For as long as concretes have been used as substrates there has been a need for upgrading the immediate working surface, in some instances nominally, in others substantially. This in itself has presented problems because of the inexact nature of the art and the conditions under which upgrading is required to be performed, not to mention the variety of surfaces and products. The aim of this text is to highlight the best parameters for success and to provide the reader with a comprehensive introduction to the subject. The coverage does not stray into unnecessary polymer science, but...