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Discuss Concealed / pre-wall basin waste conections in the Fittings & Pipes area at

  1. Neil Davenport

    Neil Davenport New Member


    I am renovating a bathroom and seeking advice regarding basin waste pipe connections in concealed walls, pre-walls. Can anyone advise me what waste connection / socket is actually left in the wall in a scenario similar to this image assuming that the basin wall is internal and the waste runs vertically down inside the wall. I was hoping to have all the concealed pipes solvent weld but obviously the chrome trap pipe has to go into something?


    Any advice welcome !


  2. rpm

    rpm Trusted Plumber

    That all depends on whether it was done correctly in the first place.
  3. Neil Davenport

    Neil Davenport New Member

    Sorry for not being clear, the picture is just an example. My scenario is similar but I will be ripping out and starting again, I know will be using a chrome bottle trap and want to conceal waste pipes in the wall. I would prefer to have the concealed wastes solvent weld but it isn't clear what the the first "In wall" connection should be.
  4. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    • Like Like x 1
  5. rpm

    rpm Trusted Plumber

    Everything behind the wall should be solvent weld, the last connection (outside of the wall) will be a compression joint.
    • Agree Agree x 1
  6. SimonG

    SimonG Trusted Plumber Top Contributor!!


    Some chrome pipes come sized to fit pushfit waste.

    But I don't use pushfit.

    Or an elbow or straight compression connector.
  7. S.P.S.

    S.P.S. GSR

    That fitting is a new one on me, looks great! Will definitely be using these in the future :)
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