F. PEAKE, W.A. DUROSE and G.J. EDGELL CERAM Building Technology

A number of test walls have been constructed using two types of facing brick with 75mm cavities formed by an inner leaf of lightweight concrete blocks. The cavities were filled with blown-in rock wool fibre. In some cases the outer leaves were deliberately built with poorly filled perpends so that the effects of high leakage rates through the outer leaf on the resistance to rain penetration of fully filled cavities of this width could be studied. The effects of wrongly sloping wall ties have also been examined, with and without mortar contamination. The tests were all carried out using BS methods and apparatus. The test regime for all tests was based upon the British Board of Agreement (BBA) test for fully filled cavity insulating materials. Penetration of the inner leaf was observed in some cases and so the effectiveness of remedial work was also assessed.