how to vent a toilet...

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by coach606, Jun 10, 2006.

  1. coach606

    coach606 New Member

    Messages:
    144
    Location:
    Illinois
    Can anyone provide a picture or typical diagram? I'll need to make a long sweeping 90 degree turn, then a straight vertical drop before connecting to a horizontal drain line with a t/y combo.

    I'll need to connect two sink fixtures and a tub drain to this line. I'm thinking I can use two AAV's for the sinks, then connect the tub drain (it's a claw foot in the middle of the room) to the vent line behind the toilet.

    What I really can't envision is how the toilet drain has a vent on it unless the vent line comes from the piping that I drop down vertically through the wall on the floor below it. It doesn't work like a sink where you have a trap and then can put a T fitting and send the pipe up horizontally to become a vent. The toilet isn't working the same way so I'm having trouble understanding it.

    Thanks.
  2. It would probably be best for you to post before pictures of your proposed bathroom to give better description/drawings to fit your needs.


    Most times I install piping for a toilet with a turn up for a vent immediately in the wall behind the toilet. From there I turn the piping whichever way it needs to go thereafter.


    From there you can put wyes in the stack under the toilet to catch the other fixtures, just as long as you vent them individually. Otherwise you'll suck the traps dry when you flush the toilet.
  3. tbplumbloco

    tbplumbloco New Member

    Messages:
    60
    Location:
    Ohio
    toilet venting

    A lot depends on your lay-out of the fixtures,using the wet vent method ,you can assuming the long sweep 90 is 3" for the closet bend install a 3"x1.5"wye up to 10' down-stream of the 3"90.The 3x1.5wye takes off from the 3' horizontial in 1.5"piping also horizontally then vertically thru the floor (wall)and then installing 1.5" cross w/co installed above the cross.The 1.5"cross should be roughed in at about 18" off the finished floor depending on the type of sinks you are installing.The 1.5"horizontial pipe connected to the cross can be up to 5' in length as the distance from trap to vent for the sinks.Now the vertical 1.5"pipe coming out of the cross is becoming the the vent and should be connected to the existing vent above the flood level of the highest fixture or thru the roof.The bath tub can also be included in this wet vent method by installing a3"x2"wye down-stream of 3"x1.5"wye tight, then run 2"pipe horizontially up to 6'to the 1.5"trap of bath tub w/quarter inch per foot fall.I hope this helps,this according to the IPC 2003
  4. daveydo

    daveydo New Member

    Messages:
    36
  5. vaplumber

    vaplumber Guest

    Stay away from 90's if you can. Use two 45's if possible, as a gradual sweep is more resistant to clogging. 90's are fine on vent line, as nothing ever enters these besides air, but check code beforehand
  6. coach606

    coach606 New Member

    Messages:
    144
    Location:
    Illinois
    plans for the project...

    I'm working on some plans. My wife is also going into labor so I may not get back here for a bit. But here are some of the unique challenges the project poses:

    1) The floor joists - They run "lengthwise" in the house blueprint in the proposed bathroom. Then where a wall will be framed they run the "width" of the house. So their going in opposite directions. The framed wall is above a wall downstairs. I'm going to send the plumbing down that wall. So I'll need to seat the toilet and send the drain pipe inside the joist cavity. It's basically like turning it left if you're standing in front of the toilet.

    2) Floor joist notching. I have to get into that wall and so I have to get it through the floor joist where it changes direction. I'm not sure about how to notch or drill a floor joist for a 3" pipe.

    3) There will be two sinks. I'm going to run the drains to the 3" pipe once it goes vertical in the wall.

    4) There will be a main vent pipe of 3" through the roof. But how I vent the toilet is a bit of a puzzle. I guess I can run a 2" pipe over the doorway to the wall next to the toilet. But I'll need to use a sanitary T fitting somewhere in the wall right before it takes the vertical drop.

    5) The tub. It'll be a cast iron (or similar, slightly lighter version) pedestal tub with a center drain. I'll run the drain line to the sink lines and then send it down to the 3" pipe together. DOES THE VENT LINE NEED TO BE BEHIND THE TUB drain? or can it just be about five feet away where it hooks up with the sink drain lines?

    That's the plan. Any comments?

    My main concern is how to notch and drill the floor joists and where to put cleanouts.
  7. daveydo

    daveydo New Member

    Messages:
    36
    A pic of the proposed site of the joist holes would help. Anyway consider this, drilling or notching a floor joist will of course weaken it. Having said that, a drilled hole in the center is best. What notching will do is create a stress raiser at the inside corners created by the notch, thus significantly weakening the joist . Such a large hole is fine in 1 or a couple of joists but note that the greater distance between the holed joists the better. Further, the closer the hole is to a bearing point the better and the deeper the joist the better.

