Disfigurement of any concrete surface is at least a source of annoyance, and this publication attempts to mitigate the problem in its chemical and physical aspects. It deals with the broad scope of elemental attack by the vagaries of weather and by salts as they move to the face of a building to result in discoloration and, at times, disruption. Much research has in particular been devoted to the cause and nature of efflorescence, an expressive yet ambiguous word which suggests flowering and fruition but describes an effect that almost vies with vandalism. While elusive, however, it is not an intractable phenomenon and can be cured in more senses than one. Its stalactites or bloom can be alleviated by common sense and scientific forethought, given all the rules of quality control. This largely aesthetic problem is conditioned by factors such as temperature, absorption and lack of imagination, with cement and aggregates of lesser importance. The text covers staining of many kinds, superficial but unsightly, and due to faulty workmanship or detailing. Concrete is too readily assumed to have strength and durability only, with an acceptable countenance underestimated or ignored. This work should help towards an appreciation of its potential in visual as well as structural terms.