location of new bathroom vent

[pshome]

Converting an office space to a master bath and want to make sure I get my venting layout right before install and inspection. Room is pretty basic. Toilet and shower on one wall and a double vanity on the opposite wall. The house main drain stack is on the front of the house, about 25’ away from this bathroom which is on the back of the house. For the new bath I will run 3” drain pitched to main stack (horizontal branch or at least what I’m calling the horizontal branch). Toilet, shower with trap (2”), and vanity (1 ½ to 2) will be connected horizontal run via wyes. Question – where to vent and how many vents. The vanities will be vented via studor vents due to location on a limestone wall and distance from any other framed wall. I was thinking I could vent the toilet and shower together at location #1 via a 2” vent that ran through the wall and through the roof (shower would be wet vented, correct?). My question – can this be done or is it better to vent at location #2, downstream of both the toilet and shower. Alternatively, I could move the 3” drain north of the shower wall and vent the toilet and shower individually off their branch pipes (location #3 or #4). What’s the correct way and/or best and/or easiest way to do this while remaining in code and not causing any gurgling noises.

[nukeman]

Run the 2" vanity drain and connect to the 2" shower (after the shower trap) then connect from there into the 3" line. This will wet vent the entire bathroom. In your current drawing, the shower is not vented.

A real vent (thru the roof) would be better, but I understand the limitations with the vanity placement. Is it possible to flip positions of the vanity with the shower and/or toilet? That may allow you to run a real vent. Otherwise, the AAV should be okay assuming they are allowed in your area (some states don't allow them, but they are still sold in the stores).

[pshome]

Nukeman, I can and want to vent through the roof, I just don't know the location of where I should place it. The vent will be a 2" and run up through the wall and through the roof. Should I place the vent pipeBetween the toilet and shower or downstream of both the toilet and shower?

[Terry]

You will need a vent between the shower trap and where it enters the main line.

[nukeman]

As Terry says, the vent goes on the shower after the trap (but before the 3" line). If that 3" line could be moved up in the pic (instead of directly under the wall), after the shower trap (moving north), the vent would be taken off vertically at the wall location and the the line would continue to the 3" line (connect with a combo or wye). The thing to remember is that vents are taken off vertically (after the trap) before connecting to a line serving other fixtures (a vent on the main line doesn't work as a vent).

When I asked about moving things, it could be easier to run the plumbing with the vanity on this wall that you show and wet vent everything that way.

[pshome]

Okay, I think I got it.
Re TL - vent after shower trap & before main line (location #4). Does the toilet need anything additional?
Re nukeman - so you're saying skip the studors and wet vent through the shower vent. I like that idea, but I think the distance is going to push code (close or over 6 ft). I'll measure and / or see if I can route via a shorter distance.
Thanks

[nukeman]

I am saying that in the current layout, you have two options:

1. connect the lav line after the shower trap and wet vent through the lav (studor vent)
2. have a separate dry vent for the shower (connect after shower trap, but before the 3"). The lavs will still be vented through the studor

If you could move the lav to this wall where you show the shower/toilet, you could wet vent everything through the lav(s) and use a dry vent above the lavs (this eliminates the studor vents). I would try to do something like this in order to eliminate the studors, but if that layout doesn't work, then keeping the studors if fine (if they are allowed in your area).

[pshome]

Option #2 by Nukeman will be the way I go. Thanks guys.