Please teach me how to plumb this bathroom

[LilyT]

Hi there, I'm adding this bathroom on upper floor over a garage on the main level. There is a roof vent on the left. And the drain pipe will hang below the ceiling of the main level garage in a plumbing soffit next to the inside of the exterior wall.
Could you show me how to connect the bathroom fixtures to the drain line and vent?

 

[Mr_David]

use combo fittings or wyes with branch lying on the side for toilet and shower,
You come out of wall under floor joist with 90's turn 45 to joist and use a wye or parallel to joist and use a combo.
use a 3 x 2 low heel 90 for toilet , 2" for vent, bring toilt waste arm back to wall. 90 down with low heel then lurn back out of wall to main with another 90.

 

[LilyT]

Thank you, Mr. David! DWV pipe layout is really hard, I didn't realize it until now.
Thanks for sketching out the connections! I'll find out each connector you mentioned and try to construct the 3D image in my mind. May ask you more Qs later.

 

[LilyT]

I'm adding another bathroom on main floor. The drain pipe from upper floor will come down at the corner of this bathroom, then travels ~25' before going down to basement. Do you see any issue of this configuration? Do I need vent near the y-joint in the blue circle?

 

[Mr_David]

why don't you open the garage floor and put it under the slab instead of raising the floor?
You're going to have to have a minimum of 6" of fall on the drain.
You're also going to have to vent each fixture.
make you floor joist run the shortest length of room.
Got to go

 

[Mr_David]

I have been playing with this for a bit and this is what I have.

When I was lookin' up dimension of fitting I found one that I have never used and might be a bit harder to round up BUT MAYBE you can use for toilet vent.
I'll leave that for last so as not to confuse you





street low heel might be harder to find but

With the combo lying on it's side anot sure if you can use the side inlet for toilet vent.
Don't see any reason why not.
vent has to be no more than 45 degrees from vertical until it is above the flood rim.

 

[Mr_David]

the other fitting I mention

 

[LilyT]

This is very helpful! Thank you so much, David!

 

[Rossando]

As a service technician I would imply that you put a clean out for the bathroom downstairs in an accessible. Like behind the wall on the vertical pipe but not too far up maybe 12” from finished floor.