Another Wye or Tee Question

Hello,

I am a bit confused. I am building in Idaho and have a question about connecting a toilet to vertical drain. I have attached a picture to better depict my question. Do I need to come into the vertical waste line at a 90 with a Tee? Or can I run the waste from the toilet as shown?

Thanks.

jb9 said:

Hello,

I am a bit confused. I am building in Idaho and have a question about connecting a toilet to vertical drain. I have attached a picture to better depict my question. Do I need to come into the vertical waste line at a 90 with a Tee? Or can I run the waste from the toilet as shown?

Thanks.

Click to expand...

Idaho uses International Plumbing Code (IPC).
I could be wrong, but I believe you need to vent the toilet on the horizontal arm before it takes the turn down.

To tie in to a horizontal line you use a wye (this prevents crud from splashing back up), to tie in to a vertical line you need a tee (a wye would block the air from venting).

So, at that elbow going down from the toilet's horizontal line, I would have a tee and have a vent pipe go up into the wall above the flood level of the toilet then the vent can tie in to the main stack vent with another tee. The drain for it would tie in to that vertical pipe with a tee as well.

Plumbers, if I'm wrong, please let me know.

JB9

that would be illegal, on a vertical stack,you se a tee, because, the trap arm has to be vented, and a wye cuts off this vent

HAH!

My newly learned FACTOID OF THE DAY...

I am slowly but surely understanding proper venting...

Ok, so I'm glad I wasn't wrong about the wye not being right for vertical connection.

Frodo, would the elbow he drew on the closet bend have to be less than 45 degrees? I don't want to confuse the rules, but I think 45 or greater would also cut off airflow?

So he would have to tie in to that vent stack with a tee much higher up than in the drawing, correct?

While trying to figure out layouts for pipes, I came across these:

the use of elbows is this


draining vertical to horizontal has to be a long sweep

draining horizontal can be a short sweep or long sweep to vertical

loop hole....unless structurally unable,





the long sweep minumises of the vent being cut off

Under IPC, that wye is legal on a water closet.

Convincing your inspector that it is might be another matter.

phishfood, to clarify, it might be legal if a sweep was used instead of a 90 elbow, right? I remember reading somewhere that 90s are for vents and the drains need sweeps.

Also, thanks for that info, Frodo!

Zanne said:

phishfood, to clarify, it might be legal if a sweep was used instead of a 90 elbow, right? I remember reading somewhere that 90s are for vents and the drains need sweeps.

Also, thanks for that info, Frodo!

Click to expand...

Table 706.3 is where you go to find out what fitting is to be used where. There are places where a quarter bend can be used in drainage. Short sweeps can be used in more locations, and long sweeps can be used in any orientation and any pipe size.

see the difference in codes

Thanks for the help guys!

I am attaching what I have redrawn with a couple options. I am leaning toward the option with the stacks more closely clustered. I have also drawn one with the drain stack a bit further away to give me some flexibility with the downstairs lavatory's vent.

Hopefully the new toilet vent + San Tee in both cases is correct.

jb9 said:

Thanks for the help guys!

I am attaching what I have redrawn with a couple options. I am leaning toward the option with the stacks more closely clustered. I have also drawn one with the drain stack a bit further away to give me some flexibility with the downstairs lavatory's vent.

Hopefully the new toilet vent + San Tee in both cases is correct.

Click to expand...

Does the tub have an overflow?
I'm guessing the pipe from the tub is 2"-- how long is the trap arm before it meets the vent in the one that is closer together? In order to avoid having a crown vent (which allows siphoning) you need the trap arm to be at least 4-inches long. Thanks to Frodo for that info.

I will have to defer to the professionals on the rest since I honestly don't know, but it does look fine to me.

Thanks for pointing that out Zanne. In my drawing, I have measured about 4 1/2" (from the trap weir to the outside of the vent pipe) so hopefully that should work. Again, I certainly understand my drawing is just a rendering at this point, but it's good to catch all the pitfalls and work to avoid them.

My 2.5 cents worth.

For those who didn't notice; I cut and flipped the wyes on the stackes.