IN BUILDINGS AND CIVIL ENGINEERING STRUCTURES, water should generally be kept out and away to prevent deterioration and damage, with subsequent loss of value and/or function. In addition to the problems of water penetration and damp, water ingress can also bring many other deleterious soluble materials into the substrates, including salts such as chlorides and sulphates, plus other aggressive influences. There are therefore several different reasons for using a hydrophobic impregnation