swap double sink with bathtub

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by ThomasCrapper, Apr 12, 2007.

  1. ThomasCrapper

    ThomasCrapper New Member

    Can I use the drain(s) from an existing double sink set-up for a shower stall and a soaking tub?

    Also, is it possible to tie a double sink drain system into an existing tub drain.

    So basically, I want to switch the locations of the sinks and tub and i want to add a shower stall

    I do not know the drain sizes. For now, I'm just looking to find out if it's possible and if so, how difficult it might be.

    Here is an example of the shower/tub layout ONLY that i'm looking for. the sink would be on the back wall instead of on the right as shown.


    -Thanks in advance
  2. pipe diameter is 1-1/2" for a sink, a tub or a tub-shower. It's 2" for a shower.

  3. you can do it

    you can jsut about do anything if you want to
    fork out the money.....

    its no big deal......it all depends on the $$ signs....
  4. ThomasCrapper

    ThomasCrapper New Member


    It CAN be done?

    am i looking at:

    $100's $1000's $10,000's ?
  5. jimbo

    jimbo Plumber

    San Diego
    Since the sink drain is now probably in the wall, and a new trap will have to be located below grade and stubbed out under the tub or shower, you are probably looking at a new floor. You didn't mention if this was slab, or upper story. Since we can't see where all the pipes are in the walls now, it is hard to guestimate. There is quite a bit of work here. It certainly can be done.
  6. hj

    hj Moderator & Master Plumber Staff Member

    Cave Creek, Arizona

    The degreee of difficulty will depend ENTIRELY on how the existing piping is installed. It could range from fairly minor, to a complete remodeling job.
  7. ThomasCrapper

    ThomasCrapper New Member

    This is a 2nd floor bathroom. i feel i can re do the floor myself after all is said and done.
    I would like to try and do the plumbing myself, but i think i'll leave that to the pro's.
    i'll probably save money using a plumber!

    For all you plumbers out there, if i have the floor ripped up to expose the sub-floor,
    and the sinks and tub already ripped out, how long (roughly) should it take someone
    to re-route the pipes assuming it's a middle of the road job as far as complexity is concerned?

    Lastly, what's the average hourly $ rate i should expect to pay for this?

    Thanks for all the replies so far...
  8. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    New England
    Without knowing where the pipes currently run, you can't say. You might have to either take off the subfloor, or remove the ceiling below. Safer to remove the ceiling since you can't fall through that - gravity...

    Depending on which way the joists go, and where the current drain pipes are, you might need to run the line below the ceiling to obtain the proper slope. Also, there is a limit on where and how big you can cut holes in joists.

    You really can't tell until you know all of the variables.

    FWIW, when I had a tub relocated and a toilet moved, it cost me about $1400 but they didn't have to run all new stuff, only moved some and ran new water lines. I installed the toilet flange once I finished the floor and the shutoffs and drain once the vanity was installed.
  9. Gary Swart

    Gary Swart In the Trades

    Yakima WA
    What these pros are trying to gently tell you is that there is no way to give even a ballpark guess without physically examining the job. There are just too many variables that can come into play. Of course it might be quite simple, but it very well could be a fairly major (aka "expensive") job, and it is one you would certainly want done right. Therefore, it would be my advise to call two or three local plumbing contractors to give you an estimate on the job. You can discuss with them how much of the job you can do and how that would affect the cost.
  10. ThomasCrapper

    ThomasCrapper New Member

    Thanks to all. Although a bit vague, this actually helps out a lot.
    At least I know it's possible and since I plan on getting it done by
    a contractor anyway, the next obvious step is to get the quotes.

    I'll keep you all posted, and i'm sure i'll have plenty more questions
    throughout the next couple months.

  11. "How much will it cost me?"

    Your main question is "How Much?". Your second question is "Can I Do Some or How Much Of This?"

    Answer the various Q's posed to you, and if you do not insist that now you deserve to have your main Question answered, you'll do fine here. You'll learn a lot fast. It's really easy; later you'll admit that the information asked of you was totally necessary, and that you needed to know it yourself.

    Re-reading the questions that were implicitly asked by other posts above, I'll rephrase them for you.
    -- Which way do the joists go?
    -- Where is the "stack"? That is the main drain going down to the lower level and then out to the street.

    Answer these two questions slowly and carefully, so that it becomes clear to all who read the answers how the physical space is laid out. Diagrams help. A lot. With no diagram, there WILL be more questions.

    It's numbskull-simple once you know that this is important stuff to spell out for experienced people to take into consideration. It's in your best interest to know at least what is important to specify. If you bring someone in to your space and they get the impression that you don't even know that a joist might be something important, you might be opening yourself up to a real big emotional rollercoaster ride when they 1. lowball the estimate, 2. start the job and 3. then start saying, "now that we have uncovered the following... we now know we have to do something additional here ..."

  12. ThomasCrapper

    ThomasCrapper New Member


    I haven't moved into the house yet so I am unable to answer these 2
    questions. I will follow up when I rip the floor up after I move in.

    I used to have a job doing home improvemets for a few years, so I'm not
    diving in blindly. More specifically, I tore a bathroom floor up before and
    we ran into a lot of hurdles. However, we did not move any of the fixtures
    which is why I was unsure if it could be done using the same drains.

    My questions, so far, were answered.
    can it be done - yes
    how long will it take - depends on layout and existing joists and piping
    how much - it varies but someone here paid $1400 for light modifications
    i understand that may not be what i pay becasue every situation
    is different.

    "you'll do fine here" i'm sure i will

Similar Threads: swap double
Forum Title Date
Plumbing Forum, Professional & DIY Advice Swap Disposer on dual basin sink Jan 18, 2014
Plumbing Forum, Professional & DIY Advice Remodel Q: swapping a tub location for a vanity Mar 14, 2013
Plumbing Forum, Professional & DIY Advice Swapping Toilet and Shower locations Oct 30, 2011
Plumbing Forum, Professional & DIY Advice Tub/Lav Swap- Need advice on venting! Oct 15, 2007
Plumbing Forum, Professional & DIY Advice Double lavatory not vented, gurgling, not draining well Dec 7, 2014

Share This Page