Toilet venting for a bathroom remodel

Discussion in 'Remodel Forum & Blog' started by Matt W, Jul 1, 2018.

  1. Matt W

    Matt W New Member

    Joined:
    Jul 1, 2018
    Location:
    Nashville, TN
    We are doing a gut job renovation on a bathroom and we would like to move the toilet from one side of the room to the other. This will put the toilet backed up to a 2x4 wall instead of the 2x6 wet wall. The toilet will remain directly over the main 3" sewer line that runs through the house. The toilet will still be the very last fixture before the 3" sewer line makes a 90º and goes up through the roof. All other fixtures are downstream of this point and have dedicated vents.
    See image attached of the new configuration. The old toilet discharged into the vertical vent stack on the left of the diagram.
    -Is this configuration allowed? I know someplace I remember reading that a toilet cannot be downstream of its vent. Not sure if that applies in this situation being that its the last fixture. Or will it need its own vent downstream of the toilet?

    Thanks for your help.
     

    Attached Files:

  2. Terry

    Terry Administrator Staff Member

    Joined:
    Aug 17, 2004
    Occupation:
    Plumber
    Location:
    Bothell, Washington
    What do you have downstream?
    The flat vent on it's own isn't good. If there is venting downstream, that my work. A lav run with a 2" vent would wet vent a toilet.
     
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  4. Matt W

    Matt W New Member

    Joined:
    Jul 1, 2018
    Location:
    Nashville, TN
    Thanks Terry for your quick response.
    I should have given you some more info.
    Downstream of this bathroom about 20ft away is the kitchen and laundry room. They are right before the sewer line goes out to the city connection.
    The rest of the house is an addition and it was put on its own sewer line that connects to the city independently.
    This bathroom will have a Lav and walk-in shower. They will be moved from the wet wall to the back wall of the bathroom. This is over a generous crawl space so my plan was to have both the lav and shower drain into a 2" line that was going to connect just downstream of the toilet discharge. I would vent both the lav and shower with 1.5" vent up to the attic and connect it to the main sewer vent that was in the wet wall.
    The old lav and shower drained into that main vertical stack originally but with moving it to another wall it seemed best to just run a new line to the lateral sewer line.
    I have the opportunity to do this correctly (best practices) so is it best to do something like the attached to make sure this passes inspection and will not cause problems?

    Thanks again for your help.
     

    Attached Files:

  5. Terry

    Terry Administrator Staff Member

    Joined:
    Aug 17, 2004
    Occupation:
    Plumber
    Location:
    Bothell, Washington
    1.5" isn't large enough to vent the toilet. You need a 2" there.
     
  6. Matt W

    Matt W New Member

    Joined:
    Jul 1, 2018
    Location:
    Nashville, TN
    Terry, did you see that updated drawing I attached to that last post? Would the 3" line not count as a vent for the toilet in that configuration? I could change the vent for the Lav and Shower to 2" but its a very tight space above where this bathroom is located and if 1.5" was sufficient I would do that.

    Thanks again for looking at this.
     
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