All buildings sealants once installed are exposed to environmental degradation factors which affect their performance over time and ultimately cause them to fail. Replacing failed sealant joints is time consuming and can be expensive, representing a substantial proportion of the overall building maintenance costs. Specifiers therefore increasingly need to know the predicted service life of a sealant in order to estimate the overall cost associated with the weatherproofing of the building. The papers, presented at the Durability of Building Sealants Symposium held under the joint auspices of the British Building Research Establishment (BRE) and of RILEM (TC139-DBS), reflect state-of-the-art research into sealant durability. Topics covered include research on the physical and chemical changes caused by the environmental degradation factors and the development of accelerated test methods which are capable of simulating the degradative environment to produce a good correlation between accelerated and natural ageing results. This book will be of particular interest to researchers at national test and qualification institutions, development and technical service personnel at sealant manufacturers, senior construction engineers and architects in consulting companies and senior construction and maintenance engineers.