Another vent thread

[rbeddoe]

Hello folks. First post here.

I am in the process of remodeling the kitchen in our 99 year old house. We're past the halfway part now and trying to wrap up the kitchen stuff. Moved the sink to a new location below a window. As a result, we are now about 2 feet away from the vent with no easy way to attach the vent in the "traditional"? location just past the p trap before it turns down to drain.

I thought I would use the method used in island drains but that almost seems like overkill.

I am an engineer by trade, but I would not say that makes me an expert at being a plumber.

It's my understanding that the main purpose for the vent is to keep a vacuum from forming inside the drain which could ultimately drain the p-trap.

The more my engineering brain thinks about it, the more it seems I should be able to vent the line under the floor. The attached model shows what I have in mind (not to scale). Would this work? Would it pass code? I am using 2" PVC for the vent and drain

 

[Twowaxhack]

Maybe you have room to run the drain along the back of the cabinets from the vent.

 

[rbeddoe]

Thanks for the response. I would like to avoid running pipes through the back of the cabinets, but that is a possibility.

Would this still function as a vent?

 

[rbeddoe]

I presume this is what I'll have to do.

 

[rbeddoe]

My second image is the one I'd like to use. I've found some similar examples that show this as a possibility

 

[Twowaxhack]

I presume this is what I'll have to do.

This ones good if it’s within 3’ for 1.5” or 5’ for 2”.

 

[rbeddoe]

scratch that. We will have a dishwasher there and there is no clearance behind the washer.

 

[rbeddoe]

So I am back to thinking about the "Chicago loop" style setup.

 

[rbeddoe]

or AAV, but I'm guessing that would be opening up a can of worms. I would prefer to not use one.

 

[frodo]

2 different ways, this is code


this used to be code, i still install this and have never had a problem with it in 37 years of plumbing

 

[Twowaxhack]

We did the same without the vent in the nearest wall and we used 3x2 tee and a 2” ptrap.

Later on they wanted the nearest wall vent, they wanted it to be at least 2” and have a cleanout in it since it wasn’t washed by a fixture.,

That’s how it went around here.

 

[rbeddoe]

Thanks guys.

I've been trying to do something like your first image, Frodo. But in my case, sewer goes in the opposite direction from this diagram and I can't seem to find anything showing that setup.

 

[rbeddoe]

Ok, that doesn't look right either. Vent should be in the right side of the loop? And drain on the left?

 

[frodo]

Thanks guys.

I've been trying to do something like your first image, Frodo. But in my case, sewer goes in the opposite direction from this diagram and I can't seem to find anything showing that setup.

View attachment 27884

 

[frodo]

 

[rbeddoe]

Could I do something like this:

 

[rbeddoe]

View attachment 27901

Wish I could do something like this, but I cannot go outside the studs. There's a dishwasher going against the wall where that top run is

 

[Twowaxhack]

I’ve done a few hundred where we just stubbed a 3” pipe up under the sink. With a plug in the top. 2” trap.....

It was all code approved by our inspectors.

You’ll never fill a 3” pipe up through a 1.5 end outlet waste ✌

I service a few of these homes and my parents live in one. Its working flawlessly.

Plumbing is a theory.........

 

[rbeddoe]

Two...are you saying I could just have a 3" drain? My sewer is not 3" however and wouldn't be able to take 3" all the way there. At least, not yet. Maybe in the future.

 

[Twowaxhack]

Two...are you saying I could just have a 3" drain? My sewer is not 3" however and wouldn't be able to take 3" all the way there. At least, not yet. Maybe in the future.

View attachment 27903

I’m saying it would probably work but it doesn’t meet your plumbing code.

Just like you’ve drawn but the trap is 2”.
Here’s a pic.