Inspector discouraged AAV, which option works better?

[puyehue]

(UPC /California Plumbing Code)
As suggested by you guys, I called my inspector and he encouraged me to make it work without the AAV.
But he didn't explicitly say how to accomplish it. He did say he wasn't going to put a tape on it!
He just wants it to work properly - I think he wants to see a good system, perhaps not necessarily to the letter of the code. (perhaps this will make you cringe, but such is my situation.)

BTW, the windows fill the wall so I have to go down, can't take trap arm left or right in wall.
Can/should I put the trap below the floor, like a shower?
Use 2" drain and go into crawlspace, to achieve more rise on vent pipe?
Not to scale below! It will surely be less than 45 degrees on vent pipe I think!

Let me know what you think ... I'm not easily offended.

Thanks!

 

[Jadnashua]

You might be able to use a loop vent like they use in an island where they can't go up.

An AAV is generally only allowed when there isn't a better way. They do fail. Some places don't allow them at all. An atmospheric vent should always work...nothing to break.

 

[Sponsor]

 

[Reach4]

Neither of your proposal drawings would be allowed. How far from the nearest side of the windows?

AAV will be needed if you cannot run a vent pipe, that is 6+ inches above the rim of the sink before it goes horizontal.

Show the inspector your two proposal drawings, and he will know that you unsuccessfully tried to avoid the AAV.

 

[puyehue]

Thank you reach4 and jadnashua...

The windows fill the whole wall.
So, I think I'm better do a petition for the AAV from the county building official.

And/or, I'll explore the island vent... maybe better to avoid paperwork.

 

[Reach4]

The windows fill the whole wall.

How about just around the corner from the windows. Window go around the corner too?

And/or, I'll explore the island vent... maybe better to avoid paperwork.

I am not saying that you would need more paperwork for the AAV. I figured you already had those alternative drawings, and might show your discarded efforts.

I don't think the UPC allows an island vent for your situation.

 

[puyehue]

Countertop will come up to window, 36"
the 4x4 posts are bearing, 6x6 headed above those.

 

[puyehue]

How about just around the corner from the windows. Window go around the corner too?


I am not saying that you would need more paperwork for the AAV. I figured you already had those alternative drawings, and might show your discarded efforts.

I don't think the UPC allows an island vent for your situation.

See photo regarding windows...

I think I do need to request by paper to the building official for the AAV. But, I agree with you that I have a good case.

I'll look at the CA building code and see if I can find anything.

Thanks for your replies!

 

[puyehue]

https://fremont.gov/DocumentCenter/View/7197/ISLAND-SINK-VENTING

Does this (link above, 2016 CPC) look good to you?
I could fit it in one of the open stud bays under right window....
I suppose I could also instal it after cabinets? Which is most common?

 

[Jeff H Young]

I probebly should have but still have never installed an AAV from what I see on this site around the country they are so darn common.
One possible option is to come up in side wall with a 2 inch trap and trap arm up to 5 foot long put it as far to the back as possible extend it to sink after cabinet is installed. Or an Island vent a bit of work from underneath and your waste line needs to be kind of low for the fittings to work depending which way joists run. So he didnt like the aav and sometimes they dont like Island vents ? ask him (I had inspectors complain of that too told me I could have vented it as I described with a 2 inch arm) .

Ok getting long here but I usually install island vent for inspection and cut it off for cabinets to be installed. couplings. They want it coming up as high as possible which might mean not coming up in stud bay because the vent wont be as high as the bottom of the rough counter top . Dont know why framer has 6 inches of lumber underneath the window. (im not a framer but the load is on the header and posts).
Like I said Im from Ca Ive never put an AAV . but its sure easy, I will some day when I start doing more small jobs

 

[puyehue]

Hi Jeff
Thanks for going long here. I'll look at the trap arm from the side wall. I think that is what Reach4 was probably referring to. It also looks like a 1-1/2" could go 3' 6". I could vent up into rafters and out there.

Also, I now have a good vision for the island sink - inside the cabinet - cut off and couple. I have 30" below joists and main in on the ground, so good there. Those windows are recessed and therefore have a 2x4 on top of ply and 2x6... I agreed, inside cabinet would be best to get vent as high as drainboard.


Thanks!

 

[Reach4]

In UPC, you could increase the trap arm to 2 inches and go horizontally as much as 5 ft.

