The connection areas of connecting laterals must be permanently tight and free of backflow. The condition of the connection area must be taken into account when selecting the reconnection technique.

The stresses that occur in the material during the hardening of the lining tube are caused by thermal influences and volume changes (shrinkage, especially with UP-NF). These can also lead to length changes. Therefore, the reconnection may only be made after the stresses in the CIPP liner have subsided.