A maintenance company in Canterbury were getting re occurring blocked drains in some flats they maintain. We were called in after the fourth blockage in two months. A drain cctv survey was carried out and we quickly identified mass root damage on a couple of joints in the pipe work. The drain was jetted clean, before a mechanical root cutting machine was used to cut the roots away leaving the pipe work full bore and ready for the repairs to take place. The drain run was 22 metres long, so a full length liner would have been very costly. The most cost effective means of repair was local structural repairs. A part line or sometimes known as a patch, is inserted into the drain and pushed down to the point where the root had breached the pipe. Once in the correct position the patch kit is blown up to 2 bar of pressure and left to cure. Once cured the repair system is removed from the drain leaving the part liner in the drain sealing it from any chance of the roots coming back at that point. This drain relining means of repair is very helpful as it is minimum disruption to the homeowners and with no large excavation needed it really keeps the cost down. The company have not had any problems with the drain since the work was completed.