Vanity and plumbing offset for drain too low.

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by jbg_diy, Sep 14, 2020.

  1. jbg_diy

    jbg_diy New Member

    Joined:
    Aug 18, 2020
    Location:
    Houston
    D7B78E37-0C2B-47B4-B9B6-DDCD3E16C233.jpeg

    As you can see in the picture, the drain and supply line plumbing for my new vanity is off by several inches. Any advice on what to do here? The PVC drain line is connected to the old cast iron line with a fernco fitting. I believe it’s currently sloped at 1/4” per foot. I’m worried if I raise it a few inches I could have some issues. Looking forward to any advice!
     
  2. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    Hole saw comes to mind for the supply lines. Looks like you would want to do some cutting to let the drain line fit.

    Alternatives: different vanity, or open the wall and move pipes. I am not a plumber. Vanity seller may let you swap units if this is a new unit.
     
    jbg_diy likes this.
  3. Sponsor

    Sponsor Paid Advertisement

     
    jbg_diy likes this.
  4. Terry

    Terry Administrator Staff Member

    Joined:
    Aug 17, 2004
    Occupation:
    Plumber
    Location:
    Bothell, Washington
    Old plumbing for a standard vanity, and now a new taller one with a drawer below?

    This is the fix by adding more venting by way of an AAV.

    [​IMG]
     
    jbg_diy and Jeff H Young like this.
  5. jbg_diy

    jbg_diy New Member

    Joined:
    Aug 18, 2020
    Location:
    Houston
    Thanks Terry. My situation is slightly different in that the drain line is hitting the frame of the vanity. I could open the wall and raise it, but I’m worried I’ll have issues down the road with such an increased pitch. This does look like a great solution if I could somehow get it to work.
     
  6. Terry

    Terry Administrator Staff Member

    Joined:
    Aug 17, 2004
    Occupation:
    Plumber
    Location:
    Bothell, Washington
    If the pipe in the wall is vertical, I go in and raise the santee using shielded couplings.

    [​IMG]

    [​IMG]
     
    Last edited: Sep 16, 2020
  7. jbg_diy

    jbg_diy New Member

    Joined:
    Aug 18, 2020
    Location:
    Houston
    It’s actually running horizontal to the main drain/vent stack. I’d raise it but I’m concerned I’ll have issues down the road if the pitch is greater than 1/4” per foot, which it definitely will be. Would you be concerned as well about maintaining that pitch?

    [​IMG]

    [​IMG]
     
  8. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    If your horizontal pipe is pitched more than 1/4 per foot, then you will need to add a vent.

    This could be from a pipe attaching 6 inches or more above the flood level of the sink. If you are interested in doing that, good.

    Houston, unlike most of Texas, is under UPC, and they may not allow AAV vents. I don't know.

    Actually, if you are going to open a wall, you would be better off adding a new horizontal (1/4 in/ft) to a new sanitary tee. As easy, or maybe easier, than adding a vent pipe.
     
    jbg_diy likes this.
  9. jbg_diy

    jbg_diy New Member

    Joined:
    Aug 18, 2020
    Location:
    Houston
    Thanks for the info and advice. I was thinking of adding a new sanitary tee it’s just I’m dealing with a cast iron vent/drain stack :( any advice on the best way to add a new one to cast iron? Currently the pvc pipe you see is attached to the old cast iron drain with a fernco fitting.
     
  10. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    You mean other than a different vanity?

    If you cut the cast iron with a Diablo blade on a reciprocating saw, be careful to not stab through the wall on the other side. A shorter stroke can help with that.

    Support the cast iron above before cutting.

    If the new vanity will cover right against the wall that you open, it does not have to be as good of finish.

    Edit: how about getting the vanity frame reinforced somehow, and cut away the frame portion that interferes with the current drain location.
     
    Last edited: Sep 18, 2020
  11. wwhitney

    wwhitney Active Member

    Joined:
    Mar 17, 2019
    Location:
    Berkeley, CA
    Cut vanity legs to lower it?

    Cheers, Wayne
     
    jbg_diy likes this.
  12. Jeff H Young

    Jeff H Young In the Trades

    Joined:
    Feb 27, 2020
    Location:
    92346
    the line being horizontal can still be offset without touching stack an aav can still be put on the trap arm. it can exceed 1/4 per foot have 45s what ever as long as he uses the aav
     
    jbg_diy likes this.
  13. jbg_diy

    jbg_diy New Member

    Joined:
    Aug 18, 2020
    Location:
    Houston
    Thanks. Have definitely considered this and still considering this. Seems like the ideal option, but I also like the comfort height of 36”. Just trying to weigh my options at this point.
     
  14. jbg_diy

    jbg_diy New Member

    Joined:
    Aug 18, 2020
    Location:
    Houston
    I’m starting to think I should just cut the legs or get a new vanity, but it’s through Wayfair and they have the worst return policies. I appreciate the advice. I really wanted to see what my options were and ultimately make a decision soon.
     
  15. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
Similar Threads: Vanity plumbing
Forum Title Date
Plumbing Forum, Professional & DIY Advice Double (triple) vanity sink plumbing Jun 29, 2020
Plumbing Forum, Professional & DIY Advice Double Vanity Plumbing Jun 11, 2020
Plumbing Forum, Professional & DIY Advice Plumbing P-traps for double vanity Jun 10, 2020
Plumbing Forum, Professional & DIY Advice Bathroom Double Sink Vanity plumbing question/issue Apr 4, 2020
Plumbing Forum, Professional & DIY Advice Bathroom Vanity & Plumbing Pipes Feb 8, 2020

Share This Page