WC outlet fixed into ground / AAV - outlet & connection ideas needed

Discussion in 'Plumbers' Talk' started by BazzaNew, Sep 14, 2021.

  1. BazzaNew

    BazzaNew New Member

    Hi hi

    All help appreciated. Bit of a DIY newbie, cracking on as best I can. Hopefully this makes sense.

    Renovating downstairs WC of recently purchased house. Upon ripping everything out I discovered the outlet is a fixed, angled, 110mm pipe straight into ground (concrete) with no vent as per picture.

    It is not movable/cannot be turned, and sits very close to where the toilet outlet will be. I wanted to attach a Durgo / AAV and struggling to see how to make it work.

    Option 1 - flexi pan connector with bose vent on top - through push fit connectors, attach the 32mm vent (on top of pan connector) to 40mm pipe and then to 110mm pipe for a standard sized AAV. Concern is the narrow pipes not allowing sufficient airflow from the 110mm and whether that causes problems.

    Option 2 - as above but instead of on to 110mm pipe / AAV, use a smaller AAV that fits 40mm pipe. Concern again is airflow due to smaller AAV.

    Option 3 - saw through the fixed outlet pipe below the curve to allow 110mm T-pipe to be connected via pushfit connector which hopefully sits vertically. That allows the pan connector to be attached to the side whilst leaving 110mm top opening. Concern with this (1) as far as I can see the fixed outlet in the ground is 110mm. However, once I saw through its the point of no return. If it turns out to be 100mm or 115mm etc I will need some kind of insert connector to sit inside it to connect the T-pipe. Worried about sawing that and then struggling to find what I need. (2) I need some kind of flexi connector in the tope of the T-pipe to bring the 110mm pipe that goes up to the AAV over to the corner of the room to allow room for the cistern. And generally I have no idea if these connectors exist / fit.

    lots going on there and just struggling to think how best to tackle that. All ideas much appreciated.

  2. pppmacca43

    pppmacca43 Super Member

    Is that an orange plastic fitting? Looks like one. Pull it off if so and I suspect u will have a straight piece of pipe coming out of floor.
    What makes you want an AAV? If it is connected to the same drain as the upstairs toilet it shouldnt need one.
  3. just pumps

    just pumps Screwfix Select

    What makes you think you need the aav, was there any problems and if so tell us more or are you adding a wash basin you havent mentioned.
    If you dont know the age of the silver flexi or if it simply joins two solid pipes then now would be a good time to replace it.
  4. BazzaNew

    BazzaNew New Member

    Thanks both.

    tbh thinking its better to have an AAV than not, especially whilst room is empty and starting from scratch. Mostly want to avoid possibility of blow back odour from the outlet.

    Wash basin has its own outlet (quirky old house) so that will not run into the toilet outlet.

    silver flexi pipe is the toilet water feed and will be replaced.

    orange outlet pipe appears to be properly glued or cemented in, cannot move it unfortunately
  5. pppmacca43

    pppmacca43 Super Member

    Is it orange plastic? If so it should join onto a 110mm plastic pipe coming through the floor. It’s probably just tight, and will come off with a bit of persuasion. If there wasn’t an AAV before and there was no issues I wouldn’t worry about one now tbh.
  6. BazzaNew

    BazzaNew New Member

    It is. Its cemented in and from what I can see the join is about 1ft underground. Its not budging unfortunately
  7. pppmacca43

    pppmacca43 Super Member

    It’s difficult to explain but u will be able to get the fitting off, u may need to be a bit rougher with it or even cut the fitting where it slides on to release it.
  8. kiaora

    kiaora Screwfix Select

    if the drain invert is within 1200mm no vent is required
    check out building reg H, free to download, it explains all to do with drains, interesting reading !
    good luck
    just pumps likes this.
  9. BazzaNew

    BazzaNew New Member

    Thanks again for the replies

    i think its within regulation but to be honest its more about making a nice job of it, avoiding any possible odours, whist there. Seems to be worth the effort whilst its all open?

    Because of the bend I cannot figure out the drop accurately which kind of points me towards cutting it off anyway.

    Having had a better look I can see its a 110mm, 135 degree bend, drain pipe upside down.

    inside is the 110mm straight pipe with no connector so they have put this over the top. They have cemented it in so I am erring away from breaking it out and instead just sawing it at the bend. It will be boxed in anyway.

    i have a 110mm rubber connector and a t-junction so fingers crossed that will slot straight in, allowing the pan connector on the side and the pipe to the AAV on the top

    my main concern was sawing leaves no room for error but it seems to be 110mm inside. I have tested the rubber connector on the sore 110mm pipe I have so it should work

    i hope :)


    Last edited: Sep 17, 2021 at 5:12 PM
    pppmacca43 likes this.
  10. pppmacca43

    pppmacca43 Super Member

    What you could have done is cut length ways down the part of the fitting that slides in the pipe to release it(without actually cutting the pipe)
  11. BazzaNew

    BazzaNew New Member

    Good idea did not think of that thanks

    could break it off that way couple of cuts and break it off the straight pipe inside

    Not tackled it yet still psyching myself up to it
  12. pppmacca43

    pppmacca43 Super Member

    Yep once u have made one cut all the way through the fitting it should come off fairly easy, unless an idiot has glued it on, unlikely but I have seen it. Nothing to lose by giving it a go

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