    I am only going to this depth of explanation because I've seen some hacked up floor systems in both new construction and renos for plumbing rough-ins. I hope this will be of some help.
  8. daveydo

    daveydo New Member

    Messages:
    36
    Justread the last line of your last post again. How many joists are you considering to alter?
  9. coach606

    coach606 New Member

    Messages:
    144
    Location:
    Illinois
    Just one joist...

    Thanks for the advice. I really appreciate it.

    It'll be just one joist for the 3" pipe, the transition from the joist that run s lengthwise to the joist that runs the width of the house. Then it'll head vertically straight down a wall.

    The 2" drain pipe from the sink and the tub will also have to go through that joist, then link up with the 3" pipe.

    The odd thing is that the floor joists are going to be sistered up to 2 x 10s. They're less now. So they'll be laying a sister joint on the side.

    Does it matter where the vent pipes connect to the individual fixture drains? I figured I'd run a vent pipe up from behind each sink, and then one up from where the tub drain will connect to the sinks' 2" drain pipe, and then one right before the 3" toilet pipe goes vertical. That one's hard to picture.

    The tub and the toilet vent will both be downstream of the fixture. Is that okay?

    I'll work on a drawing once this kid is born.

    Thanks.
  10. Lakee911

    Lakee911 I&C Engineer (mostly WWTP)

    Messages:
    1,328
    Location:
    Columbus, OH
    That's one determined DIYer! "I said hold on, Honey! I'm almost done with this message....Ya, hold on. C'mon, he waited 9 months, what's 10min?"

    :)

    One joist is ok. Make sure your hole is centered in the new 2x10, if possible. For added strength, glue and nail the heck out of this joist for added strength. I'm not sure if they make a 3.5in/90mm hole saw, but thats' your best route. Else you could use a jig saw.

    You want your vent pipes as close to the fixtures as possible. I think your locations generally sound fine. How far downstream are we talking?

    Jason
  11. it's all about distance.

    Venting appropriate to a toilet has to be within X number of feet. How big is your pipe? (3" or 4"). What distance is the nearest connection to anything at all? How much slope does your toilet pipe have? (I mean, once it turns horizontal, under the floor, going to its first connection).

    -david
  12. coach606

    coach606 New Member

    Messages:
    144
    Location:
    Illinois
    it's a girl...

    I now have a second daughter... and a moment here to continue planning the upstairs plumbing so that we can all live in our house together!

    I was planning on having the lav connect to 3" pipe. I'll check my plumbing code book for information on how far away the vent pipe can be. I'm in Illinois, in case anyone knows. Is there a general rule on this?

    Thanks.
  13. Lakee911

    Lakee911 I&C Engineer (mostly WWTP)

    Messages:
    1,328
    Location:
    Columbus, OH
    Congratz! Ok, back to plumbing.... :p

    Jason
  14. coach606

    coach606 New Member

    Messages:
    144
    Location:
    Illinois
    Some rough sketches of my layout...

    I've attached two photos and would appreciate any advice on them. I was unable to fully draw everything I wanted - like the vent from the sink coming around to a 3" vent pipe near the toilet.

    Here's what I'm struggling with:

    1) Where to locate the 3" vent through the roof. This is an unfinished attic space so the ceiling dimensions slope. Since the vents must be above the highest fixture it might need to be located towards the center of the room.

    2) Where do I vent the toilet? If you are standing in front of the toilet, the drain for the lav turns left and then must go through a floor joist and straight down a vertical wall. I drew a plan using two 45's and a bit of straight pipe, but that might be wishful thinking if I actually want it to go down the wall without widening it or building a little soffit.

    I just can't tell right now if I'll be able to get a vent (especially a 3" one) to the lav dwv before it turns down the wall. I have a few ideas, so I'll make a sketch.

    3) If I take out the 3" vent pipe I now have coming from the lav drain before it turns down the wall, can I put a vent for the toilet in that vertical wall with a T/Y combo? It wouldn't be very far from the toilet, but it would be below the toilet. I'll sketch it.

    All advice greatly appreciated! Sorry if the pictures are bad. I had a heck of a time getting my scanner to scan within all the ranges the site wants.

    Attached Files:

    Last edited: Jun 16, 2006
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