1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Drainage Options for Additional Toilet

Discussion in 'Plumbing and Central Heating' started by leccyblue, 15 Jan 2020.

  1. leccyblue

    leccyblue

    Joined:
    25 Mar 2009
    Messages:
    75
    Thanks Received:
    8
    Location:
    Lincolnshire
    Country:
    United Kingdom
    Hi All,

    We will be soon embarking on a bathroom refurb, and building on an en-suite within the footprint of the existing bathroom. We will aim to complete as much of the work ourselves as possible, and plan to notify building control and involve trades where necessary. At this stage I'm trying to spec everything up and get a feel of what is and isn't possible.

    Originally the drains in our house ran to a septic tank. We had a local ground works company connect them up to the main sewer when that became an option a few years ago.

    There will be a second toilet added in the new en-suite and I'm looking the find the best option to get it connected to the sewer.

    The existing toilet is connected to a 110mm pipe which rises up through concrete floor in the bathroom, and then goes through the wall under floor level, and into an inspection chamber.

    A little further upstream in the system is a vent pipe which runs up the side of our house wall above eaves level. Nothing discharges into this.

    Further upstream is the bathroom gully (shower / bath / sink discharge into this) and then an inspection chamber and finally the kitchen gully (sink / appliances discharge into this).

    As I see it my options are;
    • Make a new mini stack inside the bathroom into the existing 110mm pipe with an AAV at the top. Discharge both toilets into this. Not sure how tall this would need to be?
    • Core drill a new hole in the exterior wall, connect to the existing vent pipe with a 92.5 degree branch and discharge the toilet into this
    • Core drill a new hole in the exterior wall, run 110mm pipe underground and tee into the existing run with a new inspection chamber
    I've attached a layout of our drains to help.

    If anyone can advise what is and isn't possible/allowed I'd really appreciate it!

    Thanks
     

    Attached Files:

  2. Sponsored Links
  3. CBW

    CBW

    Joined:
    26 Sep 2019
    Messages:
    8,407
    Thanks Received:
    2,203
    Location:
    North
    Country:
    United Kingdom
    Is the vent pipe 110mm?
     
  4. leccyblue

    leccyblue

    Joined:
    25 Mar 2009
    Messages:
    75
    Thanks Received:
    8
    Location:
    Lincolnshire
    Country:
    United Kingdom
    Sorry, yes I should have said that. It is indeed 110mm.
     
    • Like Like x 1
  5. Ian H

    Ian H

    Joined:
    14 Sep 2010
    Messages:
    7,026
    Thanks Received:
    853
    Location:
    Rochdale
    Country:
    United Kingdom
    I’d go into the vent but i’d CCTV it first or if I didn’t have a camera maybe a massive flow test.
     
  6. CBW

    CBW

    Joined:
    26 Sep 2019
    Messages:
    8,407
    Thanks Received:
    2,203
    Location:
    North
    Country:
    United Kingdom
    Agree with Ian on this, just make sure it’s suitable to be used carrying out a flow test. Obviously make sure that it’s still vented, and it’ll be like a standard stack then.
     
    • Thanks Thanks x 1
  7. Sponsored Links
  8. leccyblue

    leccyblue

    Joined:
    25 Mar 2009
    Messages:
    75
    Thanks Received:
    8
    Location:
    Lincolnshire
    Country:
    United Kingdom
    That's great, thank you both. This is probably the most straightforward option too so I'm pleased it's doable.

    Will go out later tonight and investigate. I need to double check it flows downstream too as the direction of flow and fall direction reversed when we moved to mains drainage. I hope the contractors reversed the tee that the vent pipe connects to!
     
  9. leccyblue

    leccyblue

    Joined:
    25 Mar 2009
    Messages:
    75
    Thanks Received:
    8
    Location:
    Lincolnshire
    Country:
    United Kingdom
    All checked; flows absolutely fine and in the right direction. Shoved a hose down there for good measure and it appears further downstream at the chamber.

    Thanks for your advice!
     
    • Thanks Thanks x 1
  10. Nige F

    Nige F

    Joined:
    28 Jun 2005
    Messages:
    21,197
    Thanks Received:
    1,741
    Country:
    United Kingdom
    Maybe a massive turd test - the Tee underground could be a T shape or even a Y facing the wrong way - We've all had scenarios where a softie flies and sticks like.... to an opposite wall of underground drainage. OP I don't want to P on your parade, but I would dig or cctv and find exactly what you have there. You would be surprised @ the velocity of water/solids exiting a bend @ the bottom of a stack.;)
     
    • Like Like x 2
    • Thanks Thanks x 1
  11. Hugh Jaleak

    Hugh Jaleak

    Joined:
    3 Feb 2008
    Messages:
    7,332
    Thanks Received:
    1,720
    Location:
    Northamptonshire
    Country:
    United Kingdom
    I'd be putting an access point in at the bottom of the stack too, just in case.... The last thing you need is the drain to block and a full stack to try and unblock.
     
    • Like Like x 1
  12. DIYnot Local

    DIYnot Local

    Joined:
    3 Sep 2019
    Country:
    United Kingdom

    If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

    Select the supplier or trade you require, enter your location to begin your search.


    Are you a trade or supplier? You can create your listing free at DIYnot Local

     
Loading...

Share This Page