Roofs fail for a number of different reasons, and the consequent costs are high--not only for clients but for contractors and other professionals. Carl Cash draws on a long career in the roofing industry, having analyzed 1500 different cases of roof failure. He discusses the source of the problem, the steps needed to prevent recurrence, and the principal remediation alternatives.The book starts by setting out the duties of a building pathologist in the context of the modern roofing industry, defining failure and explaining its underlying causes. The main chapters then deal with the main specific types of failure: fire, shrinkage and roofing systems displacement, calendar shrinkage, foam insulation shrinkage and 'stretched' membranes, plasticizer migration, bitumen incompatibility, built-up roofing felt porosity, blistering, thermal insulation instability, foam insulation problems, torch applications, polymer dispersion, asphalt-glass fibre shingle splitting, lack of appropriate venting, problems with cool roofing and problems with organic fibre-portland cement shingles. The book concludes with an outline of the principal rules for long service life roofing.