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Discuss Joining existing waste pipe in the Plumbing Forum area at

  1. Kus

    Kus New Member

    im planning a separate shower cubicle and currently have my bath and basin joining into a 50mm waste pipe to the outside stack. Can I tee in my shower to the existing pipe. If not going to have to raise tray by 100mm due to joist layout.
  2. Harvest Fields

    Harvest Fields Trusted Plumber GSR Top Contributor!!

    2” should cope as long as you do not pull the the bath, basin and run the shower all at once. But to be honest I would probably run a seperate one as you wouldn’t want the shower tray to back fill.
  3. snowhead

    snowhead Well-Known Member

    Is it possible to take the bath out of the 2" and run new for that?

    Then join the shower to the 2"
  4. S.P.S.

    S.P.S. GSR

    Don’t fit a shower to a bath waste pipe.

    If there’s a down stream blockage, or you don’t have a great pipework set up your gonna backfil that tray.

    Many will say it works, so it’s fine, but I would never do it. Basin and shower, yes, not so bad as the volume of water is far less likely to cause an issue, but that still has to be piped well!!
  5. Darren Jackson

    Darren Jackson Plumber GSR

    I always run a new waste for a shower tray and never connect to a bath waste the vacuum caused from the bath emptying can pull the water out of the shower waste trap and bad smells from the sewers can come into the house. And there is a good chance that in the event of a blockage or there is not a very good fall that the waste / foul sewerage water could back fill in to the shower tray.
    • Funny Funny x 1
  6. Kus

    Kus New Member

    The length of 50mm to the outside wall is 1.8 metres and the shower would tee in at 1 metre before the pipe exits the walls into the soil stack. Would this still cause a problem due to the short run.
  7. Harvest Fields

    Harvest Fields Trusted Plumber GSR Top Contributor!!

    Like I said above mate. If it was my house I would run another waste or as someone else said above give the bath it’s own.
    • Like Like x 1
  8. Kus

    Kus New Member

    Thanks for the info. Think I will run a separate waste for shower
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