run drain paste toilet to Laundry sink and wMB. Toilet should be on its own wye 45 on the way to toilet run a 3 by 2 wye to the shower. Then run a 1.5 inch drain to the lav off the shower drain with vent. 8 foot max distant from the shower trap.
Tie the bar into your waste stack with its own vent.
Both of these vents can tie together 42 inches above the floor and run it into the attic to penetrate the roof our run overhead to laundry and tie them into that.

Washer and LT cannot be used to vent a toilet. Only Bathroom group fixtures can wet vent a toilet. Defined as Toilet lav sh or Tub bidet and floor drain in the bathroom. The bar will need it own run to the main drain with a vent. Problem number 2 You will need to run 3 inch to the WMB LT 3 inch to wmb 3 by 2 tee with 2 inch to wm standpipe then 1.5 inch above tee to LT with vent. 406.3 is why. Your inspector may not enforce this.

I tried to redo your drawing but could not save it.

WMB=stand pipe
wc=toilet
LT =Laundry sink

Vent from lav out the roof if greater then 40 foot in total length will need to be run in 2 inch and the lav drain also.

floor drain would tie into the 3 inch drain to the washer no vent because it is a combination drain and vent. You will also need a trap primer on that floor drain or something keeping the trap wet.

 

@Ghostmaker

Here's a sketch of what I think you are saying.

Orange is existing 3" (all other colors are proposed)
Purple 3"
Green 2"
Blue 1.5"

whoops. Assume the floor drain has a trap... Doh!

Assuming I drew your description correctly, I see some potential concerns.
1) The lav drain makes a full 180 or worse if it is used to wet vent the shower, and WC.
2) I thought the WMB going straight through the WC wye might have been a bad idea? But that is negated by the lav wet venting the bathroom?
3) Can I tie 1.5" vents into a vent that is 2" all the way to the roof? I thought I might not be able to reduce/expand on pipe, certainly on drains, but also vents? I have room to go 2" on all vents.
4) Honestly don't think I'm up for the floor drain. I'd have to grade the floor, keep it wet, and there is an open sump pit 3 ft away from that location. So would I just chop it off and change what looks like a combo wye to a LT 90?

Either way, this example was useful. I think I'll draft up another idea of how I think I could address these concerns, and still be good, code-wise/function-wise.

 

This is my best attempt at an improvement. Same sizing scheme
Orange existing waste 3"
Purple 3"
Green 2"
Blue 1.5"

The hangup I see is whether I have enough clearance with slopes for the shower drain to drop twice. I assume I can't run a horizontal dry vent for the shower. And that's why you say to wet vent the whole bathroom off of the lav? The main drain is about 1' 6" below the top of the slab, according to a ridgid locator I rented a while back.

 

Your toilet is still not vented to code. Your shower wye needs to drain just downstream of your toilet 90. You show it as being vented and that is fine. in order toilet, wye to shower then main drain going past toilet to washer and utility sink, floor drain trap.

Move your vent between the lav and the bar sink and that would make a circuit vent.

On your shower just place a tee on its back looking vertical for the vent. No need to jump up.

 

I know this sketch has poor perspective. But, move the shower drain connection to between the toilet drop and the WMB/LT drop. Make the lav/bar sinks on a circuit vent. (didn't have room to put the trap on the WMB in the drawing, but it'll be there). This look about right, assuming I use the correct fittings? I might have to "wrap" the shower drain to the wall with a 45 for the vent to pick it up.

I'm pretty sure I remember what fittings to put where. I'll try and mock it up and see what I come up with.

If it is good code wise, does it seem good from a functional perspective?

 

I mocked it up. I think this will work. It is a relief that the center of the WC combo wye is 12" from the front face of the LT/WMB stack, so it fits the toilet rough in.

Not pictured: The 3" section headed towards the building drain ties in with a 3" combo wye.

Lazy mockup hacks: Not a proper p-trap on the WMB, shower p-trap left out.
The shower vent will likely be moved closer to the 45, the trap arm for the WMB will be closer to the shower vent.

One modification, the shower vent takeoff is a combo wye rotated 45 degrees, to help if the cleanout on the shower vent needs to be used.

Also, depending on heights, I might swap the conical reducer for an insert/ring style for the LT fixture tee.

Look good?

 

Not legal.
We are trying to vent the toilet. You cannot have the washer and utility drain through the toilet. Move your piping to the left dump your 3 inch long sweep wye for the toilet. Toilet 90 then three by 2 wye 2 inch to shower with vertical vent and trap under the shower. then 3 inch wye branch attaching to 3 by 2 wye. Front of 3 inch wye to your laundry room. Nothing from that laundry room can flow through the toilet.