 

[Jeff H Young]

drawback on not being inside the wall (island) is it takes up room can make things dificult on a deepsink hooking it all up. Its a kitchen Im assuming. if you come from right side cant have a dishwasher on that side. trap arm size depends on length as you said and I hate re doing stuff so I take the length seriously Ive been called on it. As reach 4 said about uncertainty of allowing an Island vent the way I understood its not simply a plumbers choice option its in liew of a normal install when required. I was forced to tear out an Island sink rough in by Inspector because it wasent the only way to do it (20 years ago). My superintendant told me to put in and when called on it told me tear it out. I didnt challenge the call but followed bosses orders.
Kitchens can be rough with all the wood and they dont like butchering the studs like old days

 

[Jeff H Young]

In UPC, you could increase the trap arm to 2 inches and go horizontally as much as 5 ft.

Yes done it many times everyone wants windows ha ha

 

[wwhitney]

My suggestion:

If the sink drain is within 5' of the sidewall, go with the Jeff Young's idea.

If the sink drain will be farther than 5' from the sidewall, put a 2x1.5x1.5 san-tee in the wall behind the sink cabinet, offset towards the closer sidewall. Run the 1.5" vent from the san-tee as follows: immediately 45 within the wall to traverse beyond the sink cabinet while rising. Before hitting the sill plate or a 4x4 post, and low enough to stay below the countertop, use two 45s to jog out of the wall and go horizontal tight to the face of the framing. Run to the sidewall and turn up with a long turn 90. Modify the cabinets to deal with the vent pipe obstruction. E.g. use cabinets 2" - 3" less deep in front of the pipe. Or fur out the wall 1.5" everywhere and make the counter an extra 1.5" deep.

the 4x4 posts are bearing, 6x6 headed above those.

Sure would have been easier if the 4x4 posts were flush with the outside of the 2x6 framing instead of flush with the inside. Then you could just notch the 2x6 cripples by 2" and run the vent horizontally behind the drywall.

Cheers, Wayne

 

[Jeff H Young]

My suggestion:

If the sink drain is within 5' of the sidewall, go with the Jeff Young's idea.

If the sink drain will be farther than 5' from the sidewall, put a 2x1.5x1.5 san-tee in the wall behind the sink cabinet, offset towards the closer sidewall. Run the 1.5" vent from the san-tee as follows: immediately 45 within the wall to traverse beyond the sink cabinet while rising. Before hitting the sill plate or a 4x4 post, and low enough to stay below the countertop, use two 45s to jog out of the wall and go horizontal tight to the face of the framing. Run to the sidewall and turn up with a long turn 90. Modify the cabinets to deal with the vent pipe obstruction. E.g. use cabinets 2" - 3" less deep in front of the pipe. Or fur out the wall 1.5" everywhere and make the counter an extra 1.5" deep.


Sure would have been easier if the 4x4 posts were flush with the outside of the 2x6 framing instead of flush with the inside. Then you could just notch the 2x6 cripples by 2" and run the vent horizontally behind the drywall.


Cheers, Wayne

Thats another way too Wayne and again though a real tough inspector dosent like offseting the vent less than 6 inches above floodlevel of fixture unless structural conditions require it. Thats UPC . Technicaly their arent a lot of options, But Ive done it all of these ways the main way is a san tee with vent straight up or on a 45 until 6 inches above flood level . the other choices have discretion of inspector.

 

[Jadziedzic]

What about a combination waste & vent setup? Can you fit a 3" vertical pipe in the space under the window, connected to a 3" drain below the floor?

 

[wwhitney]

a real tough inspector dosent like offseting the vent less than 6 inches above floodlevel of fixture unless structural conditions require it.

Agreed. But if the OP's situation doesn't meet the criterion of "structural conditions require it," I'm not sure what does.

Cheers, Wayne

 

[Reach4]

What about a combination waste & vent setup? Can you fit a 3" vertical pipe in the space under the window, connected to a 3" drain below the floor?

That would be a cool and effective way, but it looks to me as if UPC wants that for below-the-floor stuff.

 

[Jeff H Young]

Agreed. But if the OP's situation doesn't meet the criterion of "structural conditions require it," I'm not sure what does.

Cheers, Wayne

It looks to me like a 2 inch dirty arm would work easily from side wall. so there isnt a structural condition requiring anything that he has pointed out , other than the stack wont go under the window which is fine , but why cant it go in side wall? there can be other factors like dishwasher perhaps an undersink fridge or whatever fancy thing they might have there. Ive been there not always a walk in the park.

 

[puyehue]

Thanks for all of your thoughts!

Here is a better photo of the right wall corner. There is a 4x6 to contend with there, but that should not be a problem in a normal situation.
And, the sink drain will be about 42" from the wall, so the 2" @ 5 feet will work.

But, Jeff mentioned you can't have a DW between sink and wall.
There is a (*&%$#) DW that needs to go there!

So, question: with the cabinet being ~24" and dishwasher at 22 1/4", could I notch the cabinet, drywall and a little wood to take the trap arm behind the DW? I would have to come out of the wall and make a 45 toward wall and 45 back flush. Can a trap arm have bends?