Horizontal Wet Vent Questions

[Titan2015]

We are in the process of remodeling the bathroom in our ranch-style home, and the time has come to address the plumbing. The previous setup used a horizontal wet vent to serve the bathroom group (single sink vanity, bathtub, and toilet). I am hoping that we can continue to use this same vent set up while replacing the poorly done plumbing, but I am not sure that the vent is done properly. I have attached pictures of the current plumbing, and a diagram of what we would like to do. I can provide additional details if needed. Thanks for the help!

 

[Terry]

That group gets a 2" vent.
Changes of direction on the horizontal are wyes and long turn 90's.
Going from vertical to horizontal, long turn 90.

I see some very wrong fittings being used there. Also, too many fittings and changes of direction.
You drawing, basic as it is is heading in the right direction assuming the fittings mentioned above are changed.

 

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[Titan2015]

Terry,

Thanks for the quick reply. I was concerned that the 1 1/2" vent would be too small for the group. Unfortunately, I'm not sure that a 2" vent is feasible in this wall due to the location of a floor joist directly below it. I have attached a photo showing the 1 1/2" from above and below the floor for your reference. A 2" pipe would require notching the floor joist.

Would the other drains need to be vented, and if so, would something like the updated paint drawing work?

 

[Terry]

The lavs wet vent the shower and the toilet. The toilet is the last one on the downhill side, so it's good there.

 

[Titan2015]

Right. Sorry, I didn't state my question clearly. I am asking for an alternative if I don't want to replace the existing 1 1/2" vent with 2" due to the floor joist. Would we need to vent the shower and toilet as I illustrated?

 

[clix]

Not a plumber, so feel free to ignore.

It looks like you have enough room for a 2" if that's a 1.5" there now, I think code requires a minimum of 2" for a wet vent (Under the UPC it's in 908.2.3, not sure what's used where you are.) Just curious, are you looking to reroute things like the red lines in the attached (this is a top down view)?

Is there a distance limitation on horizontal wet venting that might come into play for the shower?

 

[Titan2015]

Not a plumber, so feel free to ignore.

It looks like you have enough room for a 2" if that's a 1.5" there now, I think code requires a minimum of 2" for a wet vent (Under the UPC it's in 908.2.3, not sure what's used where you are.) Just curious, are you looking to reroute things like the red lines in the attached (this is a top down view)?

Is there a distance limitation on horizontal wet venting that might come into play for the shower?

Yes, that is an accurate representation of what I am looking to do.

I believe I have 5' max trap arm distance based on this reference

http://inspectapedia.com/plumbing/1623s.jpg

 

[Titan2015]

Double checked when I got home, There is no way to fit a 2" pipe without notching the floor joist.

For the shower, I am over the 5' trap arm length, measured right at 6'.

Does the trap need to be located directory beneath the drain opening? Also, what is the maximum length from the drain opening to the trap?