Cured-in-place pipe (CIPP)

Cured-in-place pipe, commonly abbreviated to CIPP, is a trenchless rehabilitation technique in which a flexible liner impregnated with thermosetting resin is inserted into a damaged drain and then cured to form a hard, jointless new pipe within the host. The liner can be installed by inversion or pulled into place, and curing is achieved with ambient temperature, hot water, steam or ultraviolet light depending on the resin system. CIPP is widely used on London Victorian clay drains affected by root ingress, cracked joints or surface scaling, where excavation would damage paving or party walls. The technique should be carried out in accordance with BS EN ISO 11296 and verified by a post-installation CCTV survey before being put back into service.