I bought a property a while back and it has a small toilet room with a sink. Of and on it has had sewer gas smell which I recently traced to the waste of the small sink.
Lots of problems with the sink, like it was not installed level so that none of the plumbing fits properly.
Anyway, I also noticed that the waste is an embedded plastic push fit elbow, the small part of the elbow sticking out of the wall. Inside the elbow joint is a single rubber ring seal.
Is this normal? What is the best way to make this truely water tight and air tight?
I don't want to have to dig into the wall and start a major building operation.