Ageing infrastructure and increasing populations have resulted in the development of pipe rehabilitation as a fundamental concern in the maintenance of essential underground services. This category encompasses methods of restoring integrity to defective pipelines and underground structures and extending their operational life.

Rehabilitation is divided into three sections; renovation, replacement and repair. Renovation is a method in which all or part of the original fabric of a pipeline is incorporated and its current performance improved. Replacement is the rehabilitation of an existing pipeline system by the installation of a new system, either on or off the existing line without incorporating the original fabric. Repair entails the rectification of local damage.