Double Sanitary Tee/Wye

Discussion in 'Remodel Forum & Blog' started by KyleBaconBits, Mar 19, 2021.

  1. KyleBaconBits

    KyleBaconBits New Member

    Joined:
    Mar 19, 2021
    Location:
    Ontario Canada
    Hi there,

    I've consulted this website many times, but never posted. Thanks for all the advice up until this point.

    I'm in the process of trying to "flatten" these two runs into the same plane so they can be framed inside 2x4 wall. I cannot build bulkhead around the whole mess, as there is a window right there. The copper AC lines will be removed, as will the red wire. This is what's holding me back. I will also be moving that vent run off the concrete, so it's more inside the house.

    I was wondering if a double wye/tee would work in this instance (or some kind of cross) to combine the drain and vents into the same run. I'm trying to eliminate the overlap in the photo.

    The other thing I could do is perhaps run the vent downwards below and around the drain into the main vent stack - but that just feels wrong.

    Please review the photos. Thank you very much for your help!

    [​IMG]

    [​IMG]
     
    Last edited: Mar 19, 2021
  2. wwhitney

    wwhitney Well-Known Member

    Joined:
    Mar 17, 2019
    Location:
    Berkeley, CA
    #1 definitely doesn't work. You can't interrupt your vent with a drain flowing through it, so you basically can't cross a drain and a vent in the same plane.

    #2 might work, I'm not familiar with the details of the Canadian Plumbing Code. One of the US plumbing codes (UPC) requires a vent to be pitched back to the drain(s) it serves, so it wouldn't allow #2. The other (IPC) just requires a vent to be pitched back to some drain, so it arguably allows #2. Where the new lower horizontal vent segment would be pitched down and to the left (so your san-tee wouldn't be upside down).

    A few more possibilities (not sure if I fully follow the overall context of your close up photo):

    - Can you jog the kitchen drain above the existing horizontal vent into the wall/floor framing behind the horizontal vent, and reach the lower vertical drain section that way?

    - Or can you jog the vent within the floor framing to come out to the left of the drain?

    - Or jog the kitchen drain to the right (possibly along with jogging the vent to the left) so they don't intersect?

    Cheers, Wayne
     
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  4. KyleBaconBits

    KyleBaconBits New Member

    Joined:
    Mar 19, 2021
    Location:
    Ontario Canada
    Hi Wayne.

    Thanks so much for your reply!

    1) Okay great - makes sense that you can't interrupt a vent with a drain. Thank you.

    2) The vertical vent on the left (which runs up through the roof) - the lower portion of that ties into a drain for the laundry basin, which ties into the main 3" drain stack (see photo below).

    The other weird thing is that the vent that I'm trying to move (from the first photo) - comes from a bathroom sink on the whole other side of the basement. The drain itself for the vent I want to move is a good 3-4 feet below the vent. Here is drawing and a photo showing more information.

    [​IMG]
    [​IMG]

    As far as jogging things behind/around - that 2x12 is sistered, and holds up the second floor (side-split). I really want to avoid cutting 2" holes in it if possible, especially so close to the foundation on which it's sitting.

    Jogging the kitchen drain to the right, I like that - but I don't really want to cut into the 3" stack to rotate the feed to the right. I also don't want to create a zig-zag of 45's and 90's where the kitchen sink goes to the right, then zigs back left into the 3" stack. I mean, if that's the way I have to do it I'll do it - but I was looking for something neater (it also just feels wrong to zig-zag a drain - I figure the less bends the better).

    *IF YOU WANT ANY MORE PHOTOS OF ANYTHING IN PARTICULAR, I'm happy to take and upload if it will help you answer my question.

    Thank you very much again.
     
  5. wwhitney

    wwhitney Well-Known Member

    Joined:
    Mar 17, 2019
    Location:
    Berkeley, CA
    In that last photo, how about the following for the kitchen drain:

    That 45 next to the wye, turn it so the inlet is facing up. Then going upstream, the drain rises up alongside the double 2x12 until it comes through the subfloor, then hits a 45 to turn up and to the left, then another 45 to hit the existing kitchen drain.

    I can't quite tell what is going on above the subfloor, whether that routing would be through an exposed area or if there are obstructions there.

    BTW, in the US at least, that rubber coupling should be a shielded rubber coupling; the unshielded kind are only rated for below ground use.

    Cheers, Wayne
     
  6. KyleBaconBits

    KyleBaconBits New Member

    Joined:
    Mar 19, 2021
    Location:
    Ontario Canada
    Awesome Wayne,

    Thanks for the advice. I appreciate it.

    That idea sounds like it will work.

    Have a great day!

    PS: I'll look into that fernco coupler code for Ontario.
     
  7. wwhitney

    wwhitney Well-Known Member

    Joined:
    Mar 17, 2019
    Location:
    Berkeley, CA
    BTW typically to make a change like this between two fixed points (the wye on the 3" stack and your kitchen drain), you'll need to end up with two rubber couplings. They could be at both ends of the new portion, or you can just start gluing up from one side and then the final piece you put in is a straight section at least 3" long with rubber couplings at each end (would need to be 4" + long with the style in your photo, vs. the 2" long shielded style I was suggesting is required).

    Given that you'll be putting in that new section with two 45s above the subfloor, you have some possibility of doing it with 1 (or 0) rubber coupling, if you have some lateral play above or below (and it would be pretty easy with longitudinal play above). You'd do that by making your last glue connection at, say, the lower 45, while simultaneously positioning your upper connection (be it glue or rubber coupling). You'd sort of rotate the leg that's at 45 degrees from vertical into place starting, simultaneously mating it above and below.

    But if you want to make it easy on yourself, stick with two (shielded) rubber couplings.

    Cheers, Wayne
     
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