 

This is legal

 

Also get rid of the clean outs. Not required unless your inspector is a tard. The Toilet is a cleanout.

 

Thanks for the sketch! I assume that 3" branch after the WMB stack is for a floor drain? I think I ruled out a floor drain for now.

I see what you mean by killing the toilet vent.

What about something like this? I think it follows the same idea, and works better with spacing (I'm low on spare fittings)
If not, I can revisit your sketch.

Somehow I thought the cleanouts would be a good idea, I'm happy to get rid of them though.

I know 45+ deg is considered vertical for vents, is it worth the effort to make the shower vent perfectly vertical, or can I try to 45+ up to the wall cavity?

 

Now you got it. Dump the clean outs. Also get the right wye's. Use a sanitary tee on its back for shower vent. Cleaner install. Take the unused stuff back to home depot for refund.

I assume that 3" branch after the WMB stack is for a floor drain? My attempt to remind you of the 3 inch requirement.
I know 45+ deg is considered vertical for vents, is it worth the effort to make the shower vent perfectly vertical, or can I try to 45+ up to the wall cavity? As long as the vent is at a 45 degree pitch until it turns vertical you're ok.
Good luck. P.S. make sure you hold what you prime and glue for a while so your joint doesn't pop out.Also have a small level handy for pitch checks. Support pipe in horizontal 4 foot intervals.

 

Awesome, thanks!

Any practical benefit in moving the 3" wye (where the WMB drain connects to the WC drain) further down? (away from the WC bend and 3x2x3 wye)

My last picture had the shower drain going 90, then 45 (to get the completely vertical vent in the wall). Is it worth the tradeoff to go with a partial 45 degree "vertical" vent if I can reduce the number of bends in the shower drain? Ultimately, I think when I mock it up, I wont have enough room for the WMB to pull that off, but just in case...

 

Awesome, thanks!

Any practical benefit in moving the 3" wye (where the WMB drain connects to the WC drain) further down? (away from the WC bend and 3x2x3 wye)

My last picture had the shower drain going 90, then 45 (to get the completely vertical vent in the wall). Is it worth the tradeoff to go with a partial 45 degree "vertical" vent if I can reduce the number of bends in the shower drain? Ultimately, I think when I mock it up, I wont have enough room for the WMB to pull that off, but just in case...
[/QUOTE

Any practical benefit in moving the 3" wye (where the WMB drain connects to the WC drain) further down? (away from the WC bend and 3x2x3 wye) Any pressure disruption caused by the washer going off will pull air from the shower vent.
On your second question Im not worried about the bends.
Hard to tell your pipe size on the washer sanitary tee but it should be a 3 by 2 tee with 2 inch over to the washer box.

 

That's good we should take another look at your lav sink bar your local inspector may not like the circuit vent.

 

Here's what I've got for the circuit vent. Seems like there is some room to drop a drain/vent into the main drain for the lav. The bar sink wouldn't clear the 10x diameter rule (if I am recalling that one correctly). I'd like to keep the wall cavity clear above the lav for a recessed medicine cabinet. ~30-36" wide.

 

Also, it will help if you tell me what is on the drain above due to load limitations of 2 inch purple stack. You have 3 dfu new going into it. Keep in mind those vents cannot tie back into the purple stack until your 42 inches above the next floor above. As long as there is nothing draining into it at that point.

914.4 Relief vent. A relief vent shall be provided for circuit-vented horizontal branches receiving the discharge of four or more water closets and connecting to a drainage stack that receives the discharge of soil or waste from upper horizontal branches.

Your inspector may want a second vent between the Bar sink and purple stack. If he is not reading the above correctly.
P.S. Do Not use those all rubber couplings for your tie in. Use the correct pro flex band or mission brand coupling. Those all rubber garbage do not hold pipe alignment. They also are not legal above ground.

 

The purple stack is 3" to the roof. It goes horizontal a little, then vertical to the roof as 3". It receives:
One bathroom group on the floor above, the 3" stack vents that group to the roof, wet vent through lav. Water closet and bathtub.
There is another bathroom on the upper floor that uses that stack as a drain, but those (shower/WC/Lav) are also independently vented to the roof. *another wet vent via Lav.
Kitchen sink drain ties in after the two bathroom groups, and is independently vented to the roof.


The 2" vents I show in this drawing will all be connected to a separate 2" vent to the roof (that I roughed in when I had walls opened up for a bathroom remodel), independent of the 3" stack/vent, I do not plan on tying back into the purple stack for venting, except for using it for the bar/lav drains, if possible.

 

So it is ok to put the lav and bar sink together draining into the stack, and vented with the rest of the bathroom/laundry on the 2” to the roof?

 

I would pass it.

 

** Edit: Considered taking a shortcut... Chopped out the abandoned pipe. Feels better.