This third edition of Bill Ransom's classic short textbook provides a solid introduction to the study of defects in buildings and, in consequence, to good practice in conservation and repair. Building failures continue to occur despite continuing experience and growing knowledge in the industry; they may even be on the increase due to cost-cutting measures, the inadequate testing of innovative products and techniques, a lack of maintenance, and user abuse and misuse. New material includes an outline of the principles of building pathology; new sections on deterioration mechanisms, service life prediction and dampness investigation. Complete with a handy glossary and bibliography, practitioners and students will find this an excellent source of guidance and information for investigating and avoiding building failures.