(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 12 of 12

Thread: what is up with this drain backup

Hybrid View

  1. #1
    DIY Junior Member happydude45's Avatar
    Join Date
    Nov 2009
    Location
    Ontario
    Posts
    2

    Cool what is up with this drain backup

    I have attached a diagram of the system. The basement sink drains very very slowly, and gurgles loudly when using the upper sink.

    Actions taken so far with no success:
    - snaked from basement sink to where the pipe goes into basement floor (at the red marker - i cut into it at this point and verified that there was no clog upstream to sink)
    - snaked downward 20' to 25' below ground with my 3/8" snake, came up with a bit of hair, but can't be sure if there is a clog down there.

    I am hoping the problem is a clog in the vent, otherwise it must be a clog underground??...

    thanks for your help!
    Attached Images Attached Images  

  2. #2
    Previous member
    Join Date
    Jul 2009
    Location
    North of the Mason dixon Line
    Posts
    1,150

    Default

    It's probably clogged underground and a 3/8 snake is next to useless.

  3. #3
    Forum Admin, Expert Plumber Terry's Avatar
    Join Date
    Aug 2004
    Location
    Bothell, Washington
    Posts
    14,195
    Blog Entries
    1

    Default

    You have run two sinks on the vertical without proper venting.
    Anytime you drain the top sink, it will pull water from the lower sink trap.


  4. #4
    DIY Junior Member happydude45's Avatar
    Join Date
    Nov 2009
    Location
    Ontario
    Posts
    2

    Default

    Yes I know the plumbing system is not done properly. It wasn't me, just a gift that came with the house!


    I should add that when I run lots of water in the upstairs sink, water will actually come out the lower sink drains! In other words, the air is pushing out. Later it starts gurgling "the other way" as it tries to pull air in, as the water slowly drains back down.

    does that provide more evidence for a clog underground?
    any tips on how to add a vent to improve the system?

  5. #5
    Journeyman & Gas Fitter Doherty Plumbing's Avatar
    Join Date
    Jun 2009
    Location
    Penticton, BC
    Posts
    810

    Default

    Quote Originally Posted by happydude45 View Post
    Yes I know the plumbing system is not done properly. It wasn't me, just a gift that came with the house!


    I should add that when I run lots of water in the upstairs sink, water will actually come out the lower sink drains! In other words, the air is pushing out. Later it starts gurgling "the other way" as it tries to pull air in, as the water slowly drains back down.

    does that provide more evidence for a clog underground?
    any tips on how to add a vent to improve the system?
    As long as the pipe shown coming off the top of the highest sinks connection to the stack is a vent then you're fixtures would be vented properly as far as I know about your code down there.

    You would be simply wet venting the bottom sink.

    To remedy the situation you should run a snake from the roof down through the venting and down to larger piping (like a 3 or 4" connection). Flush water through the sinks as well.

    Be careful because if you DO knock out a bunch of gunk to the lowest point on the vertical soil-or-waste stack you could create a temporary blockage at the bottom and flood out the lowest sink ... until the snake gets there.

  6. #6
    Forum Admin, Expert Plumber Terry's Avatar
    Join Date
    Aug 2004
    Location
    Bothell, Washington
    Posts
    14,195
    Blog Entries
    1

    Default

    When an upstairs sink is above a downstairs sink, on the same line, then yes, it overflows the lower sink.

    I run into that all the time with handman jobs.

    Wet venting is only allowed with fixtures on the same floor, and they need to be sized for that.

Tags for this Thread

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
  •