved Aerated Concrete Products Association

There is considerable interest in the concept of a cavity party wall (separating wall) for domestic housing built with loadbearing masonry without wall ties to connect the two leaves. Such a wall would give better sound resistance than equivalent tied structures because of the omission of the ties which transmit sound vibrations between the leaves; however, it would not comply with the current structural stability requirements of the Building Regulations. This paper describes some tests of individual hangers bearing on vertically spanning, simply supported 100mm thick autodaved aerated concrete (AAC) blockwork walls designed to give some insight into their likely performance in a planned full scale test. Broad conclusions are that the load is eccentric as would be expected but that the overall behaviour was surprisingly good giving a Factor of Safety of around 10 for the ratio of average ultimate failure toad/calculated live (serviceability) load based on 1.5kN/m2. Data is given on other factors including type of hanger, type of mortar, end gaps and position of hanger in relation to mortar joints.