Adding bathroom in large loft style attic. Vent pipe needed?

Discussion in 'Toilet Forum discussions' started by Myke_Weekend_Warrior, Apr 25, 2008.

  1. Myke_Weekend_Warrior

    Myke_Weekend_Warrior New Member

    Messages:
    10
    Hello All,

    I have a three story building that currently has a toliet on the 1st and 2nd stories. There is a large attic that I'm going to add a bathroom to.

    Both toliets on the 1st and second story are hooked up to the same 4" poopie stack, and I plan to ti the 3rd story tolit into the poopie stack also.

    My question is about what I have to do, and how to do it.

    I am ok with cutting the cast iron stack, adding a 45 degree 4" booted T-pipe off the main stack, and add the flange for the added toliet in the position where I want the toliet.

    Is there anything else that I have to do with the drain for the toliet? i.e. do I need to do anything with vents, etc. to prevent water from flying out of the toliets on the 1st or 2nd floor or anything?


    Please help. :)
  2. Cookie

    Cookie .

    Messages:
    5,658
    Location:
    .
    Hello,

    Unfortunately, you cannot do what you are planning on doing. Unless, the second floor toilet is vented separately from the stack, which it won't be.
    You will have to run a separate drain line from the third floor toilet into the basement. Or, at least below the second floor toilet. But, really you need a plumber to come and look because we cannot see how the plumbing is run.
  3. taysan

    taysan Member

    Messages:
    113
    Location:
    Toronto, ON Canada
    Sounds like it would be easier to vent the 2nd floor toilet separately through the roof given the to-be 3rd floor is an attic right now.

    Pics / diagrams!
  4. Myke_Weekend_Warrior

    Myke_Weekend_Warrior New Member

    Messages:
    10
    OK - See the diagram.

    (Wow.. you guys are quick!)

    Attached Files:

  5. Myke_Weekend_Warrior

    Myke_Weekend_Warrior New Member

    Messages:
    10
    More info...

    So that there is no confusion, both the 1st and 2nd story toilets are on the same main 4" stack, both set up in the same configuration. thanks again. :)
  6. Myke_Weekend_Warrior

    Myke_Weekend_Warrior New Member

    Messages:
    10
    My Plan....

    Ok, so I plan to do the toilet on the 3rd floor in the same configuration as the ones on the 1st and 2nd floors... will it work? If not, what will happen, and why?

    I appreciate all the help.
  7. Terry

    Terry Administrator Staff Member

    Messages:
    15,416
    Location:
    Bothell, Washington
    [​IMG]
    You can't run waste down a vent.
    Doing so will siphon out all the traps below, and most of the time, they fittings on vents may not even be close to what you would need for a waste line.
  8. Cass

    Cass Plumber

    Messages:
    5,980
    Location:
    Ohio
    Like Cookie said, you really do need a plumber to come out and look at what you have and what you want to do.

    If the plumbing is as you describe it is nothing I have ever seen and is wrong.
  9. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    In your drawing, the large pipe rising from the second floor towards the attic is presently the vent for the toilets on 1st and 2nd floor. If you turn that pipe into a soil pipe, by putting a toilet on the 3rd floor, that pipe can no longer serve as a vent. Vent pipes from the first and second floor must rise separately and connect back to that large pipe 6" above the highest fixture on the 3rd floor.
  10. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,247
    Location:
    Cave Creek, Arizona
    stack

    How the first floor toilet is connected to the stack is important to the discussion, since it would normally have an offset fitting with the vent as part of it. The second floor would not have the same fitting, although it could look similar outwardly. If so, then you would have to provide a vent for the second floor toilet, not easily done, and disconnect the vent connection from the second floor and reattach it at the same relative point on the third floor. You are not looking at a DIY job, and even an experienced plumber might be challenged depending on the situation.
  11. Myke_Weekend_Warrior

    Myke_Weekend_Warrior New Member

    Messages:
    10
    Spent more time looking at actual plumbing... Here it is.

    Here is an updated drawing of the actual plumbing.

    Attached Files:

  12. Myke_Weekend_Warrior

    Myke_Weekend_Warrior New Member

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    10
    Can I do it this way?

    Can I do it this way?

    Attached Files:

  13. Myke_Weekend_Warrior

    Myke_Weekend_Warrior New Member

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    10
    Would this work?

    Ok - how about this setup....

    Attached Files:

  14. Myke_Weekend_Warrior

    Myke_Weekend_Warrior New Member

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    10
    Or Do I Need To Do Lots O Work?

    Or Do I Need To Do Lots Of Work?????

    Attached Files:

  15. Terry

    Terry Administrator Staff Member

    Messages:
    15,416
    Location:
    Bothell, Washington
    As long as you are dumping waste into a pipe, it's a waste stack, and not usable as a vent.

    You can tee off as many times as you like, as long as you are adding a vent each time,
    Those vents can tie together at six inches above the flood level of the fixtures served.
    And then that vent stack can go through the roof on it's own, or tie in above the highest fixture in the home on the top floor.
  16. Myke_Weekend_Warrior

    Myke_Weekend_Warrior New Member

    Messages:
    10
    THE PLAN... {based on your input}

    OK - so based on the input from everyone here, is shown.

    One question: If I'm draining water from a sink down a drain, can I tee off of this drain and us it as a vent? See attached. Thank you again. :)

    Attached Files:

  17. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,247
    Location:
    Cave Creek, Arizona
    vents

    I am sure your drawings are very illustrative to you, but to us we have to depend on your descriptions and so far I have not seen anything that tells me HOW the second floor toilet is currently vented. How that is done would determine what has to be done to install a third floor bathroom.
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