vent and drain tie-in question

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MarkY

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New construction, and I'm being made to hook up two sinks (cause my wife says so, and the plumber can't get here before company).
Dilemma:
vent pipe is in the wall about 6" above drain pipe.
Do I bring out the vent with a 90,, and wye it into the drain, and then proceed like any other drain?
Only about half my sinks have this configuration, and I've not seen it before, nor can I find it on any vids.
Thanks in advance.
 
Hmm I'm having trouble picturing this....can you possibly draw up a quick sketch of your idea and post it?
 
Well, not quickly.
Imagine the usual hole for the waste there at the wall, just inside the drywall.
Now, add another hole above the waste... about 6" up.
 
Well, not quickly.
Imagine the usual hole for the waste there at the wall, just inside the drywall.
Now, add another hole above the waste... about 6" up.


Two holes in he wall? That vent pipe should go straight up through the roof of the house. You should only have one hole for the existing drain.
 
You're not getting it, and it's probably why a pic wouldn't help.
The hole above the waste IS the vent.
They're not tied in behind the wall, I need to tie them together under the sink.
I have an elaborate vent system going up, just like the elaborate system going down. 7 sinks, 4 tubs, 4 toilets, but just two penetrations in the roof.
I'll probably just do as I described. I can't see the harm. The waste can't go up the vent stack.
It was just novel to me... never seen it before, and can't find it anywhere else I look.
 
If they are separate drains and vents....you can place them however you please. If they are sharing a drain, each trap must be vented.

We're not getting it because you can't describe what you have. We can't help you if you aren't able to make things clear without showing us pictures.
 
There is a bathroom directly over this bath. My guess is that they ran the vent separate from the waste.(?)
They can't both be waste (unless there was a serious mistake by the rough-in crew).
Run a 90 from the top down into a wye, run the waste into the wye, and then plumb it normally from there?
Thanks, guys.

KitchenInstall.jpg
 
:eek:

Okay so you're saying the top fitting is a 90 going up and the bottom is another 90 going down? Very strange configuration.
you can probably just use a 90 coming out the top and a santee with the branch looking up to connect the 2 as you are describing.


Still very odd?
 
I don't KNOW where they go. I'm making assumptions.
Yeah, it is odd.
Thanks
 
If that pipe on the top is connected the the bottom one inside the wall, then sewer gas is venting right back into the bathroom which is a no no. I can't figure out what was attached to that upper fitting.......another trap??
 
look inside which way do the fitting go.

Like the blue in top sketch or blue in bottom?

Bottom sketch option # 2 --trap arm on top clean out on bottom. :cool:

Scan-141217-0002 (299x400).jpg
 
Last edited:
Yeah that top sketch is odd....just put a tee inside the wall and do away with that top elbow. If that was a clean out up top, that's just redundant. If you needed to snake the drain, just snake by taking the p trap off.
 
My wife is threatening me with divorce cuz I'm here screwing around and now spending time with her. :eek:.. Just kidding about the the Big D word but she is tapping her foot ,, sort of


Se you all later
 
OK... as much as I hate to say it, I think my wife may be right. We have this configuration in 3 of 7 sinks... all 3 anticipated to be low usage.
She thinks the drain comes only from below, and the top hole is for an AAV.
It makes sense. I'd just feel better if I'd thought of it.:eek:
 
I'm curious Now


What do you see looking inside of open fittings A, B, C or D ???

Scan-141218-0001.jpg
 
Hee.
You're a man of many talents... but drawing isn't one of them!
Sorry I didn't get over there yesterday. Long story.
I'll take a wire and a flashlight, and find out if the upper pipe continues up or not. I'm assuming the two are tied, but I'll verify.
Continued thanks, all.
 
back in the day, we used that configureation for co , 2 tee's on top of each other. if the sink was on an interior wall. if exterior, the co would be turned around out to the outside. by upc code, we must install co at kitchen sink and washer machine, not lav,terlet, tub
trap can be used as a co on lav, terlet can be pulled, and tub you can access thru W/O
BUT. the top tee should be 2" not 1 1/2" ..cause..co is supposed to be same size as the drain it serves

you cant legally use both for drains. drain can not be stacked like that, the bottom would not have a vent
 

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