Fitted new waste outlet to bathroom sink, (the sink has an internal overflow) the inside sink piece has rubber seal (and I've put a bit of extra sealant). Below sink piece has a rubber washer (one side flat and one side domed) and a large nut.
Doesn't seem to make a difference which way below sink washer is put on, seal is watertight. However, water is running down the thread (definitely - I can actually see it).
Have tried white 'plumbers tape' wrapped around the thread but makes no difference, water still forcing it's way out from there.
DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!