Bathroom venting

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by teeman11, Mar 24, 2006.

  1. teeman11

    teeman11 New Member

    Messages:
    22
    Location:
    Pennsylvania
    I have an old bathroom that I'm remodeling and I don't think the existing plumbing is vented right. It's on the top floor. The waste stack is 4" and the WC is tied right to it. From the same fitting there is a 1 1/2" pipe that goes over about 2 feet to a sink in the kitchen, continues on about a foot to the sink in the bathroom, and then contines on about another 2 feet to the tub/shower. There is no other vent except for the stack itself which goes up thru the roof.

    Is this right? or should I add a vent to one of the sinks? I'm thinking about moving the sinks so they are back to back and then venting that back to the main stack up in the ceiling before if goes thru the roof. Would that work?

    Thanx,
    T
  2. teeman11

    teeman11 New Member

    Messages:
    22
    Location:
    Pennsylvania
    more

    Well, it looks like I'm going to replace everything with new. I'm looking at coming across with 2", popping up thru the floor with 2" for a washing machine, then popping up with 1 1/2" for the back to back kicthen and bathroom sink(which would vent with 1 1/2"), and ending with the pt rap for the tub and shower.

    another thing I was looking at was popping thru the floor with a 2" for the sinks and have the washing machine tie into to that.

    I'll try to get a picture up. I see alot of people have looked at this thread but no reponses, so maybe that will help.
  3. Terry

    Terry Administrator Staff Member

    Messages:
    15,416
    Location:
    Bothell, Washington
    [​IMG]
    I'm a little confused about how you will be laying it out.
    The vents should pull off even with the trap arms.

    Reventing can be done at 6" above the highest flood level.
    Most plumbers use 42" for this measurement.

    washer needs a 2" drain and p-trap., 1.5" vent is okay
    kitchen sink needs 2" waste, 1.5" trap and arm, 1.5 vent is okay
    toilet needs 3" waste and 2" or larger vent
    tub shower needs 2" waste, p-trap at least 1.5" and in some cases 2", 1.5" vent is okay.
    Most codes would not allow a kitchen sink, tub and a washer on a 2" horizontal waste line. You could get by with a tub and a washer, or a washer and sink, but not all three.
  4. prashster

    prashster New Member

    Messages:
    941
    In general, textual descriptions of layouts are complicated and hard to follow. I'd speculate that most people are like me, and get lost very quickly in textual descriptions of 3-d geometry.

    A picture with as short a description as possible is the best way to get answers to your questions.

    So, post it!
  5. teeman11

    teeman11 New Member

    Messages:
    22
    Location:
    Pennsylvania
    finally!

    Getting a file on here is hard work. First the file was too big, fixed that then the picture itslef was too big, but I finally got it, I think.

    Attached Files:

    • 1.gif
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  6. prashster

    prashster New Member

    Messages:
    941
    How's the tub/shower vented?
  7. Terry

    Terry Administrator Staff Member

    Messages:
    15,416
    Location:
    Bothell, Washington
    The toilet arm must be above where the other fixtures tie in.
    You can't "wet vent" them over the toilet like that.

    [​IMG]
    No santees on their backs. These must be wye fittings.

    The sink and lav can be tied together using a 2"x1.5"x1.5"x1.5" fixture fitting.
    The bottom of the fitting needs to be 2", and since you have a kitchen sink there, a 2" cleanout.

    The tub shower needs it's own vent.

    The standpipe for the washer needs to be longer.

    The horizontal waste needs to be 3" until you pick up the washer, then you can go to 2".

    If you have a closed system on your water supply, you will need hammer arrestors on the washer water supply and on the dishwasher.
    Last edited: Sep 15, 2007
  8. teeman11

    teeman11 New Member

    Messages:
    22
    Location:
    Pennsylvania
    So, I could put 2 3" santee's on top of one another, the bottom for the washer run and the top for the toilet?

    Sidenote: Say I didn't put the washer in and could use a 2" horizontal, are you saying I couldn't use a santee for the toliet with a 2" side inlet because the inlet is higher than were the toliet drains in?

    I know about the washer height, just didn't come thru in the drawing, but does the washer need a vent(the dotted line) also?

    I thought the tub/shower could be wet vent thru the lav?

    Thanx for all the help. I'll post a new(corrected) pic tomorrow, software is at work.

    T
  9. teeman11

    teeman11 New Member

    Messages:
    22
    Location:
    Pennsylvania
    here's what I got.

    Attached Files:

    Last edited: Mar 28, 2006
  10. prashster

    prashster New Member

    Messages:
    941
    You can use the sanitary tees in the dry portion of the vents.

