Swap Toilet and Shower Locations

Discussion in 'Remodel Forum & Blog' started by 2BPS, Mar 18, 2013.

  1. 2BPS

    2BPS New Member

    Messages:
    7
    Location:
    Sequim, WA
    I'm doing a bathroom remodel in which I plan to swap the locations of the toilet and the shower. All of my DWV is ABS and it is located in an accessible crawl space below my single story house. I believe the swap is going to be pretty straightforward but wanted to make sure I'm not missing something.

    In this post I will ask about the drain for the new shower. Here is a photo of the existing toilet and lavatory drain. The toilet is 3" on the right, then meets the 2" vent which is also the lavatory drain. Then it flows west to my septic tank.

    IMG_0591.jpg

    Now I want to remove the toilet and put a shower drain in its place. Assuming the maximum dimension to the vent is not exceeded, is there anything wrong with doing it this way? I'm hoping I can still use the same shared vent (shared with the lavatory) for venting my new shower and not have to vent it separately.

    What's the cleanest way to tie in the new shower drain? It will be 2" ABS. What fitting(s) would you recommend to transition the new 2" shower drain into that existing 3" line (where the toilet currently connects)? The new shower drain will be in the same N-S plane as the toilet drain, but about 18" farther south (away from concrete foundation) than the existing toilet drain.

    Thank you for any input/advice.

    Heidi
  2. Terry

    Terry Administrator Staff Member

    Messages:
    15,111
    Location:
    Bothell, Washington
    You could place a santee on the 45 section of pipe for the shower if it's within 60"

    The 45 degree pipe is considered vertical.
  3. 2BPS

    2BPS New Member

    Messages:
    7
    Location:
    Sequim, WA
    Terry,

    MUST the new shower drain tie in to the 2" vent (vertical or 45 deg) or would it also be acceptable to tie in farther east, into that horizontal 3" line that currently services the toilet?

    Thanks,
    Heidi
    Last edited: Mar 18, 2013
  4. Terry

    Terry Administrator Staff Member

    Messages:
    15,111
    Location:
    Bothell, Washington
    That depends on what you are doing with the toilet.
    If the shower is the only fixture, then yes you can cut in a p-trap for the shower there.
    The lav still wet vents it as long as nothing like a toilet comes between it and the shower.
  5. 2BPS

    2BPS New Member

    Messages:
    7
    Location:
    Sequim, WA
    HOORAY! This is the answer I was hoping for.

    The toilet will be elsewhere and has its own vent. So it will just be the shower then the lav (both sharing the lav vent).

    Thank you so much!
    Heidi

    (P.S. I really don't understand why my current setup, with toilet upstream of lav, was allowed. :confused: I thought that was forbidden.)
  6. Terry

    Terry Administrator Staff Member

    Messages:
    15,111
    Location:
    Bothell, Washington
    The lav wet vents the toilet.
  7. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,128
    Location:
    New England
    A properly vented trap can have nearly anything pass by it without problems as long as the pipe sizing is correct and the proper fittings and slope are used (IOW, installed correctly!).
  8. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,812
    Location:
    Cave Creek, Arizona
    A 3x2 reducer in the horizonal pipe just before the lavatory connection and from there "level" to the shower "P" trap will be adequate. You CANNOT elevate the shower line between the lavatory and shower "P" trap, unless you install a separate vent for the shower. Architects and designers are seldom considerate enough to ALWAYS put the toilet where DIYers think they should be, which is why we put toilets upstream OR downstream from other things.
  9. 2BPS

    2BPS New Member

    Messages:
    7
    Location:
    Sequim, WA
    Thanks for the great information Terry, Jim, and HJ. I must admit I do not fully understand the logic of the venting do's and don'ts so I very much appreciate the clarification on how to apply the rules.

    HJ, I definitely did not know that about the height of the shower P-trap and not having it elevated above the tie in to the existing 3" line, so thank you VERY MUCH for calling that to my attention.

    This is how I interpreted what you said and how I plan to do it. Correct?
    new shower drain.JPG

    There isn't anything wrong with the current toilet location. I just want a bigger shower and the toilet is taking up more than its share of limited real estate in the small L-shaped room, hence the rearrangement to put the toilet in the small leg of the L and the shower in the big leg of the L. Also the door to our bathroom is never closed...and after I put in all the work to design a build a beautiful tiled shower, I would prefer to look at that rather than stare at the loo through the open bathroom door!
  10. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,812
    Location:
    Cave Creek, Arizona
    quote; hence the rearrangement to put the toilet in the small leg of the L

    Your "shower" piping is good, but WHERE is the toilet going, since you do not show the "small leg of the L"?
  11. 2BPS

    2BPS New Member

    Messages:
    7
    Location:
    Sequim, WA
    HJ--thank you for verifying my shower piping. The existing shower has its own separate vent now. I plan to remove that shower and use that to vent the toilet in its new location.

    Existing shower drain/vent (the existing toilet/lav plumbing discussed earlier in this thread joins in off the left side of the photo):
    IMG_0588.jpg

    Here is my plan for putting in the new toilet drain to replace the shower. Do you see any problems with this?
    new toilet drain.JPG

    I really appreciate the help. :)

    Heidi
  12. Terry

    Terry Administrator Staff Member

    Messages:
    15,111
    Location:
    Bothell, Washington
    Except for using the old shower's 1.5" vent, that would work. Washington code for the toilet is 2".
    In Canada they allow 1.5" on the toilet. Just think of yourself as being across the water in Victoria.
  13. 2BPS

    2BPS New Member

    Messages:
    7
    Location:
    Sequim, WA
    Terry, Uh oh, that's a really good point about vent size! I'm so glad you brought it up. I believe the vent is 2" already...but now I'm wondering. I will crawl back down under the house and check. Maybe I'll be lucky. I suppose it would not be too big a deal to change the vent to 2" if it's not already. I have reasonably good access in the crawl space below and the attic above, and I will have that wall opened up (but of course I would prefer to not mess with it).

    Or maybe some other simpler solution will present itself once I'm down there, now that I have a better idea what to look for.

    Thanks very much.
    Heidi from "South of Victoria" (just kidding...I will do it to WA code :))
  14. 2BPS

    2BPS New Member

    Messages:
    7
    Location:
    Sequim, WA
    Drat, you were right, that vent is only 1-1/2". Back to the drawing board...

    (glad you mentioned it though Terry)
  15. JP's dad

    JP's dad New Member

    Messages:
    4
    Location:
    Missouri
    Variation on this same topic

    I am remodeling an old 2nd floor bathroom and want to put the tub on the same branch as the toilet. See the picture below.
    2nd Floor Soil plumbing.jpg
    I want to put the toilet between the tub and the tub drain. I was thinking of using a long sweep with a low heel inlet to connect the tub to the toilet and then the toilet to the stack. There is a separate vent line by the tub already, so that won’t be an issue. It is OK code in Kansas City. My question is whether this works well or not – I have read that if the toilet is not always at the end of a branch, low volume toilets tend not to get sufficient suction to pull waste all the way through the toilet’s trap. There really isn’t enough clearance to put a wye fitting between the closet bend itself and the stack Tee to connect the tub on the “dirty†side. Any thoughts?
    Thanks
  16. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,249
    Location:
    Land of Cheese
    JP's dad, you should start a new post instead of adding to this existing one. What you have drawn is not correct and would not be allowed, but again, it would be best to start a new thread of posts rather than to hijack someone else's thread.
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