This Technical Report gives guidelines for the selection of a proper grout material to repair water leakage through cracks and other discontinuities in concrete structures including the following:? conditions of water-leakage cracks;? performance requirements for repair materials;? different types of repair materials (grouts);? procedures followed to select the appropriate repair materials;? execution of different types of repair methods;? performance assessments of applied materials and methods;? data collection.This Technical Report does not include a focused section about the repair of dry cracks and the causes or the origins of cracks. The details on dry crack repairs are covered in ISO 16311-41).A flow chart for maintenance of water-leakage cracks is shown in Figure 1.