Missing vent?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by jbg, Jan 24, 2011.

  1. jbg

    jbg New Member

    Messages:
    6
    Location:
    Northern VA
    Hey Folks-

    Great Forum. This weekend I went to move a 2nd floor toilet 6 ft from existing spot to create an alcove for it. I opened up some of the first floor ceiling to see what I was up against. Below is what I found. Toilet is direct to 3" soil stack. The tub and shower have branch drains to the 3" soil stack which runs down the front wall of the house. Tub and shower are vented to vent stack at back corner of house. First question is, am I missing a vent for the toilet? If so, any ideas how to easily fix this?

    View attachment missing vent.pdf
    Last edited: Jan 24, 2011
  2. cacher_chick

    cacher_chick Test, Don't Guess!

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    One would need to know where and how the lavatory is attached to the system to say for sure. Many areas allow the WC to be vented through the lav.
  3. jbg

    jbg New Member

    Messages:
    6
    Location:
    Northern VA
    Thank you cacher. The 3" waste pipe starts at the 2nd floor toilet via two 45 degree angles from the toilet, then travels 8 ft horizontally, then 90 degree turn and straight down to the slab. If the Shower and tub branch drains didn't connect to the 3" waste pipe during the horizontal run, it would be a dedicated waste pipe for the toilet only. Nothing else hooks into it below or above it. Seems like the branch waste drain is the only vent for the toilet.
  4. cacher_chick

    cacher_chick Test, Don't Guess!

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    As you have drawn it, the toilet line can pull air through the tub and shower vents, but this is not a proper vent for the toilet.
  5. jbg

    jbg New Member

    Messages:
    6
    Location:
    Northern VA
    Thanks Cacher. I misspoke. After a few more openings in the ceiling one of the branches is not from the shower but the sink. So it looks like the attached. I think this is OK but not great. If I move the toilet drain to the other side of the 3" soil stack but within 3ft of the branch drain/vent am I still OK?
    View attachment Vent.bmp
  6. dlarrivee

    dlarrivee New Member

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    I don't see much wrong with your latest drawing, seems common to me.
  7. cacher_chick

    cacher_chick Test, Don't Guess!

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    What you have now drawn is what I would have expected to see.
    Not clear on where the toilet is being moved to, but it has to be upstream of the 2" coming off the lav or your vent will be broken.
  8. hj

    hj Moderator & Master Plumber Staff Member

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    As long as the "vent" is being "washed" by the lav or shower/tub the orientation of the toilet is immaterial. "Moving the toilet 6 feet" however COULD be a problem.
  9. jbg

    jbg New Member

    Messages:
    6
    Location:
    Northern VA
    Thanks Everyone. I wasn't as clear as I should have been. In that last drawing, I wanted to move the toilet to 3 ft on the other side of where that branch drain comes in. If that causes a vent issue, I guess I could move the toilet and the extend that branch drain a few more feet to come in down stream of the toilet. Would that work better? View attachment Vent.bmp
    Last edited: Jan 26, 2011
  10. cacher_chick

    cacher_chick Test, Don't Guess!

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    You need to find out what the maximum allowed distance is between the WC and it's vent.

    Should not have any 3" upstream of the WC. The tub and/or lav will not be able to clean the 3" line.
  11. dlarrivee

    dlarrivee New Member

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    Although I agree there shouldn't be 3" upstream of the w/c... I don't see it causing a huge problem, what exactly needs "washing" upstream of the w/c?
  12. jbg

    jbg New Member

    Messages:
    6
    Location:
    Northern VA
    I'll look to see if I can move the branch downstream of the WC. Thank you very much for you help on this
  13. dlarrivee

    dlarrivee New Member

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    Location:
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    That isn't what we are getting at... you've mistaken something there.

    The piping only needs to be 3" downstream of the w/c, leave your drawing the same but make sure you use 2" upstream of the wye where your w/c ties in.
  14. jbg

    jbg New Member

    Messages:
    6
    Location:
    Northern VA
    Ah. Great. That makes my life a lot easier. I really appreciate the help.
  15. Must know the total distance of the NEW 2" pipe, and its fall (drop, slope).

    Even if you do everything as said above, you can still cause a big problem. Best is to hire a Master Plumber. Next best is to leave it as is. Worst is to build something new, based upon a little bit of internet learning. If you want to go ahead and move the pipes around, you still need to answer the question in my first sentence, and a few other questions. Posting a very accurate drawing is best. Next best is posting a drawing showing distances.
  16. dlarrivee

    dlarrivee New Member

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    You're far from helpful...
  17. The Original Posting Person gets the service here. Helpful to newbies. The goal in this thread is to speak to he Original Posting Person, who has the problem.

    If you think you want to move the pipes around, changing the place where the Wye connects two drain branches or arms, you Must know the total distance of the proposed NEW pipes, and their fall (drop, slope). This is a helpful reminder. I mentioned the 2" pipe in my previous pipe because this is the one that is proposed to be longer than before.

    Some of the pieces of advice you received in earlier posts Do Not take this into account. To avoid causing a big problem, post an accurate drawing, or post again about distances.

    If another reader wants to know more, stay tuned and come back when this thread grows longer, or go read other threads about total developed length of DWV pipes.

    Hope this helps. This post reiterates my previous post. Hope you enjoyed the reminder.
  18. dlarrivee

    dlarrivee New Member

    Messages:
    1,172
    Location:
    Canada
    You're not a plumber, are you?
  19. cacher_chick

    cacher_chick Test, Don't Guess!

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    Location:
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    He is right in that the wet vent will not work if it is too long or not pitched properly.
  20. dlarrivee said to the original poster that if he moved his Wye downstream, to be sure the pipe would be 2" diameter and not 3", upstream of the new Wye.

    The thing is, one guy saying to another over the internet, just do this and that should work, isn't always going to be good advice, unless it gets checked and double-checked. Why not just let the "correcting party" have an easy time of it.

    Now, listen folks; when someone cuts in to say uh-oh, that's a good time to go silent and wait.
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