If you are having recurrent drainage problems, your local drainage company in London might suggest that you have a CCTV survey to see if there is any structural damage to the pipe network.
CCTV surveys are an important tool and can be used to assess damage within a section of pipe. When a drainage company knows what is wrong, they can suggest a suitable repair.
If during a CCTV survey a section of pipe is found to be cracked or if there is a gap between sections of pipe, the drainage company may suggest a liner repair. To install an epoxy flexi line, the drainage company simply has to blow the liner into position to the corresponding section of damaged pipe. Once the liner is in position the drainage company inflate it and the impregnated resin liner sets, bonding it to the pipe wall. This covers any fractures in the pipe and stops water getting through the pipe and causing a damaging void.
When the liner is in place, the cross section of the pipe will be slightly reduced but the pipe will be repaired so the flow rate will be increased by as much as 15%.