Materials Considerations Regarding Rain Penetration In Historic Fired Clay Brick Masonry

Moisture is a major source of damage in historic massive masonry. Therefore control of moisture movement in masonry is instrumental to the durability of masonry buildings. From research and practical experience it is known that a series of causes may play a role regarding permeability problems in masonry. This paper is focused on materials aspects regarding water penetration in historic fired clay masonry walls, constructed with moderate-to-high absorption bricks and lime mortars; the occurrence and influence of parameters such as brick porosity, interface leakage and mortar joint resistance are discussed. Subsequently, quantitative tests results are given on the effects of these parameters on the leakage of massive walls of different thicknesses. The results of the investigations lead to a number of recommendations to be used in case of repair of historic massive masonry. Finally, attention is paid to the influence of workmanship on the permeability behaviour of historic massive walls.