(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 8 of 8

Thread: Double wye used for double vanity

  1. #1
    DIY Junior Member xr4ti's Avatar
    Join Date
    Dec 2008
    Location
    Wisconsin
    Posts
    26

    Default Double wye used for double vanity

    Hello everyone -

    I've been visiting my new home daily as construction progresses, and the rough plumbing started last week. I noticed that they have used double wye's in the upstairs bathrooms, both slated for double vanities. I have seen and used the double fixture fitting in past projects, so I am wondering if there is any difference here? Thanks.


  2. #2
    DIY Senior Member asktom's Avatar
    Join Date
    Nov 2009
    Location
    Victor, MT
    Posts
    460

    Default

    It should be a double fixture fitting. A double wye creates a double S trap. A double fixture fitting is made so that air in the trap arm meets the stack before the drain drops down so that a siphon cannot be created. If the trap siphons it breaks the trap seal and there is nothing between your nose and whatever gas is in the sewer. An exhaust fan in the bathroom makes the situation worse.

  3. #3
    Moderator & Master Plumber hj's Avatar
    Join Date
    Aug 2004
    Location
    Cave Creek, Arizona
    Posts
    25,633

    Default

    Doulbe Ys and 45s create "3/4 S traps" which are just as bad, and illegal, as full "S" traps. The ONLY fitting you should use is the back to back one, and NOT a sanitary cross either. A "plumber" who makes an installation like that has no concept of plumbing hydraulics and should go back to school for a season or two, if he ever went to school.
    Licensed residential and commercial plumber

  4. #4
    DIY Junior Member xr4ti's Avatar
    Join Date
    Dec 2008
    Location
    Wisconsin
    Posts
    26

    Default

    Thanks for the input, glad I asked here.

    I'll bring this up with my builder tomorrow. Rough inspection is next week and I'm not confident they will flag the fittings.

    Here's another pic. Looks like it's been bouncing around in the bottom of a DWV bin and they finally found a place to dump it. My house!
    Attached Images Attached Images  

  5. #5
    Forum Admin, Expert Plumber Terry's Avatar
    Join Date
    Aug 2004
    Location
    Bothell, Washington
    Posts
    14,201
    Blog Entries
    1

    Default

    When you combine two lavs, it requires a 2" drain.
    It should have been a 2.0" x 1.5" x 1.5" x 1.5" double fixture fitting.

    So not only is it the wrong fitting, it's also undersized.

  6. #6
    DIY Senior Member Hammerlane's Avatar
    Join Date
    Oct 2011
    Location
    Ohio
    Posts
    252

    Default

    Kind of resembles this:
    Attached Images Attached Images  

  7. #7
    DIY Senior Member Hammerlane's Avatar
    Join Date
    Oct 2011
    Location
    Ohio
    Posts
    252

    Default

    A few more
    Attached Images Attached Images   

  8. #8
    Moderator & Master Plumber hj's Avatar
    Join Date
    Aug 2004
    Location
    Cave Creek, Arizona
    Posts
    25,633

    Default

    ON my screen it looks like a 2" riser with 1 1/2" arms. IF so, it is just the wrong fitting.
    Licensed residential and commercial plumber

Similar Threads

  1. Converting single sink vanity to double vanity
    By xceebeex in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 4
    Last Post: 11-28-2011, 09:22 AM
  2. Single to Double vanity
    By mfl in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 9
    Last Post: 05-30-2011, 05:20 PM
  3. another Single Vanity to Double Vanity thread, IPC
    By tekmassa in forum IPC Plumbing Code Questions
    Replies: 12
    Last Post: 06-05-2010, 01:30 PM
  4. another Single Vanity to Double Vanity thread, IPC
    By tekmassa in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 12
    Last Post: 06-05-2010, 01:30 PM
  5. adding double vanity
    By handy novice in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 12
    Last Post: 04-07-2010, 09:49 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •