How to repair a damaged drain.Defects with drains can be found with a CCTV camera during a drain survey. How to repair a damaged drain.Defects with drains can be found with a CCTV camera during a drain survey.We put a wrap around the packer, so the patch doesn’t stick to it once cured. The purple bit is the calibration hose, to stop the packer expanding out of the drain and potentially deforming the packer. A patch with resin is put over the packer and held in place with elastic bands to hold in