Fitting Air Admittance (Durgo) Valve

Discussion in 'Plumbers' Talk' started by twisty, Dec 11, 2006.

  1. twisty

    twisty New Member

    I am in the process of starting to renovate our bathroom, at present there is a three quarter length bath fitted. A pipe duct at the foot of the bath containing the stack pipe prevents me from fitting a full length bath.

    Our neighbour who has exactly the same size bathroom has managed to fit a full length bath; he has removed the pipe duct and cut the stack pipe off; removing the upper section and has fitted an Air Admittance or 'Durgo' valve to the remaining section left on top of the stack pipe underneath the bath.

    Like this :( http://www.screwfix.com/app/sfd/cat/pro.jsp?id=95531&ts=36204)

    I have had two Builders/Plumbers in recently to give quotes for various works and they have both expressed concern about fitting one of these valves as according to them in this situation the valve would need to be above the level of the toilet cistern see link: (http://www.polypipe.com/POLYPIPE/pp_html/soil/soiltech_frameset13a.html) to prevent 'back siphoning' and in fact could be illegal and against building regulations.

    Is what our neighbour done correct? Can one of these valves be fitted underneath the bath so that I can fit a full length bath or does legislation state otherwise?

    Please could you confirm who/what is right in this respect relating to installing this type of valve?
    and any workaround that may allow me to fit a full length bath.

    Many thanks
  2. --------- plumbing

    --------- plumbing New Member

    thats right it has to be above the highest level
  3. twisty

    twisty New Member

    Thanks for a quick reply

    I think you have confirmed what I already knew but hoping that there was a workaround.

    Looks like I will be sticking with a new three quarter length bath !!
  4. tomplum

    tomplum New Member

    you could reduce the pipe under your bath to 2 inch then bring that tight into the corner and above the bath , if you have the room, then fit a 2 inch dergo on that.
  5. Up4rent

    Up4rent New Member

    also I beleive i am right in saying you need building control approval before you just go ahead with this.
  6. Water Systems

    Water Systems New Member

    Use HepVo traps on the bath and basins and the AAV vale can be done away with. Look at the Hepworth site, All details are there.

    HepVo are nearly always the best solution.
  7. twisty

    twisty New Member

    Thanks for this info. I have downloaded the PDF from the Hepworth site for a closer look.
    However to fit a full length bath I will need to cut off the stack pipe so that the top of it is under the bath, which is where the AAV would have gone.
    using the HepVo traps how would this scenario work? obviously the top of the stack pipe will need to be capped off.

    Thanks
  8. Water Systems

    Water Systems New Member

    Thanks for this info. I have downloaded the PDF from
    the Hepworth site for a closer look.
    However to fit a full length bath I will need to cut
    off the stack pipe so that the top of it is under the
    bath, which is where the AAV would have gone.
    using the HepVo traps how would this scenario work?
    obviously the top of the stack pipe will need to be
    capped off.

    Just cap it off. The HepVo traps act as the AAVs. If you have a shower tray put one in that as wel. All of them.
  9. twisty

    twisty New Member

    Thanks Water Systems

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