ABSTRACT
Aside from producing unsightly efflorescence on the surface of the material, the crystallization of some salts can cause extensive delamination of porous materials. The salts may originate from within the material itself, for example the sulphates contained in bricks; from a direct or bridging contact with the ground; or as pollutants in the surrounding atmosphere, for example road salt. Chlorides and sulphates produce particular problems which are discussed elsewhere in this book.
