Rearranging Bathroom- Venting Question

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by djn602, Nov 2, 2013.

  1. djn602

    djn602 New Member

    Messages:
    9
    Location:
    MO USA
    Hello,

    I found my bathroom to be rotten so I had to gut it. I have removed the tub and am just doing a shower. My question is in regards to venting. In the picture you see the 3 inch for the toilet on the left then a wye for the sinks then another wye for the shower and then it connects to the 3 inch vent through the roof and the 3 inch continues on. Is this OK? I have flip flopped the room so this is a change from what was there originally. Since I have installed this I have a feeling I have to vent on the toilet end,-2 inch which I would take up that interior wall and connect to the vent going through the roof. I am hoping what I have already will be OK but we shall see.

    bath.jpg
  2. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,281
    Location:
    Land of Cheese
    The sink and shower must have vertical vent take-offs prior to the connection to the main line. The sink drain would normally be done with a sanitary tee in the wall- vent goes up, drain goes down.
    The way you have it the sink is not vented, and toilet being flushed can siphon the traps of the other fixtures.

    There is a helpful publication available from Bert Polk, (a residential plumbing inspector) available here-
    http://www.co.lincoln.or.us/planning/plumbing/apps/plumbingguide.pdf
  3. djn602

    djn602 New Member

    Messages:
    9
    Location:
    MO USA
    Thanks for the link. I am going to give my thought process so I can learn, venting in situations like this are still tough for me. On the lines for the shower and sink I thought they would not need a vent since there were within five feet of the vented three inch which would wet vent them. I have the sink going through the floor because the exterior wall is 2x4 and how the wall/plates sit on the foundation will not allow me to get a vent up that wall. I then thought the 3 inch run (technically a closet bend?) being within 6-7 feet of the vent (depending on code) would be ok.

    Now looking at the pdf you linked to, that three inch run for the toilet (the closet bend?) can not have anything drain into it before it gets vented? So if I vent the 3 inch right after the toilet with a 2 inch and run it parallel and then tee into the 3 inch vertical vent would I be golden? Do I also need to vent the shower and sink runs if I do the 2 inch vent and am within the distances I described above? It would not be a big deal to put in a few more tees and vent those guys into the same 2 inch as the toilet. I think the 2x10 joist bay will give me the height to do it all.
  4. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,281
    Location:
    Land of Cheese
    The downstream stack will do nothing to stop the water closet from siphoning the other fixtures. If the minor fixtures were close enough to the stack, then they could connect o the stack via a side inlet for the stack to operate as both a drain and vent.

    Not sure what you are describing in reference to teeing in. Any fixture vent must be vertical until it is at least 42" above the floor. If you can get a proper vent on the sink, the water closet can be horizontally wet vented through the sink's vent as long as it is within the allowed distance. This is allowed only because the sink drainage is minor, but is is enough to continually wash the vent clean. Given your layout, this would be the direction I would be looking at.
    Last edited: Nov 2, 2013
  5. djn602

    djn602 New Member

    Messages:
    9
    Location:
    MO USA
    So horizontal vents are generally a no go? What about something like a shower where you would have to horizontally vent for a bit before you could go vertical?
  6. djn602

    djn602 New Member

    Messages:
    9
    Location:
    MO USA
    Sorry I read more on horizontal venting. Way too much fun.
  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,267
    Location:
    Cave Creek, Arizona
    Your sink and shower BOTH need vents, but if done correctly either one would vent the toilet. It usually has NOTHING to do with how close they are to some other vent. It is like a customer who once asked why her milk spoiled when the table was only teo feet from the refrigerator? Proximity is not always enough and does not mean proper usage.Why is the sanitary tee at the bottom of the pipe going up the wall "backwards"? We try not to vent the shower horizontally. Usually, we run the vent vertically off the shower drain when it goes under a partition. If I had installed it that way, and I probably would not have, I would not have strapped the 45 so "tight" to the joist. It should give you a hassle when it is time to install the toilet's flange, unless you intend to use an "inside the pipe" flange, which is also something I would NEVER do. Who is going to go UNDER the floor to access that cleanout on the end of the pipe?
    Last edited: Nov 3, 2013
  8. djn602

    djn602 New Member

    Messages:
    9
    Location:
    MO USA
    Well the sink is now vented and is a 2 inch run all the way.

