Wet Vent from shower allowed for toilet?

[TL_]

Hi,

I am building in a bathroom in my basement and modifying the plumbing so that a toilet, sink and shower all drain into the same 3"line. The sink is all 1-1/2", the shower has a 2" line, the vent is all 2" and the toilet is 3".

I think the sink drain and venting is probably more than adequate but the venting for the shower and toilet need to be revised. As it is set up now the toilet and shower share the same drain down stream but the toilet drain passes by the shower before reaching the vent which will likely siphon the shower.

Question is can I cap the existing shower leg and use a 2x2x2 WYE off of the existing 2" vent to connect the shower drain and will this venting set up also be suitable for the toilet/ to code?

Thanks,

.

 

[TL_]

I am working in the city of Longmont who has adopted the 2012 IPC. Am I going about this wrong or will this set up work? Any feedback would be much appreciated.

Thanks,

Travis

 

[Sponsor]

 

[Terry]

Normally you would run the shower from the lav drain, the lav being 2"
That would vent the entire bathroom. How you have it now, the toilet goes by the shower drain without it being vented.

 

[Hammerlane]

Wouldn't his vent takeoff need to be somewhere in the red portion of his proposed diagram?

 

[Cacher_Chick]

Hopefully there is something untold, as a drain under concrete can be no smaller than 2", and the existing 2" line cannot be used as a vent unless it is being washed down by the lavatory.

 

[Terry]

Wouldn't his vent takeoff need to be somewhere in the red portion of his proposed diagram?

Yes, the red portion would work.

 

[TL_]

Yes, the red portion would work.

Venting out of the pipe marked in red doesn't seem to work for the layout I am trying to go for as there will not be a wall to pipe up. The bathroom is going to be very small so any piping will need to make it to a wall to be vented. (See attached mock up)

Everything in the picture is relatively close together as the room is roughly 6x6. Is there an issue using the existing 2" vent under the slab for the toilet and the shower? The 2" pipe coming out from the 3" pipe and extending to the wall looks to have been originally installed with venting the toilet in mind?

Thanks for the feed back.

 

[Terry]

You are allowed 42" on the 1.5" trap arm in the wall.
The 2" can wye off for the shower trap, continue to the wall, with 2".
Or since this is then end of the line, you may want to use 3" with a 3" cleanout in the lav cabinet.
The trap arm for the shower can be 60" long.

This shows the shower being wet vented by the lav.

 

[ChuckGM]

You are allowed 42" on the 1.5" trap arm in the wall.
The 2" can wye off for the shower trap, continue to the wall, with 2".
Or since this is then end of the line, you may want to use 3" with a 3" cleanout in the lav cabinet.
The trap arm for the shower can be 60" long.

This shows the shower being wet vented by the lav.

Hello! - Hope some is still around that can answer a question about this old thread! This photo fits for my plan. (Ignore the 1/2 wall tho and my toilet is 4" line) (I'm just a homeowner trying to do it "right" - not a professional)... Two questions. Could the one vent run be behind the shower rather than at the sink? and would it be even "better" to have a vent at sink AND shower? Thanks!!

 

[ChuckGM]

If this configuration were vented at the shower rather than the sink would it still be legal? - and would both be "better?" --- and.... What if it was just all vented with 2" behind the toilet? Would that work too? (not a professional - just a homeowner trying to get it right) Thanks

 

[Reach4]

If this configuration were vented at the shower rather than the sink would it still be legal?

Yes. I am not sure what MN code says, but if you run the shower trap arm to the wall to meet the vertical vent, everybody accepts that.

- and would both be "better?"

I am not sure what you are asking. Also, better can be different things to different people. If you are asking if having a redundant vent, then some would say that is wasteful of money and effort. If you are asking if a redundant vent might make something function better, maybe in the case of some fault, I am thinking it wouldn't hurt. I am not a plumber.

What is right is a function of your plumbing code. http://www.dli.mn.gov/business/plumbing-contractors/2015-minnesota-plumbing-code The Minn plumbing code is very similar to UPC.

The 2015 Minnesota Plumbing Code, Chapter 4714, took effect Jan. 23, 2016. The code incorporates by reference the 2012 edition of the Uniform Plumbing Code with Minnesota amendments​

 

[ChuckGM]

Yes. I am not sure what MN code says, but if you run the shower trap arm to the wall to meet the vertical vent, everybody accepts that.


I am not sure what you are asking. Also, better can be different things to different people. If you are asking if having a redundant vent, then some would say that is wasteful of money and effort. If you are asking if a redundant vent might make something function better, maybe in the case of some fault, I am thinking it wouldn't hurt. I am not a plumber.

What is right is a function of your plumbing code. http://www.dli.mn.gov/business/plumbing-contractors/2015-minnesota-plumbing-code The Minn plumbing code is very similar to UPC.

The 2015 Minnesota Plumbing Code, Chapter 4714, took effect Jan. 23, 2016. The code incorporates by reference the 2012 edition of the Uniform Plumbing Code with Minnesota amendments​

Thank you... quick follow up: When people refer to "trap arm" I can "see" what they mean - like your forum icon, basically - right? -- but there's no problem using a two-inch regular "trap" under a shower - right? AND.... to vent the shower, I can just run a vent off the line leading up to that trap just a foot or so before it - right?
Thanks!

 

[Reach4]

When people refer to "trap arm" I can "see" what they mean - like your forum icon, basically - right?

The trap arm is the horizontal line between the output of the U of a trap until the vent. That could include a trip through a horizontal bend, or it could be a straight shot.

Horizontal in drain plumbing means slightly sloped downstream -- typically at 1/4 inch per foot (2%). After being vented, the slope can get steeper.

Toilets are special in that their trap is in the toilet, and they do not have a trap arm. The slopes can be steep. In UPC, for wet venting, the toilet is usually required to be the last thing in line for wet venting.

 

[ChuckGM]

Thank you.