Why line or patch line a drain?

If we find serious fractures, cracks and/or roots in a drain using our CCTV camera equipment the only two options would be to excavate or to line the drain. Lining and patch lining repairs the structural integrity of the drain without the need to dig.

How is it done?

Drain Lining

Firstly the drain is cleaned and/or root cut using our high pressure water jetters and root cutting equipment (see root cutting page). We will check the drain is ready using our CCTV camera’s.

A structural liner is impregnated with a mix of chemicals. We can choose either a polyester or a silicate resin mix depending upon the circumstances. We use a set of rollers to impregnate the liner. The liner is then inserted inside the drain. This can be done by inverting the liner using air pressure or by dragging the liner in place. Once the liner is in place and the ends are cut as required we will inflate the liner to the shape of the drain using and inflatable calibration hose. The calibration hose can be inflated with either air or water. The calibration hose remains inflated until the chemicals cure in the liner. The chemicals are ambient temperature cured for small diameter pipe liners. Once cured we remove the calibration hose and check the repaired drain using our CCTV camera’s.

Drain Patch Lining

We would clean and root cut the drain using our high pressure water jetters and root cutters (see root cutting page). The drain would be checked using our CCTV camera’s on cleaning to ensure the drain is ready for installing our patch liner.

We cut the correct size of fibre glass matting which is our patch liner material. We connect our inflatable packer to a set of air rods and mark the position of the repair onto them. We mix our silicate resin chemicals and impregnate the fibre glass matting. The patch liner is folded and wrapped around the inflatable packer before being inserted to the correct position in the pipe. We use the CCTV to check the position and also check the patch liner has not creased or moved in transit. The patch is then inflated using air pressure to mould the patch to the inside of the pipe. The inflator is left in place until the patch liner has cured. The chemicals cure with ambient temperature.

How long will the repair last?

Our lining material exceeds WRc criteria and provides a 50-year design life with a safety factor of 2, effectively giving one hundred years life expectancy. We use the most up to date sewer renovation methods and materials which adhere to WRc criteria to ensure all works are carried out to Water Authority Standards.