    You definitely need to vent the washing machine. It 'flushes' more water volume than a toilet, and not venting it would create a siphon that would suck out the water from its trap.
  11. Terry

    Terry Administrator Staff Member

    Messages:
    15,416
    Location:
    Bothell, Washington
    [​IMG]
    The tub vent, since it on it's back would be a wye or combo fitting.

    Like the other poster mentioned, you can use santees on the high revent.
    For the 90 els on the upper revent, I use the med 90's there.
    The sweep is the same as a santee and cost less than a "vent" tee.
    I haven't bought a "vent" tee in twenty years.
    Last edited: Sep 15, 2007
  12. teeman11

    teeman11 New Member

    Messages:
    22
    Location:
    Pennsylvania
    So the tub MUST be vented. I thought I read somewhere that you can wet vent it as long is it's within a certain distance, not true?
  13. Terry

    Terry Administrator Staff Member

    Messages:
    15,416
    Location:
    Bothell, Washington
    The tub MUST be vented.

    There are cased where you have a lav that can be wet vented, because you have gone up a pipe size.

    But you have two fixtures, one of them being a kitchen sink, which puts you over on fixture count, and the pipe size being 2" is not large enough for the wet vent in that case.

    Spending the $8 on the tub vent, is cheaper than changing the plumbing to 3" at the kitchen sink.

    In the end, it's about having traps that don't suck themselves dry and allowing smells and drains that back up into other fixtures when they drain.
  14. teeman11

    teeman11 New Member

    Messages:
    22
    Location:
    Pennsylvania
    I'm defintiely going to vent the tub I just want to make sure I know why. So if I understand correctly, if there was no kitchen sink, the tub could then be wet vented of the lav.

    oh, another thing I was still curious about, Say I didn't put the washer in and could use a 2" horizontal, are you saying I couldn't use a santee for the toliet with a 2" side inlet because the inlet is higher than were the toliet drains in?


    Thanx,
    T
  15. teeman11

    teeman11 New Member

    Messages:
    22
    Location:
    Pennsylvania
    small issue

    I don't think I have enough room between the 2nd floor ceiling and the 3rd floor floor to put two 3" santees on top of one another. Is there a way to tie the toilet into the 3" horizontal?

    Also is there a way to run the washer out the side of the lav. vertical? Meaning, run a 3" all the way to the lav, come up with a 2" but pop out the side before you get to the cross with a 2" santee to go to the washer and then tie the vent back into the lav vent up above.

    I get new pics tomorrow, but my main problem is lack of space for the two 3" santees.

    Thanx again, this forum is a huge help.
    T
  16. teeman11

    teeman11 New Member

    Messages:
    22
    Location:
    Pennsylvania
    here's the pic

    Can I do this?

    Attached Files:

  17. prashster

    prashster New Member

    Messages:
    941
    Looks like yr toilet is wet vented. No no? Why don't you just take off from the trap arm up to the main horiz vent?
    Also looks like your washer vent takes off below the trap weir. Another no no? Why'd you go roundabout like that? You must love fittings! Can't you just go straight up through the wall with the vent to the main horiz vent like with the toilet? And go straight back and down to the drain?
    Last edited: Mar 30, 2006
  18. teeman11

    teeman11 New Member

    Messages:
    22
    Location:
    Pennsylvania
    For the toilet, you're saying put a vent in inbetween the toilet and the 3" wye and take it up to the 1.5 vent run in the ceiling? Can it be 1.5"?

    Washer trap would attach to a 2x1.5x2 santee, drawing is just a little off.

    For the washer, I want to put the drain and shutoffs under the sink. I figure it would be easier to have one pipe come up thru the floor and one go up thru the ceiling, it only adds the two 90's. So instead of a wye in the floor and a santee in the ceiling I'd have a santee below the lav and a santee(inverted) above the lav.
  19. prashster

    prashster New Member

    Messages:
    941
    You lost me on the laundry part of it. But for the toilet, I'm not sure if it can be as small as 1.5. Why can't you tap into the 3" main stack vent on the vertical like the 1.5" vent does? Then it doesn't matter if the vent is 1.5 or 2 for the toil.
    Last edited: Mar 30, 2006
  20. teeman11

    teeman11 New Member

    Messages:
    22
    Location:
    Pennsylvania
    how's this? Is this what you mean by venting the toilet?

    The problem with tying into the 3" vertical vent stack is that it's not in the wall, it's in chase in the corner of the bathroom, that's why I was trying to ti in up in the ceiling.

    Attached Files:

    Last edited: Mar 30, 2006
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