Using vent stack as sewage drain

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Michal kr, Oct 31, 2020.

  1. Michal kr

    Michal kr New Member

    Joined:
    Oct 31, 2020
    Location:
    Singapore
    Hey guys,
    I’m building an extension at the back of my house, where I want to add a toilet. There is no sewage pipe there, however there’s a 4 inch pvc vent stack, going from the building drain directly to the roof, with bothing else connected to it. Is it possible to plug into the vent and use it for toilet sewage?
     

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  2. Jeff H Young

    Jeff H Young In the Trades

    Joined:
    Feb 27, 2020
    Location:
    92346
    odd to have a vent like that its might be a a roof drain?. looks like your in a differant country where things could be very differant than the USA.
     
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  4. Terry

    Terry Administrator Staff Member

    Joined:
    Aug 17, 2004
    Occupation:
    Plumber
    Location:
    Bothell, Washington
    Normally once a vent, always a vent. Dropping waste from a story above can siphon traps in floors below. And there is no telling how the fittings were put together below the concrete. I would hesitate to plan for a working bathroom there when it may not work afterwards.

    The best bet is to connect where the lower floor waste lines are, and not to use a dry vent for waste above.

    [​IMG]
     
  5. Jeff H Young

    Jeff H Young In the Trades

    Joined:
    Feb 27, 2020
    Location:
    92346
    is this in singapore? I agree with Terry, however It dosent look like a vent to me I never run a vent like that
     
  6. Michal kr

    Michal kr New Member

    Joined:
    Oct 31, 2020
    Location:
    Singapore
    You guys were right, i checked my roof and this is a water drain. Curiously there is an airvent nearby that is also ran outside and looks identical. However, it’s a lot harder to access, so instead I will opt for a saniflo toilet and pump the waste to second floor, then connect it to the same drain as the toilet bowl.
     
    Last edited: Nov 3, 2020
    Jeff H Young likes this.
  7. Michal kr

    Michal kr New Member

    Joined:
    Oct 31, 2020
    Location:
    Singapore
    Running into a other issue, not sure if I should start a new thread or ask here? So, I’ll be pumping the slurry from the saniflo macerator up and back into my bathroom or kitchen. Unfortunately the main drain under toilet is not exposed, the plumber suggest raising the toilet which I’d definitely prefer to avoid. The only solution I see is to drain into the bathtub drain. Wouldnit work? Is there a P trap burriednin the cement? And how could I check if there is one? Thanks in advance!
     

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  8. Jeff H Young

    Jeff H Young In the Trades

    Joined:
    Feb 27, 2020
    Location:
    92346
    anything will work. poop runs downhill . unless you pump it, if pumped it can go anywhere you want. But my opinion is do it right! gravity drain if possible!
     
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