Island sink drain with disposal

We had done a remodel 3 years ago with an isalnd kitchen sink with a disposal. The sink is a dual sink and the disposal is on the larger left side.

I had done the drain myself as the pumbing contractor was a jerk and never showed up, etc. Well I just had the final inspection done and the plumbing inspector said that what I did was wrong and it needs to be changed, It has worked fine, but I now need to correct it. I should have had him tell me exactly what he wants, but I didn't. Before I try and contact him , I was hoping that someone here can set me straight on this.

What I have is the following:

One 2" PVC drain pipe coming up from the basement below. There isn't a second one to make an island loop with.

A dual sink, with a disposal on the larger left side, which puts the disposal dead cenre underneath. There is a plain drain on the smaller right hand sink.

The 2"PVC is dead center against the back wall of the base cabinet.

Can I use one of those end of line vents?

What is the correct way to route the disposal drain and the single sink drain to the 2" drain pipe?

Thank you in advance for any help.

From what I see you essentially have it right until you get to that S-Trap.

What have you got for pipes below that sink in the basement that we might possibly get a proper vent going? That is always preferable to an AAV which may or, may not be allowed in your area.



"Say Dr. Bob what's that poo smell coming from under your sink?"

"Oh that's just the AAV I've go installed under there instead of running a proper vent! They allowed me to use it. They said it was proven technology used in tin houses on wheels all across this country"

"Hey! You wanna hear the farting noise it makes when I let a sink load of water out?"

That 2" pipe is accesible down below as the basement isnt finished. I would need to cut a 2" hole in the 3/4 plywood and then somehow extend it up into the cabinet bottom which is 3-4 inches above that to get another pipe up into this area, if that is what you are thinking.

Thank you for the reply

I'm just wondering whats down there that might turn into a loop vent

drain

What your picture shows does not tell us anything about whether the plumbing is set up for a proper island vent or not. We also do not know if AAV's are permitted in your area, but when used on an island drain, they can create their own problems where the sink will not drain, even though everything else works properly. And it can happen even if the sink drain is not plugged up.

Ok, I will find out if AAVs are permissible or not.

Let's assume that they are not.

What is required here in addition to what I have to make this right?

You say that the picture doesn't show you what you need to know?

What in addition to that do you need?

In the unfinished basement below, there is a 2" pvc pipe that has a 90 degree elbow in it that comes up through the floor as you can see in the picture.

In the below pictures, the first one is the 2" coming down from the under sink area, along with the h/c water, electric and central vacuum.

That pipe runs north, over the large I beam in the second picture and tees into the 2" pipe that is running east parallel to the I beam. The tee into this run is not pictured.

This makes 2 more 90 degree turns then a 180 into the 3" that goes through the block wall directly into the sewer line on the other side of that wall in an adjacent crawl space.

Next to the bare bulb light in the second picture you can see a two inch pipe that tees off of the run parallel to the beam that is a vertical vent stack that after running north over the heat duct ultimately goes up vertically through the second floor and out the roof.

Drawings of loop vents that I have seen require a second 2" pipe up into the under sink area . I can access the pipe below as seen in the first picture to facilitate this if necessary.

Thank you

Somewhere on this forum I'm pretty sure I've seen a picture/diagram (from Terry, maybe?) of proper island sink venting.

There should be cleanouts on the drain and on the vent as pictured below. I would actually put the drain cleanout above the sani-tee for the trap to facilitate being able to snake the line with water running.

For me to get to the vertical vent stack would require a horizontal run of approximately 8 feet to tie in with an existing horizontal run that ultimately goes vertical after an additional 6 feet or so.

Is there any problem with this and is there a pitch requirement at all to the horizontal vent runs?

Thank you

Horizontal vent runs must be pitched toward the drain at 1/4" per foot just like a drain.

There's a limit on the total horizontal run verses vertical, but I don't know the numbers.