Simple VENTING Question - Basement Tub / Wet Bar Rough-In

New user to the forum, please be gentle. : \

I took up my basement slab (lots of fun) and so I've got a clean slate. Here's the situation: there's a 4" main line running down the middle, 3' away on either side, I want to install a 2" bathtub drain and a 2" wet bar. See diagrams.

If I were to run both drains to the 4" with a double wye, would the bathtub still be vented properly? (Scenario A)

Or should I run the tub drain to the AAV and then back to the main? (Scenario B)

Or is there an even better solution?!

Thanks in advance.

You can't wet vent through anything other than bath group fixtures. The tub is too far from the vent

Bottom picture: NEITHER fixture is vented.
Upper picture; It depends on distances, but an AAV seldom vents a basement fixture properly.

Tom Sawyer said:

You can't wet vent through anything other than bath group fixtures. The tub is too far from the vent

Click to expand...

So you're saying I can't vent through that AAV because it's attached to a wet bar sink as opposed to a bathroom sink?

In regards to distance from the vent, I have been trying to read through my local plumbing code, and it states that for 2" the maximum trap arm distance is 7.8'. Am I mistaken in how I'm reading this?

hj said:

Bottom picture: NEITHER fixture is vented.
Upper picture; It depends on distances, but an AAV seldom vents a basement fixture properly.

Click to expand...

The only stack in the house is over 10' away. It's a 60 year old house and, keeping in mind my limited plumbing knowledge, I don't think I have any other options besides using AAVs (which are code-approved in my region).

I had a licensed plumber come in to help me with the design and he recommended AAVs regardless of who was doing the install.

What would you suggest as an alternative?

I am not suggesting, I am telling you that you can't wet vent through a bar sink, kitchen sink, laundry tray, washing machine etc, only bath group fixtures.

Tom Sawyer said:

I am not suggesting, I am telling you that you can't wet vent through a bar sink, kitchen sink, laundry tray, washing machine etc, only bath group fixtures.

Click to expand...

My local plumbing code does not make any mention of this restriction. Can you please elaborate?

From the code I'm working with:

"Wet vent means a soil-or-waste pipe that also serves as a vent pipe and extends from the most downstream wet-vented fixture connection to the most upstream fixture connection."

"2.5.2.1. Wet Venting
(See Appendix A.)
1) A soil-or-waste pipe may serve as a wet vent provided that
a) the hydraulic load is in accordance with Table 2.5.8.1.,
b) the number of wet-vented water closets does not exceed 2,
c) where 2 water closets are installed, they are connected at the same level by
means of a double sanitary T fitting if the vent pipe is vertical and by means
of a double Y fitting if the vent pipe is horizontal,
d) the water closets are installed downstream of all other fixtures,
e) trap arms and fixture drains connected to the wet vent do not exceed 2 inches
in size, except for connections from emergency floor drains in accordance with
Sentence 2.5.1.1.(3),
f) the total hydraulic load on the wet vent does not exceed the limits stated in
Table 2.5.8.1. when separately vented branches or fixture drains in the same
storey, having a total hydraulic load not greater than 2 fixture units, are
connected to the wet vent or a wet-vented water closet trap arm,
g) the hydraulic load of separately vented fixtures that drain into the wet
vent are not included when sizing the continuous vent that serves the wet vent,
h) where a wet vent extends through more than one storey, the total discharge
from any one storey above the first storey does not exceed 4 fixture units,
i) there is not more than one nominally horizontal offset in the wet vent, and
i) the offset does not exceed 1.2 m for pipes 2 inches or less
in size, or
ii) the offset does not exceed 2.5 m for pipes larger than 2 inches
in size,
j) the wet-vented portion is not reduced in size except for the portion that is
upstream of emergency floor drains in accordance with Sentence 2.5.1.1.(3),
and
k) the length of the wet vent is not limited."