Please help - Need advise on trap and venting

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by plethodon, Feb 10, 2012.

  1. plethodon

    plethodon New Member

    Messages:
    6
    Location:
    Spokane, WA
    Hello - I have what appears to be an unvented bath trap. Pic shows the current set up and what I'd like to do about it. Depicted plumbing is in my cellar. The bath drains into a 4" horizontal pipe downstream from a vertical 4" stack that goes throught the roof (single storey bldg) via a 2X6 stud wall. The horizontal runs directly below the wall. The horizontal is properly sloped and is 17" below the floor at the vent. The plan is to install a 16" trap arm (2" pipe) via a tee into the vent stack. My understanding is that I will the have to replace the tee connection between the horizontal and vent stack with a wye. A 4" vertical toilet pipe currently drains into the horizontal pipe via a tee 14" upstream from the vent stack and I plan on changing its tee into a wye as well. Does my plan allow proper venting of the bath drain and toilet? Thank you.
    !cid_image003.jpg
  2. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,312
    Location:
    Maine
    What's your reason for doing all that? If you are doing as part of a renovation then yes, take the time to change it but if you are just doing it because you have an unvented trap I suggest letting sleeping dogs lie. Its been that way for awhile so unless it gets seldom use and the trap dries out, leave it be.
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,263
    Location:
    Cave Creek, Arizona
    IF it is an exact representation of the tub drain, then it is an "S" trap and the new connection will correct it, as long as there is not an additional bathroom on the floor above it. From the way it was done, it appears to have been a DIY homeowner installation.
  4. plethodon

    plethodon New Member

    Messages:
    6
    Location:
    Spokane, WA
    Thanks

    TS and HJ: Thanks for your responses. TS: To answer your question, this is part of a renovation project. I'm replacing pipes upstream from what I've drawn in order to deal with some drain slope issues and thought I might put everything else in order. I was just unsure about proper venting of the bath drain and toilet.
  5. liquidplumber

    liquidplumber In the Trades

    Messages:
    69
    Location:
    Gastonia NC
    No, your plan does not allow for proper venting of the toilet IF in fact you have another toilet that drains upstream on the 4 inch line you are currently connected to. You would have to connect the toilet to the vent stack in the same fashion as you are connecting the tub drain. AND the tub drain would need to connect the vent stack above the new connection point of the toilet, not below
  6. plethodon

    plethodon New Member

    Messages:
    6
    Location:
    Spokane, WA
    Thanks, liquidplumber. There is no toilet upstream but there is a bathroom sink and a kitchen sink. Does the rule you mention apply to these?
  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,263
    Location:
    Cave Creek, Arizona
    If the bathroom or kitchen sink is vented, and both should be, it will vent the toilet. And once you have an independent vent for the tub you can connect it anywhere you wish to. It would only have to be "connected above the toilet connection" if it DID NOT have its own vent.
  8. liquidplumber

    liquidplumber In the Trades

    Messages:
    69
    Location:
    Gastonia NC
    Nope, you only need to individually vent a fixture if its tying directly into a drain line downsteam of a toilet. In your example, there would be no need to vent your toilet first before tying in. (as there is no toilet upstream) The line itself will serve as the vent for the toilet.

    HJ states **** And once you have an independent vent for the tub you can connect it anywhere you wish to. It would only have to be "connected above the toilet connection" if it DID NOT have its own vent.***** Which is exactly correct. In your diagram above the 4 inch vent stack would become the individual vent for the bathtub. In my earlier posts i was mentioning the upstream connection for the tub IN CASE you needed to tie the toilet into that 4 inch vent stack (to vent the toilet) before you tied it into the drain line. Make sense?
  9. plethodon

    plethodon New Member

    Messages:
    6
    Location:
    Spokane, WA
    Thank you

    Thanks to all of you for the help.
Similar Threads: Please help
Forum Title Date
Plumbing Forum, Professional & DIY Advice Cant prime my well, sandpoint, pipe inside casing Please HELP Dec 9, 2014
Plumbing Forum, Professional & DIY Advice Kitchen Faucet ID, please help Dec 4, 2014
Plumbing Forum, Professional & DIY Advice Help identify these fittings please! Dec 2, 2014
Plumbing Forum, Professional & DIY Advice Oil to Gas Conversion. Please Help Nov 10, 2014
Plumbing Forum, Professional & DIY Advice please help! why is shower valve not centered? Oct 4, 2014

Share This Page