Can I use a double wye in vertical position?

[Ryanwake]

I am currently removing the old cast iron in my basement and replacing it with PVC. The 4" sewer that runs through my basement wall is located directly below (about 24" from the wall) the 3" main soil stack. Can I use a 3" double wye to pick up the kitchen to the right and the bathroom to the left? the middle of the wye would continue on through the roof. All fixtures traps are within 24"-58" of the main stack going through the roof. Plan to use 2" SCH40 for shower and kitchen sink drain which are the farthest at 50" and 58" respectively. All drains would be located physically higher than where the toilet enters the stack on its' way out the basement wall. Its a small 900sqft house. I hear inspectors don't like to see double wyes in the horizontal position but can't really find any concrete info on the vertical position. I am located in Michigan. Thanks in advance!

 

[hj]

The distance to the fixture traps is immaterial, becausethat central pipe is not, or at least should not be, the vent for them. If that "double Y" IS the vent for them then you CANNOT use it.

 

[Sponsor]

 

[Ryanwake]

Here is what I had have mocked up...

The distance to the fixture traps is immaterial, becausethat central pipe is not, or at least should not be, the vent for them. If that "double Y" IS the vent for them then you CANNOT use it.

 

[Terry]

The only fixture vented there is the toilet.
The lav, shower and kitchen will need their own vents.

 

[Ryanwake]

The only fixture vented there is the toilet.
The lav, shower and kitchen will need their own vents.

Even if they are less than 60" away for the 2" PVC drains (and the 1.5" is only about 36" away) from that main 3" going through the roof? All the sinks, toilets etc are located physically within about a 55" radius of that main soil stack. I am having trouble getting all of that to fit into such a little space in the basement and trying to avoid having to demo a wall, remove the kitchen cabinets and potentially the tub. Should I use sanitary "T's" to tie back into the stack from each of the drains there in the basement? I've attached an image as to what I may have assumed incorrectly... Thankfully nothing is glued yet

 

[Terry]

The venting is above the pipe, not below like the way yours is plumbed.
You can't cover your head by putting on shoes.

 

[hj]

The way you have things arranged, they could be 6 INCHES from the 3" and would still need their own vents. The 60" measurement is for a special case and even then it might only be 42 or 48".

 

[Ryanwake]

OK sorry I just got this last post from you after I reworked the setup... Here is what I came up with before your reply... Am I getting any warmer?

 

[Terry]

That is even worse.

Before the toilet was vented, and now you've gone up and down with the toilet vent.
The other fixtures are still not vented off of that. They will need their own vents, vents which can tie together at 42" "above" the floor, not below.

 

[Ryanwake]

The way you have things arranged, they could be 6 INCHES from the 3" and would still need their own vents. The 60" measurement is for a special case and even then it might only be 42 or 48".

 

[Ryanwake]

Ok. So there's no way for any vent to tie in down in the basement off of that 3" stack going through the roof? I don't really have access to inside the walls... The shower drain would be impossible (I think) because it has no where to go "up" to 42" above the floor.

 

[Terry]

Does the lav now have a vent above the trap arm? (if coming from the wall behind)
Or are you using an S trap from the floor?

If the trap arm for the lav is coming from the wall, it's most likley vented in the wall.
The same could be true for the kitchen.

 

[Ryanwake]

Does the lav now have a vent above the trap arm? (if coming from the wall behind)
Or are you using an S trap from the floor?

If the trap arm for the lav is coming from the wall, it's most likley vented in the wall.
The same could be true for the kitchen.

Both the lav and the kitchen sink drains came through the floor about 6-8" or so from the wall. There is/was no possible way they were vented in the wall. The house was built in the early 60's and is in a subdivision of like-houses... Floor plans are all very very similar except flip-flopped layouts etc. I assume all houses were plumbed like this when they were built. So there is no way that a vent can be located at downstream from the trap even if it is physically higher than the drain? Here is the layout of the bathroom and kitchen. Basically everything came through the floor and dumped into the cast iron via it's own branch (for lack of a better term) and the drawing I have is not to scale. The tub drain from sewer pipe coming in the house is about 55" from where the trap would be. The kitchen sink is about 48" and so is the lav sink. The toilet is about 28" away.

 

[Ryanwake]

That is even worse.

Before the toilet was vented, and now you've gone up and down with the toilet vent.
The other fixtures are still not vented off of that. They will need their own vents, vents which can tie together at 42" "above" the floor, not below.

Ok so I'm now running (2) 3" pipes up inside the wall in this mockup. The original runs up straight thru the roof. If I tie in the one middle portion of the double wye (closer to foundation) up inside the wall (~48" off the floor) to the main soil stack with a sanitary "t" (converted to 2") would that work? i am going to cut out my backsplash area between cabinets and work from inside there. So much appreciated.