bathroom drain help

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by Jwhitman, Jun 12, 2012.

  1. Jwhitman

    Jwhitman New Member

    Messages:
    20
    Location:
    California
    I do not understand the sizing on drains. I have a sink with 1-3/4" drain hole in it. What size is the correct drain asy diameter to put into the drain hole. I read a standard drain was 1-1/4" but that must not really reflect the sink hole. Because when I measured sink drains in the store the standard seemed to be 1-1/2". When I measured the stem of a standard drain asy the OD was approx. 1.30". So with this mind I am thinking the right drain asy I need should have an OD of 1-1/2" or slightly larger. Please help I just want to do the job right and not just make it work.
    Thanks for the information I really appreciate it.
    J
  2. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    Lavatory drain assemblies are ALL 1 1/4". That number refers to the outside diameter of the tube that ultimately connects to the trap below. The pipe which drops through the hole in the sink is naturally somewhat larger, and of course the flange on the top is much larger.

    Unless you have an "oddball" sink, either an import or some high-end foo-foo designer gizmo that needs a custom drain, virtually ANY drain assembly from ANY faucet brand, will fit ANY sink.

    The problem with plumbing is that nothing is ever 100%. There are no absolute standards.

    What brand/model is the sink? Did the drain come with the faucet ( what brand ) or is it an off-the-shelf generic drain assembly?
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,537
    Location:
    Cave Creek, Arizona
    You may be trying to make the situation much more difficult than it is. Almost ALL bathroom sink drains are the proper size for ALL bathroom sinks, unless you have one with a special sized opening, in which case you will ONLY get the proper drain from the company which made the sink.
  4. Jwhitman

    Jwhitman New Member

    Messages:
    20
    Location:
    California
    The sink is a pedestal from Kohler the Memoirs Stately model 2345-8. The faucet I installed was a Moen Caldwell CA84440.

    The the hole in the sink is 1-3/4" .Is this standard? Called Kohler and they said that model sink used a standard drain. I measured a bunch of sinks in the store and most had 1-1/2" drain holes a few pedestal and odd sinks where 1-3/4"

    Should I just use silicone to seal it? I really have no idea what to do next. Thanks for the advice so far.

    J
  5. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,137
    Location:
    Maine
    Install the faucet and drain assembly per the manufacturers instructions, which I doubt say anything about silicone. The drain assemble has wiggle room built in. Plumbers putty under the part that you can see in the sink is all you need.
  6. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,537
    Location:
    Cave Creek, Arizona
    You do NOT measure other sinks, you measure the drain fitting you are going to use. If the top flange and the bottom rubber gasket are larger then your drain hole it will work.
  7. DIYPlumber90

    DIYPlumber90 New Member

    Messages:
    15
    Location:
    CA
    Sounds like the most practical use.
  8. bigjohn2012

    bigjohn2012 Big Canadian

    Messages:
    3
    Location:
    Brampton Ontario Canada
    hey Jwhitman,

    I had the same issue - wasted so much time wondering what was happening and measuring other sinks. HJès advise is the best - wish i would have done that sooner
  9. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,537
    Location:
    Cave Creek, Arizona
    quote; it is not easy to find suitable plumbing service without looking at internet.

    Well, I would be useless to you because I do not service India, but even here, you have to search to find me on the Internet, although people do manage to do it.
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