Vent Pipe Configuration

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Centuriondk

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Appleton, WI
Hello Everyone,

I'm working on a bathroom remodel and I'm hoping you guys can assist with my general lay out.

I am going to have a sink on one wall, the sink will have a vent pipe running up and connecting to my existing vent in the attic.

My other wall will have the shower and toilet. The original layout proposed by a friend who is more of a general contractor type and not specially a plumber calls for a single vent line between the toilet and the shower.

When visualizing a vent I think of it being closer to the shower/toilet. Is a vent pipe midway between each of them (approx 20" away from each drain) acceptable? Will it work? My attempt to sketch out the configuration in MS paint is attached. I'd appreciate any imput! Thanks.

Diagram.JPG
 
Allowable locations for vents varies considerably between codes. In my area, what you have drawn would be allowed. That said, I would try to move the main drain connection to a point between the toilet and the vent.
 
in my area you would have to vent them seperatly and the you could tie them together at 42'' above the floor or 6'' above the flood rim of the highest fixture.
 
The Uniform Plumbing Code would require you to vent them separately and tie them together at 42" above the floor. The vent sizes would need to be 2" for the toilet, 1.5" for the sink and 1.5" for the shower. They could all tie into a 2" to go up with. As for drains, the sink and shower should be 2". The toilet should be 3" or 4".
 
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Hi Everyone,

Thank you for your help so far. Since the first comment mentioned that it might be ok in some places I ran a copy of the drawings (after I fleshed them out some) past the inspector and he affirmed the later responses that I couldn't vent it as I was planning to.

I am however struggling with where to tie the vents in. Right now I'm dry fitting everything together, after which I will have a friend of my inlaws who is a plumber come in and look it over (the home inspector has so far been very unresponsive and unhelpful which has a me a little worried about the actual inspection) Ideally I'd like to have everything in place by then so he can make any tweaks I need.

I've attached a couple of pictures, if anyone can recommend a good place to tie the vents in I'd appreciate it!

As a side note, the fine people at home depot (who assured me they were licensed plumbers) told me to go with a 1 1/2" drain on the sink and that a vent had to be 1/2 the dimensions of the largest fixture. So in my case the 3 in toilet drain = 1 1/2" vent. In light of Joe's comments was this blatantly incorrect or something that might be different by region?

One last question, I was also told that a shower is supposed to have a standard P trap. My current shower does not but this could just be because it was built 50 years ago and has drum trap that is causing me a lot of problems and will be going out the windows once I get to that bathroom.

IMG_2720.jpg

IMG_2722.jpg
 
What you show in the pictures is not likely to be accepted by code. There is no vent available to the P trap. Also, compression joint P traps are not normally allowed in a concealed, unaccessable location. You will need a solvent weld P trap for that application.
 
Hello,

The pipes are going to be accessible from underneath via an access panel I'm going to put in the closet below it.

Regarding the vent, that's what I'm trying to find a location for but I'm not sure where to try to place it. How far along in the piping is the vent supposed to be? Directly after the P trap? (Option A) I should be able to get enough room for a T if I readjust some lengths and angels, I'm just having a little trouble conceptualizing how to run the vent for a shower. (Where as a sink is straight forward with the vent continuing upwards from the drain pipe. )
 
Ideally, you would run the piping to the P trap under a wall on the way to the P trap and turn a vent up in that wall. Do not run any part of the vent flat until you get it 6" above the rim of the shower.

To explain a little farther, the vent would need to attach in the section of piping that the longest red arrow points to in your first picture, between the 90 ell and the P trap. Obviously, that section is not under a wall as you presently have it piped, but that hopefully gives you the idea where in the piping arrangement the vent needs to be located.
 
Hello,

I just want to make sure I completely understand the suggestion. I agree it would be much simpler if I could run this up through the wall, unfortunately the wall of the closet below doesn't allow me to do it that way. (This would also prevent me from being able to access it via the future access panel in the closet).

Regarding the later statement about making sure to not run a flat vent pipe (so the water doesn't sit in it) and bringing it into the wall, would a sloped vent pipe like the attached most likely be acceptable? Lead it over to the wall on a slope and then go straight up from the wall?

IMG_2720 - Copy.jpg
 
No, the vent pipe must run vertically from it's connection to the drain pipe till it is 6" or more above the rim of the shower. That is why I mentioned routing the drain pipe underneath a wall on the way to the trap.
 
Alright I think I'm on the same page now. In that case, if I put the "T" pointing upwards (rather then to the right) and lower everything 6" so that I can run the vent pipe up 6" vertically before making an "L" and bringing it to the wall, that would be up to code? (I've attached another picture, it's a little difficult to explain in writing)

IMG_2727.jpg
 
The vent has to rise vertically to at least 6" above the rim of the shower that the P trap drains into, not just 6" above the P trap. That is why you need the drain pipe for the trap to run underneath a wall on it's way to the trap.

It is really hard to look at pictures of the piping without knowing exactly where the walls above are going to be, and come up with a schematic and fitting list. But I suspect that you will have to get rid of the heel inlet 1/4 bend that you currently are planning to attach the P trap to, replace it with a standard 1/4 bend, and use a combination wye and 1/8 bend on the upper section of horizontal 3 " pipe to attach the drain arm to. Run the drain pipe over underneath a wall, turn up with a 1/4 bend, stack a street santee on top of that to run to the P trap, and continue the vent upwards into the wall of the floor above.
 
I suggest you just get a Qualified plumber and a framing contractor to look at it..
You may need to cut away some lumber and reconfigure it to properly achieve what you have in mind.
 

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