According to EN 752-5 [DINEN752-5:1997], repair is understood to be measures to rectify local damages.
These repair processes (Image 5.2.1-1) include:
- Restoration (Abschnitt 5.2.1) ;
- Injection processes (Abschnitt 5.2.2) ;
- Sealing processes (Abschnitt 5.2.3).
Repairs from outside are carried out to manhole structures as well as to the sewer itself. They require, among others the digging of an excavation.
Repairs from inside of man-accessible sewers and structures are carried out by machine or by hand and/or with the use of suitable aids or apparatus and in non-man-accessible sewers with the aid of remote controlled robots. They can also be utilised as help or preparatory measures for renovation processes (Abschnitt 5.3).