Microbial activity can have an important impact on the durability of building materials. It is important to understand this activity in order to select appropriate treatment strategies for the repair and restoration of buildings and monuments. This paper describes the microorganisms which can modify the properties of building materials such as concrete, mortars, composites, timber, gypsum, etc., as well as the mechanisms responsible for deterioration of these materials. The information provided by the members of TC 183-MIB via a questionnaire is discussed. Techniques currently utilised and areas requiring further study are identified. In addition to the references, a list of publications for further reading completes this article.

This paper presents various techniques for materials characterisation in relation with the question of microbial impact. Applications examples of some of these techniques are described as well as the respective results obtained by researchers working in this field. Additional readings are also reported.1359-5997 © 2005 RILEM. All rights reserved. RÉSUMÉ Cet article présente diverses techniques de caractérisation des matériaux vues sous l'angle de l'étude des impacts microbiens. Des exemples d'application de certaines d'entre elles sont décrits ainsi que les résultats obtenus par des chercheurs travaillant dans ce domaine. Une bibliographie complémentaire est également fournie.