Soil stack question

Discussion in 'Plumbers' Talk' started by vaderag, Aug 9, 2019.

  1. vaderag

    vaderag New Member

    We're currently having an extension and have just noticed (due to smelling some foul odours) that it seems the builders have terminated the soil stack inside the wall.

    We have a service void basically down the side of the house and I knew that the stack was running up there but assumed it would be punched though the roof (as every other house I've lived in did)

    I don't really know much about these things, and my main concern right now is the odor, but does anyone know if this is normal to have it?

    Does building regs allow this?
  2. blarblarblarblar

    blarblarblarblar Active Member

    I think it’s now Building requirement for it to finish within the property, should have an Air admittance valve on it.
    Severntrent and vaderag like this.
  3. vaderag

    vaderag New Member

    Ah okay, fair enough! I said i didn't know much ;)
  4. Severntrent

    Severntrent Active Member

    External open vented stacks still permitted.
    If it is terminated with an air admittance valve this should be accessible.
    Alwaysworking likes this.
  5. kiaora

    kiaora Well-Known Member

  6. vaderag

    vaderag New Member


    I note it says that they should have "adequate ventillation" if terminated inside, but isn't specific on what 'adequate' is as far as I can see?
  7. kiaora

    kiaora Well-Known Member

    What they are saying, if you box in an aav, for the aav to admit air in it must be able to draw air in from its surroundings, ie vent fitted in the boxing ?

    Good luck
  8. vaderag

    vaderag New Member

    It's basically a service duct that runs from the loft down to ground floor and the aav terminates in there. The house was built in 1894 so it's not air tight by any means! Presume this is fine...?
  9. The Teach

    The Teach Well-Known Member

    No,maybe its not installed to building regs.
    maybe the odour is from elsewhere or an odour not associated with drainage,some investigating will be required :)

    good luck :)
  10. kiaora

    kiaora Well-Known Member

    That should be fine,
    The main issue with aav, is when you run hot soapy water, this can, after a while, gum up the seal, this then allows the sewer gas to leak out, and you get what I call “the Spanish bath smell”.
  11. vaderag

    vaderag New Member

    Hmm... so - what would i do in that instance? Replace it?
  12. kiaora

    kiaora Well-Known Member

    You can take it apart, and clean all the bits inside, rubber diaphragm, and some plastic rings,

    It should be ok then .

    Or just replace , depending on your diy skill ?

    Good luck

    vaderag likes this.

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