    I thought venting could be distance dependent using the fixture arm rules? I thought the 3 inch was the vented stack so the other items would not need to be vented using fixture arm rules. Live and learn. The toilet being on the end changes all that.

    It would be a pain to use but the clean out is there. I have several under my house so I just went with it. As for the tee I did not give it much thought since it was venting and is so large.

    The output of the shower trap is 12 inches from the 3 inch. Do I still need to vent it now that the sink is venting the toilet? In hind sight I should have run the shower 2 inch parallel to the 3 inch and then I could have easily vertically tied it into the 3 inch vent it as it passed under the 2x6 wall. If what I have planned with not work then I will cap that wye shown and insert one downstream and vent as stated.

    Thanks much. I have much respect for your profession.
  9. asktom

    asktom Member

    Messages:
    589
    Location:
    Victor, MT
    Where the 3" vent comes up you have a san tee in backwards, it should be a combination with the sweep going the other way if you are under the UPC. Also, the 3" is flat under the floor, it should go up at a 45 or more vertical.
  10. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,313
    Location:
    Maine
    The clean out under the toilet doesn't meet code either. It needs 18" clearance from objects. The way it is now is pretty much useless. The 3" sanitary tee is installed backwards. If the 3" vertical off of it is dry then it can be used horizontally but those two elbows that offset and the horizontal bit between them is not legal either.
  11. asktom

    asktom Member

    Messages:
    589
    Location:
    Victor, MT
    Sorry if it sounds like I am piling on, but the developed length of the closet bend to the vent (measuring from the floor, along the center of the 1/4 bend to the edge of the vent) should not be over 6 feet (using UPC, I don't know what code you are under - UPC is more stringent than many others). Also, the 3" cleanout can be after the vent, which would get you away from the foundation - although as HJ implied, crawling under the house to unscrew the plug of a clogged up drain is not a popular job.
  12. djn602

    djn602 New Member

    Messages:
    9
    Location:
    MO USA
    Thank you all for the feedback. I am sorry that I am a boob, I thought I had a better understanding but I do not, especially in terms of venting.

    The toilet is now vented via the 2 inch lav run (that first wye on the left) which go up the wall and connects in the attic to that 3 inch dry vent stack on the right. I am in rural MO and have no adopted code to adhere to nor inspectors to help me. The next town over is using ICC so that is what I am attempting to go off of.

    I believe I misunderstood fixture arms, they deal in a horizontal distance once you turn to vertical then all bets are off, yes? The distance from the trap weir and the top of the vent opening are restricted.

    So here is my new plan, gut what I have. From left to right: toilet into 3 inch with no clean out behind it, keep the next wye roughly where it is and have the 2 inch to the lav vented as I already do, jog the 3 inch over with two 45s to line it up with the 3 inch vent stack, wye as shown for the shower (no vent as the fixture arm with be 24 inches??), combi (in the right direction) that will be completely in line with the 3 inch dry vent stack so no jog with elbows and such. Does this sound OK? Modifications?
    Last edited: Nov 4, 2013
  13. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,281
    Location:
    Land of Cheese
    You cannot cut in a wye for the shower without venting it seperately. I would look at using a sanitary tee with a side inlet on the stack, bringing the shower into the side inlet. Be observant of the height needed to maintain proper pitch.
  14. djn602

    djn602 New Member

    Messages:
    9
    Location:
    MO USA
    OK. I will move the shower wye down stream of the 3 inch vent combi so it will pass under the wall and that will allow me to vent it into that 3 inch dry vent stack. Thanks!
    Last edited: Nov 5, 2013
  15. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,267
    Location:
    Cave Creek, Arizona
    Just because the toilet is vented by the lavatory, does NOT protect the shower from the toilet flowing past it. The shower STILL needs its own vent, UNLESS, you were to connect it to the lavatory drain BEFORE it connects to the 3" pipe. You are trying to interpret the code requirements to fit your needs.
  16. djn602

    djn602 New Member

    Messages:
    9
    Location:
    MO USA
    hj thank you for the honest feedback and info. I will admit my understanding was quite flawed but I think I have it now. I have learned the position of the toilet on the run really dictates what you can and cannot do in regards to wet venting and where other fixtures may tie in.
  17. hboogz

    hboogz Member

    Messages:
    42
    Location:
    New York
    djn -- if you get the chance to post pics of what the finished/accepted layout looks like that would be great.
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