Peninsula venting in level counter

[knickema]

We have our sink in the peninsula with the vent running through a half wall to the exterior wall where the vent stack is. The house was built in 2003. It is not code right now (6" above flood level of sink) because the vent is 34.5" from the floor and my current top mount sink is 37".

We want to move the half wall with plumbing out 8" and have a level countertop. We are on a concrete slab with tension cables and the waste drain is in the slab, so we cannot move the location of the kitchen sink, cannot move the waste drain, and cannot do an island loop vent (because I don't want the very expensive cost of breaking up the concrete slab). Studor vents are also not allowed.

Do I have any other options in order to have a level counter? Or am I stuck with a 2-tier counter in order to have the vent be 6" above the flood level of the sink? A plumber proposed doing a dirty arm, but I can't find much about them online, or if they are code for kitchen sinks. Everyone keeps saying island loop vent or Studor, both of which are not options for me.

I tried to attach photos, but kept getting error messages.

 

[knickema]

 

[Sponsor]

 

[knickema]

 

[knickema]

Yay, was able to load photos by posting reply. The horizontal run of 2" pipe in the picture is the current vent that runs to the exterior wall where the peninsula attaches to the wall. The vent stack is in that exterior wall and vent out through the second story roof.

 

[Reach4]

I think your photo shows the adjacent room.

Are all pipes in your drawing pretty much perpendicular to the wall?

How long do you propose that yellow line representing the trap arm would be? By increasing the trap arm to 2 inch instead of 1.5 inch, you could make that yellow line 5 ft. Could you make that reach the wall without an extra tier?

Yay, was able to load photos by posting reply.

You can upload a photo when editing by clicking More Options first.

 

[knickema]

My photo shows the back of the peninsula where I cut off drywall so I could see what the plumbing looks like. The kitchen is on the other side of that half wall.

Yes, all pipes in the drawing are perpendicular to the exterior wall. They run to the exterior wall where the vent stack is. They run horizontally inside the peninsula half wall.

It is 44" from the exterior wall to the middle of the one bowl kitchen sink. The pipe would have to enter the exterior wall, so 46"?

 

[Reach4]

So no problem. UPC allows 42 inches for a 1.5 inch trap arm and 50 for a 2 inch.

Add a bit of reach for the trap itself, and you might even be able to do that with 1.5. But 2 inch would be no hardship. No vent pipe needed inside the peninsula.

EDIT: Ahhh... I just noticed the upper left of your wall in the picture. If that is a pony wall that you are calling a tier, I see the problem.

Why no AVCAAV?

 

[knickema]

I'm calling the pony wall a tier, because it creates a 2nd tier of counter. The counter, then the second tier bar height counter, which is the pony wall with plumbing inside. Would prefer a flat level counter, no bar height level.

AVC? Do you mean AAV? They are not allowed where I am.

So, do you think the drawing works? Or would work if I changed all the 1.5" pipe to 2"?

 

[Terry]

A dirty arm is another name for trap arm.
With UPC you can go 42" on 1-1/2" pipe, and 60" on 2" pipe.
That would solve it for you.

 

[knickema]

Okay, so the layout in drawing is good? But better if I changed the dirty/trap arm to 2" pipe? Thank you!!!

 

[Reach4]

AVC? Do you mean AAV?

Yes. Edited above.

So, do you think the drawing works? Or would work if I changed all the 1.5" pipe to 2"?

Just to confirm, the new trap arm will be at right angles to where the old trap arm was. So your drawing shows a view from the kitchen facing at right angles to where the pony wall is in the photo. So if that current photo was facing north, and the trap arm approached the sink from the south, the new trap arm will approach the sink from the west from the west wall.

If that is true, I think you are good. The 45 might not even be needed if you can make the yellow longer by using 2 inch. You can get more reach with the 45 by dropping the trap arm too. Drop the santee by 2 inches, get 2 more inches of extension from your 45. Connect the 45 2 inches closer to the santee, and get another 2 inches more extension.

I am not a plumber.

 

[Terry]

The drawing looks fine as long as you have a 2" cleanout that is accessible.
The two 45's on the vent are considered vertical. That works.
The trap arm can still be 1.5" as long as you have a 2" cleanout there. If you want a cleanout on the trap arm, then yes, 2" to that point.

 

[knickema]

Yes, will be at right angles. Correct, the drawing shows the view from the kitchen facing the plumbing in the pony wall.

 

[knickema]

Thanks Terry. So, best if I have a 2" cleanout on the trap arm, not just on the waste line (pink line).

 

[Terry]

Thanks Terry. So, best if I have a 2" cleanout on the trap arm, not just on the waste line (pink line).

On the pink line is fine, as long as you can get to it.