Venting sink in front of large window

[gedmeyer]

My kitchen remodel is underway. The kitchen sink will be centered in front of a 7ft window. This obviously prevents running a vent directly behind the sink. Considering the window and jackstuds, the nearest open space in the wall to run a vertical vent is about 5 ft to the left or right.

I was thinking an island vent. The building inspector suggested an AAV (which don't seem to get much love around here, so I'm not favoring this approach).

How should this situation handled? I've seen lots of photos of sinks in front of large windows.

I was planning on running a 2" drain. A dishwasher is adjacent to the sink.

 

[Kreemoweet]

A 2" drain for a kitchen sink is required by code where I live, and many other places. It's a good idea. A 2" trap arm is allowed
to be 5 ft. long (or more, depending on exact code in force). I hope you're not intending to bore 2 5/8" holes in all those studs
to run the line.

What's the problem?

 

[Sponsor]

 

[Dj2]

Instead of one 7' wide window, consider two narrower windows, then run your vent in between them. This way you won't have to bore any studs.

I had a similar situation years ago, and that's how I've done it.

 

[gedmeyer]

The window is already ordered and it is a main design feature for the kitchen.

I do not intend on running the drain horizontally through the wall. It's 2x4 and the studs would all be compromised. I have access (full basement) from below. This is why I was thinking of using an island vent configuration and running the drain beneath the floor. The sink+dishwasher would be the only fixtures feeding this branch of the drain.

 

[Reach4]

With an outside wall, you are not going to get enough insulation space in a 3.5 inch 2x4, even without pipes.

 

[gedmeyer]

With an outside wall, you are not going to get enough insulation space in a 3.5 inch 2x4, even without pipes.

The structure is existing. I'm adding exterior foam to get more R value. The building inspector has approved my plans. The window changed sizes and the sink is being relocated.

I wasn't sold on the inspectors suggestion to use an AAV for the sink vent. Posts on this forum seem to generally support my feeling.

 

[Smooky]

Why can't you go around the window?

 

[gedmeyer]

Why can't you go around the window?

It's a load bearing wall. Code does not allow for a large enough hole/notch.

 

[JRC3]

Can you run the vent horizontally through the cabinet/s until you get past the window and studding to get to a wall cavity? Is that allowed?

 

[gedmeyer]

Can you run the vent horizontally through the cabinet/s until you get past the window and studding to get to a wall cavity? Is that allowed?

As I understand, vents can't run horizontally unless they are above the fixture flood level.

 

[Reach4]

As I understand, vents can't run horizontally unless they are above the fixture flood level.

The trap arm can, as suggested by kreemoweet.

 

[Jadnashua]

I think you'll find if you can run it horizontally as high in the cabinet as possible while maintaining the required minimum slope (even a vent needs downwards slope!), it would pass inspection. That would potentially be a problem if those cabinets had drawers. One of the pros would know the minimum height allowed. Depending on how low you could make the trap arm, you could probably still make it work.

 

[Kreemoweet]

... vents can't run horizontally unless they are above the fixture flood level.

Vents may indeed be run "horizontally" below the fixture flood level, if a vertical vent is "prohibited by structural conditions".
Seems to me that that is exactly your situation. At least by the Codes I've worked under. It's done all the time in remodeling
situations. Might want to specifically ask The Man if you can do that.

 

[JRC3]

I was thinking of an island sink when I brought it up...The vent must be brought up to the countertop before it goes all the way back down to the floor. That setup has to have some 45 and 90 degree elbows, though.

 

[Asktom]

Depending on space considerations and what you are doing for a countertop, you could furr out the wall to the height of the cabinets and run your trap arm through that and offset your vent into the existing wall at the side of the window. It would give you an extra wide countertop. Or, you could do it the easy way with an AAV. I am not a fan of AAVs either, but my kitchen has one because of log walls and it works OK. The important thing is that the DWV system is such that the AAV will not be subjected to positive pressure.