Tub Drains Slowly

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by froddan, Nov 6, 2007.

  1. froddan

    froddan New Member

    Messages:
    52
    I recently changed the plumbing for a tub-shower from the old galvanized pipes to ABS pipes. I changed the entire drain from the Overflow to P-trap, vent connection and past the sinks.
    Everything seems fine, I pretty much configured it in the same way the old pipes had been, but it drains pretty slowly.

    I used 1 1/2 inch pipes, and I think there is enough slope to the entire drain.
    There is certainly no clogs as the pipes are new.

    I did a test by filling a 5 gallon bucket with water, poured it into the tub, and it took 62 seconds for it to completely drain, vs only 28 seconds fror the 5 gallons to drain from my kitchen sink, which has a 1 1/4 inch pipe.
    Any idea how long it SHOULD take to drain 5 gallons? Probably not the most scientific way, but a pretty good measurement.

    It drains evenly slow (if that makes sense).
    I removed the overflow puck to see if that blocked anything, but it didn't change it at all.
    The only thing I could guess would be if it is clogged further down the pipe.
    Would "not enough slope" create this problem?

    Any suggestions would help!

    Thank you!
  2. patrick88

    patrick88 Plumber

    Messages:
    836
    Location:
    Webster Ma.
    Should be 1 1/2" or it is wrong.

    1/4" per foot should be the pitch.


  3. toolaholic

    toolaholic General Contractor Carpenter

    Messages:
    874
    Location:
    Marin Co. Ca.
    Our kitchen sinks are all 2" now. Ca.
  4. Gary Swart

    Gary Swart In the Trades

    Messages:
    7,341
    Location:
    Yakima WA
    I'd suspect a clog. A 1-1/2" drain is large enough for a tub. Even a shower will drain just fine with a 1-1/2" drain unless it becomes clogged. I see no harm in a 2" drain for the kitchen, but kitchen sink hardware is designed for 1-1/2". Bathroom basins are usually 1-1/4". Again, larger wouldn't hurt, but the sinks are designed for 1-1/4".
  5. Bosun

    Bosun New Member

    Messages:
    89
    Location:
    Minneapolis
    How long were you working on the drain?

    Was this a month-long process? I have done renovations before where some stuff further down the line "toughed-up" during the month of no use. Clog.

    Venting issues?
  6. toolaholic

    toolaholic General Contractor Carpenter

    Messages:
    874
    Location:
    Marin Co. Ca.
    Gary, no option !!

    We went 2" on kitchen sinks years ago , and that's good. Garbage disposals
    are the reason. 1 1/2" will not pass inspection. I always install an additional tapped sani-tee above ,for drain clearing on every sink.
  7. MG

    MG New Member

    Messages:
    160
    Location:
    Illinois - Near St. Louis
    Are they making sinks and disposals now that have 2" drains?

    Theoretically you should not shove large amounts of stuff down the disposal at one time...you have to give it some time to process and w/a goodly amount of water.

    Personally I'd like to redo our kitchen line to 2" but it would mean removing a section of a wall in a bathroom to get to it.
  8. froddan

    froddan New Member

    Messages:
    52
    Bosun,

    Yes, it was quite a long project, probably two weeks at least, maybe four.
    I don't think there should be any venting issues. There is a vent about a foot away from the P-trap that goes up in the attic and through the roof.
    I guess I could snake that too, if necessary.

    Thanks for your reply!
    Regardless of size in the kitchen sink, (might be 1 1/2") it drains perfectly fine, so I'm not worried about this...:)
    Would a small snake auger work through a P-trap?
    http://www.hechinger.com/hardware/t...-15-plastic-drum-auger-pistol-grip-82150.html



  9. froddan

    froddan New Member

    Messages:
    52
    One more question:

    Would the location of the P-trap affect drainage for a tub?
    For example, if the vertical drainpipe under the tub only extends 2 inches down before it reaches the P-trap, vs if the vertical pipe is longer before it reaches the P-trap?
  10. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,950
    Location:
    New England
    Not that I'm aware of. As long as the outlet is leading to a line that is sloped down with the proper slope, the depth of the p-trap isn't a big deal. There is a practical maximum, but I'm not aware of a minimum.
  11. froddan

    froddan New Member

    Messages:
    52
    Thanks!
    The slope is quite visible, and although difficult to measure, I think it is about 1/2" per foot.
    Is there a maximum distance between the tub-drain and the vent pipe?
    The tub vent is located about a foot away from the P-trap (see attached picture).

    Attached Files:

  12. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,950
    Location:
    New England
    You're well within the limits for the vent on the tub, and yes, there are limits, but it depends on the diameter of the pipe used. Don't remember the exact numbers.
  13. Herk

    Herk Plumber

    Messages:
    547
    Location:
    S.E. Idaho
    Does the tub drain have a strainer? Or is it one of the push-pull drains or a toe touch or something like that?

    Quite often, there is a strainer in the tub, then a cross below that - take off the strainer part and use needle-nose pliers to pull out the hair ball that's hanging by a couple of hairs on the cross.
  14. toolaholic

    toolaholic General Contractor Carpenter

    Messages:
    874
    Location:
    Marin Co. Ca.
    Hi M J The answer is no,of cource

    I am talking 2" sani tee and drain, for kitchen sinks.
    Like many countys ,we use the UPC , and then have our local amendments to it. It's the right thing to do ,in My opinion.
  15. froddan

    froddan New Member

    Messages:
    52
    The entire tub strainer-overflow is brand new. There is nothing in it.
    Althogh I have to say that the overflow parts seem to be a bit limited in the flow of drainage.
    I found out that for a 1 1/2 inch pipe, the vent should be the same size and be located within 3.5 feet, so you are right, I am well within those limits.
    VERY strange!!! I know I will be snaking vent and drain lines this weekend.
    Thanks again for all responses.
    I am still looking for a drainage time for 5 gallons from someones tub or sink.
    F
  16. Gary Swart

    Gary Swart In the Trades

    Messages:
    7,341
    Location:
    Yakima WA
    I still suspect a clog. Perhaps there is some drywall mud or similar that is partly clogging the drain? Maybe some other foreign material somehow got into it. I think a good augering is in order by a professional. There are undreds of thousands of tubs in the US that drain just fine with 1-1/2" pipe, so there sure seems to be something else at fault here.
  17. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,950
    Location:
    New England
    I drain probably about 40-gallons in 3-minutes or so from my tub.
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