Repair to Drainage Pipe

[sleevey]

Hi

I need to repair a drainage pipe from my flat that is leaking into the flat below. I have accessed the pipework by removing a segment of the plasterboard ceiling. I can see it was repaired once before but has started to leak again. it is a 3' grey drainage pipe that runs out through to a hopper on the outside of the building. Isthere anything i can use on the pipe to reseal it without having to cut the pipe or will i have to crack the concrete on the os wall so I can get a collar on it to repair the section that is leaking.

At the moment you would not be able to move the pipe once you have cut it so i guess i will need to get access to the os hopper? I also need to confirm if there are anymore tee's/branches in the pipework before i start this work. any advice would be appreciated.

Thanks

please see attached photos[img][/img]