Horizontal Run Under Joists

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by sethamin, Feb 21, 2013.

  1. sethamin

    sethamin New Member

    Messages:
    23
    Location:
    Brooklyn, NY, United States
    I'm reconfiguring an upper floor bathroom and trying to figure out the plumbing. In particular, I want to move the toilet to the far left hand side of the bathroom; put a double vanity in the middle; and a shower stall on the right. The main stack is in the middle of the bathroom, so the toilet presents a problem, as I can't drill a large enough hole through the joists (I have true 2x9 joists, so maximum hole size is 3"). My idea is to drop the line just below the joists and run it in a soffit until I can join the main stack, which is embedded in a large brick channel in the exterior wall.

    I'm in NYC so I believe I'm under UPC. One question I have is whether I need to add a cleanout on the right hand side (I'm assuming the toilet counts as a cleanout on the left). Another one is whether than double 1/4 bend is allowable; I would assume so since it's directional, but I've never really seen anyone use one before.

    Any feedback appreciated.

    Plumbing Diagram Far.jpg Plumbing Diagram Bottom Iso.jpg Plumbing Diagram Top Iso.jpg
  2. sethamin

    sethamin New Member

    Messages:
    23
    Location:
    Brooklyn, NY, United States
    After re-reading my post, I neglected to mention that the room below does not have walls framed out (it has plaster applied directly to the brick), which is why I'm not running the pipes straight down or joining them at a 45.
  3. kreemoweet

    kreemoweet New Member

    Messages:
    371
    Location:
    Seattle. WA
    Say, those some nice drawings - better than we usually see around here. What tools were used to make them?

    UPC requires no cleanouts above 1st floor or on horiz pipes less than 5 ft long, although they may come in handy someday,
    especially on the wc drain.

    I'd use a double sweep (long turn 1/4 bend) tee where those horiz drains meet.
  4. sethamin

    sethamin New Member

    Messages:
    23
    Location:
    Brooklyn, NY, United States
    I used Sketchup. Charlotte Pipe used to publish real models for all their fittings, though they no longer seem to be available now. But if you look at some old plumbing models in Sketchup's 3D Warehouse you can cut and paste them in. I wanted to actually model it, rather than do an iso drawing, so I could see exactly how much space I was going to lose.

    So joining both branches at a double bend is okay in general? I could potentially stagger them if I drill through the joists on the right (keeping 2" the whole way) and wet vent the shower through the right hand sink (saves me a vent, too). I'm hesitant to do that since I'd have to move it a few inches out from the wall (can't drill within 2" of the edge of a joist) instead of being almost flush against the wall. Again, I'm trying to really minimize the space I'm going to lose up there.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,537
    Location:
    Cave Creek, Arizona
    Avoid any hassles. Use a double combo with a bushing on top. Install a riser with a double fixture fitting and two arms for the sinks. The shower and toilet would stay the same as the drawing shows them.
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