Drain size for tub/shower combination

Discussion in 'Shower & Bathtub Forum & Blog' started by Home Girl, Nov 23, 2009.

  1. Home Girl

    Home Girl New Member

    Joined:
    Nov 11, 2009
    Location:
    Vacaville, CA
    I am reading that the tub drain should be 1 1/2" while a shower drain should be 2". If a tub/shower combo is installed, can a standard tub drain be used, or does that require a larger shower drain?
     
  2. FloridaOrange

    FloridaOrange Plumbing Designer

    Joined:
    Dec 2, 2005
    Occupation:
    Plumbing Designer
    Location:
    SW Florida
    What do you mean by tub/shower combo? Tub with a shower head? If so the 1-1/2" drain will work. The idea is that the tub can provide holding space for water if the drain is slow, a shower doesn't offer much if any holding before you overflow the curb.
     
  3. Sponsor

    Sponsor Paid Advertisement

     
  4. geniescience

    geniescience Homeowner

    Joined:
    Nov 27, 2005
    Occupation:
    ditto
    Location:
    humid summers hot, humid winters cold
    The smaller size drain works.

    It also works for showers too, and that used to be the size required by "Code" too. I think that bigger houses and longer distances are the reasons why its size was increased to 2".
     
  5. Inspektor Ludwig

    Inspektor Ludwig Journeyman/Inspector

    Joined:
    May 11, 2006
    Location:
    In the good ol' UPC
    Yes, you can have an 1 1/2 drain for tub/shower combo.
     
  6. hj

    hj Moderator & Master Plumber Staff Member

    Joined:
    Aug 31, 2004
    Occupation:
    Plumber
    Location:
    Cave Creek, Arizona
    1 1/2"

    You are too young to remember when a shower was permitted to have a 1 1/2" drain. I am also.
     
  7. FloridaOrange

    FloridaOrange Plumbing Designer

    Joined:
    Dec 2, 2005
    Occupation:
    Plumbing Designer
    Location:
    SW Florida
    Florida used to require all under slab plumbing to be minimum 2". Now they don't, along with allowing CVPC (with joints) underslab....
     
  8. plumbergreg

    plumbergreg New Member

    Joined:
    Jun 26, 2009
    Location:
    Ontario, Canada
    The sizes in the code are the minimum size not the required size;)
     
Similar Threads: Drain size
Forum Title Date
Shower & Bathtub Forum & Blog Question on trip lever tub drain-bucket size universal? Aug 31, 2014
Shower & Bathtub Forum & Blog What to look for in a clamping drain - Weep Holes, Size, Material & cUPC Approvals Dec 14, 2013
Shower & Bathtub Forum & Blog Shower Drain Size and Code Feb 17, 2012
Shower & Bathtub Forum & Blog drain and overflow hole size and compatability of tub waste /drain Aug 6, 2011
Shower & Bathtub Forum & Blog Shower Install -- How Downsize Existing Drain Hole Siize Jan 19, 2010

Share This Page