Dev's bathroom remodel

Discussion in 'Shower & bathtub Forum & Blog' started by deveng, Apr 29, 2013.

  1. deveng

    deveng New Member

    Messages:
    3
    Location:
    SO CAL
    Doing a complete remodel of a 55 year old shower and bathroom and may have a drain issue. A bit of history. Its a non-standard shower stall size and the drain was in the front corner. I've busted out concrete to re-locate and center the drain. The hole is open from the new drain position to the old cast iron T. I've built the new 2" ABS P-trap, drain pipe and ABS to CI adapter. I just did a GPM test to make sure it worked. I can get 3/4 gallon in 15 seconds then the last 1/4 gallon takes another 15 seconds to get through! When I had the T open (see pic #3) it looked clear. The original cast iron P-trap and drain pipe were 1 1/2" and I don't ever remember it being slow or backing up in the 30 years I've lived here.

    Ive got well over a 1/4" per foot slope on the drain pipe. The adapter at the cast iron T is a threaded 1 1/2" adapter, then a 1 1/2" to 2" Fernco. The extra clamp at the cast iron T is just added leak protection. Its a cutoff of a 1 1/2 Fernco over the leftover threads.

    Is there something wrong with my build or is it likely just old slow cast iron draining?

    Dev 1.jpg 2.jpg 3.jpg
  2. asktom

    asktom Member

    Messages:
    514
    Location:
    Victor, MT
    In your bottom picture it looks like you are going from 2" down to 1 1/2", it should be 2" all the way. That means you need to change the tee. The rubber flexible coupling is also incorrect, it should be the type with a metal shield.
  3. deveng

    deveng New Member

    Messages:
    3
    Location:
    SO CAL
    I was hoping not to have to get into the T. Its a maze of pipe. Just below that T is a Y that goes off to the sink drain. All the original cast iron shower drain was 1 1/2" so I assume if I don't have clogged cast iron, its flowing the same as it did with the original 1 1/12" shower drain, right?

    Can the increase from 1 1/2" p-trap and drain to 2" actually slow the drainage because of the neck down I put in at the T? In other words, if I had put all 1 1/2" pipe and drain would it work better?
    Last edited: Apr 29, 2013
  4. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,236
    Location:
    Land of Cheese
    It is never permissible to have a reduction in the size of a drain line going downstream.

    You effectively have an 1-1/2 drain and the line cannot be more than 6' long between the trap and it's vent.
    It also cannot not be pitched more that 1/4 inch per foot between the drain and it vent, or the vent will not work.

    Even if your venting was proper, the reduction in the size of the line is disturbing flow and breaking the vent.
    Last edited: Apr 29, 2013
  5. asktom

    asktom Member

    Messages:
    514
    Location:
    Victor, MT
    If you insist on reducing the drain line, doing it on the vertical is better than on the horizonal, but not right. The distance from the trap to the vent should not be over 42". Also, there are two other things to think about: (1) it looks like the flexible clamp goes onto a cut-off galvanized nipple & galvanized should not be used below grade. That is a time bomb, it will eventually rot out. & (2) there will be no time easier (& cheaper) to do it correctly than right now.
  6. deveng

    deveng New Member

    Messages:
    3
    Location:
    SO CAL
    I found my flow problem was indeed debris in the Y just below the T where my new ABS joins. I cleaned this out and have changed all the 2" to 1.5". I've also changed that entire Fernco junction. Flow test now is at 2 gallons in less than 20 seconds (about 6 GPM). I realize 1.5" is not optimum but it will have to do. Its hard to see in the photo but there's no galvanized nipple. Its all ABS or Fernco coming out of the CI Tee. Also, the vent is less than 3' from the trap. I've now got a level shower drain (1/4"/foot slope past the trap to the T) and good water flow.
    Last edited: May 2, 2013
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