The flatowner above mine (Mr. X) had changed his entire flooring 10 years back ( at the time of possession ). Soon my flat started facing seepage issues. Mr. X would apply white cement in gaps and that would serve as a stop gap solution. After few months seepage would start again. He would again take some stop gap measures and sort it for time being. Now he has moved out and given flat on rent. The seepage issues have started again. The seepage is causing small cracks in my ceiling and also the paint, plaster etc gets spoiled. Plumber told that it could cause a ceiling collapse if not solved permanently by doing proper water proofing. Proper water proofing would cost around 1-1.5 lakhs. Society bye- laws state that the cost has to be shared by both flats. However, Since Mr. X had done his flooring himself, how am I responsible for bad quality of work? Can i force him to sort out the issue at his cost.