Acoustic methods for locating fire spread paths in old buildings

It has been well known for a long time that many fires in old buildings spread rapidly. The cause of this is often the penetration of smoke gas th rough ducts or unknown cracks or cavities in the building structure. In order to describe and analyse this problem, a number of non-destructive methods, which could be used to identify such possible smoke distribution paths in walls and floor structures, have been studied. It was found that an acoustical method showed promising results. This method was used in a couple of experiments at the Royal Palace in Stockholm and later on in laboratory experiments. The results from these experiments show that the use of standardised sound insulation measurements, together with listening tests, has the potential to locate possible fire distribution paths. Furthermore, some properties of a path, e.g. a crack length, can be deduced, a fact which can used as an additional help to locate the path. (C) 1998 Elsevier Science Ltd.