According to EN 752-5 [DINEN752-5:1995], renovation is understood to be measures aimed at improving the current functionality of sewage pipes and sewers under full or partial inclusion of their original substance.
The measures used for carrying this out are (Image 5.3.1-2) :
Renovation processes are applied to locally limited, repeated damage (Image 5.3.1-1) as well as for extensive damage. The process always extends for at least one section of the sewer.
The cross sectional dimensions of the section of the sewer to be rehabilitated in the application of these measures are generally reduced. For this reason, checks must be made during the course of the renovation measures, whether the reduction thus caused is permissible in view of the flow capacity (Abschnitt 5.6.1).