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Two bathroom basins, sharing 1 x 40mm waste - ok?

Discussion in 'Plumbing and Central Heating' started by Simes123, 6 May 2012.

  1. Simes123

    Simes123

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    As per the subject, it would be much simpler for me to run 2 x basins (main bathroom, and next door en-suite) joining via a swept tee into 1 40mm waste boss into the stack. Pipes will be 40mm throughout (unless that is unnecessary).

    Is that compliant? I know I'm best running separate wastes, but if I can use 1 boss on the stack, it will hugely simplify the boxing in task. However, I do want the install to be compliant with BRs so will do what is correct in any case. Appreciate any help - about to order the porcelain, and 2 sharing 1 will equal 2 pedestals (preferred), and 2 separate will require me to use an inset vanity basin and build a vanity unit (not preferred!).

    Thanks.
     
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  3. Dan Robinson

    Dan Robinson

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    It should be OK with the correct fall - 50mm would be better.
     
  4. muggles

    muggles

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    Maximum run on 40mm is 3 metres, if you need to go further than that you should use 50mm. Recommended fall is 44mm per metre
     
  5. Simes123

    Simes123

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    50mm just seemed a little excessive for 2 x Basins, when 32mm is ok for one. I thought going to 40mm (50% more area) would be ok. Don't think anyone makes a 50mm pedestal trap?
     
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  7. Simes123

    Simes123

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    Hi - the Run on 1 is about 1 m, and the run on the second is about 1.5m. They'd join a swept Tee about 20cm from the Stack. (The bathrooms are adjacent thru a stud wall).
     
  8. Dan Robinson

    Dan Robinson

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    The 50mm doesn't have to come all the way up.

    50mm off the stack. Then branch off into 32mm to the traps.
     
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  9. Simes123

    Simes123

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    Presume I'd only need 50mm for where they join together - ie the last 25 cm or so?
     
  10. Dan Robinson

    Dan Robinson

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    40mm will be fine then. I ththough you were talking aabout much longer runs. Just make sure the fall it good and if possible stick rodding eyes in.
     
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