Wet venting vs individual venting

[TEstsolarus]

This is probably obvious to folks on this forum, but haven't been able to figure it out despite looking through. In most wet venting configurations, the toilet appears to be at the end.

Trying to figure out how to vent a bathroom (shower, toilet, sink), all draining through the toilet drain in the middle with only a single vent. SHOWER--->TOILET <--- SINK.

Is this possible, or do the additional vents (in red) need to be added? Which fixture should the single vent (green) be connected to avoid having individual vents on each fixture?

 

[hj]

I usually run the green vent from a side inlet sanitary tee for the toilet. The shower into the side inlet and the lavatory into a tee in the vent.

 

[Sponsor]

 

[Terry]

In your drawing the shower needs the vent.
The shower vents before it hits the toilet line. The lav gets vented like in the drawing.
A vertical fitting like hj mentions would also work for that.

 

[TEstsolarus]

Thank you so much Terry and HJ.

My understanding of what HJ proposed is below. Correct? I conceptually understand this approach, where basically each fixture is connected with a T to the common vent separately.

However, I was under the impression that it was possible to do this with only one vent, using a wet vent technique (second image below). I can't figure out what that would look like with the toilet in the middle, embarrassing as that is

This is wrong. The moment the trap arm is raised to the tub, it is no longer vented.
And the vent above the lav must be 2" or larger, as is the lower portion too.
Terry Love

 

[MKS]

I believe your revision to your first drawing, green and blue, would represent a dry vent arrangement.
The second drawing, maybe closer to the wet vent arrangement. Both minors are vented prior to entering the toilet line. I think.
I understand vaguely, both the sink and shower/bath tub must be vented prior to entering the main drain that the toilet is draining into.
So in the second drawing, rotate the sink left, move toilet to center and work from there. This diagram may help.
There are many considerations to do this right.

 

[Terry]

The tub can wet vent over the toilet, and the lav over that.
Trap arms for 1.5" can be 42"

The vent pulls off even or above with the trap arm, not below.
The gray drawing is wrong.

 

[MKS]

Thanks

 

[hj]

Toilet in the middle is the easiest way. The toilet goes into the tee, the shower goes into the side of the tee and the lav goes into a tee in the vent. Your drawing is NOTHING like I described.