Vent loop for sink drain under window...

[ringofFire]

I plan to vent my kitchen sink under a window like in the image. The yellow would be vent pipe. My question is, is this ok? Or do I have to loop back down to the main drain line as seen in red?

 

[breplum]

Definitely NOT ok. Code does allow a straight, low vent under a window if you use drainage fittings (long sweep 90 on the far elbow that turns up.

 

[ringofFire]

Definitely NOT ok. Code does allow a straight, low vent under a window if you use drainage fittings (long sweep 90 on the far elbow that turns up.

This is just a quick drawing, not showing fittings. So if that top turn is a long sweep, this would work?

 

[breplum]

NO, you cannot do anything remotely like what you show.
Island vents look like this

 

[ringofFire]

NO, you cannot do anything remotely like what you show.
Island vents look like this View attachment 43038
View attachment 43039

I can't do anything remotely close? I'm having trouble seeing the big difference from what I'm showing... Looks almost identical if I add the red line, as I asked in the post. Again, I'm not showing fittings or even slope.

 

[GReynolds929]

Where is the floor level and where is the window bottom. You are allowed to come up as high as possible under the window and horizontal over time the stack.

Or you can run the trap arm horizontally to the vent stack if it is within maximum length requirements.

 

[ringofFire]

Where is the floor level and where is the window bottom. You are allowed to come up as high as possible under the window and horizontal over time the stack.

Or you can run the trap arm horizontally to the vent stack if it is within maximum length requirements.

That's actually how I originally had it, but it requires me to build a small wall to go horizontal like that. I don't want to put the pipes in the existing wall because I'd have to cut through many king/jack studs to get there. I plan to come out of the floor instead since I have a crawlspace, similar to the attached image:

 

[user 32496]

Seems like a good reason to use an AAV (Air Admittance Valve).




They are approved in IPC jurisdiction and may need approval in UPC jurisdiction

...or, just put it in and tell them to mind their own business.

 

[MicEd69]

I can't do anything remotely close? I'm having trouble seeing the big difference from what I'm showing... Looks almost identical if I add the red line, as I asked in the post. Again, I'm not showing fittings or even slope.

I'm not sure what breplum was referring to either. Yes, add the red line as sown on your drawing, use wyes at the connections to the horizontal sewer line, use a combo at the connection where breplum said in his drawing, and add the cleanout where breplum said as well.

I don't like AAVs unless there is no other reasonable way to vent the fixture. And as you have this layout which will work, I personally would prefer it over an AAV.

 

[ringofFire]

I'm not sure what breplum was referring to either. Yes, add the red line as sown on your drawing, use wyes at the connections to the horizontal sewer line, use a combo at the connection where breplum said in his drawing, and add the cleanout where breplum said as well.

I don't like AAVs unless there is no other reasonable way to vent the fixture. And as you have this layout which will work, I personally would prefer it over an AAV.

Thank you! Yes, def trying to avoid AAV.