Hi everyone I am nearly at the end of me kitchen extension and fitting a new island sink however I'm hoping to get help with a question on my current kitchen drain. The kitchen drain previously exited the house into a gully trap with a rodding eye cover. The wall has now been removed and concreted over by the builder who has partially covered the gully with membrane and had the previous 40mm pipe extend out of the floor from the gulley. - my question is - do I have to dig out the concrete and remove the gulley and connect 110mm pipes to the outflow part and bring these across to the island near the mains water and then connect an Alpine 110mm bung with a 40mm offset so it’s flush with the screed and then connect my 40mm pipe to the new island sink with an admittance valve.p really concerned and welcome any comments as the plumber is saying this job should be preformed by the builderView attachment 350619
