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AMK1834 · Nov 9, 2008, 12:13 PM

When we removed a kitchen cupboard to take out a stovetop and replace it with a free standing range, we found this pipe on the floor. Apparently it is an air vent for the kitchen sink. Question:
Can this pipe be re-routed under the floor at the edge of one cupboard and come back up to be re-joined at the edge of the other cupboard so as to allow the new oven to fit to the wall? See attachment.

ballengerb1 · Nov 9, 2008, 03:33 PM

Yes you can reroute the pipe but you must confirm that it is a dry vent to begin with. You can't reroute downward if this is a wet vent, it would create a Traplike pocket of water and no longer vent.

speedball1 · Nov 9, 2008, 03:57 PM

Something's not right here Bob. The kitchen vent's on the floor? If that's the laterial drain from the sink it should be 18" off the floor and if it's a vent it should be vertical.
I wanna see a picture of the sink cabinet and drainage hook up!! Cheers, Tom

ballengerb1 · Nov 9, 2008, 07:04 PM

Could be a horizontal leg of a vent that goes vertical elsewhere. AMK needs to do more homework before cutting the unknown pipe.

speedball1 · Nov 10, 2008, 05:13 AM

Originally Posted by ballengerb1

Could be a horizontal leg of a vent that goes vertical elsewhere. AMK needs to do more homework before cutting the unknown pipe.

If that's a kitchen "horizontal leg of a vent that goes vertical elsewhere" Then I'm looking at a "S" trap Unless it's a vent from a basement fixture. I wanna see a picture of the kitchen sink drainage!! Cheers, Tom

AMK1834 · Nov 10, 2008, 07:59 AM

Thanks for your answers!
According to the builder, the vent is attached at a 90 degree angle from the drain, under the cabinets, on the floor. It goes around behind the cupboards and then into a vertical stack.
I am attching pictures of the drain but I don't think they help much.

speedball1 · Nov 10, 2008, 09:01 AM

AMK,
Thank you for the pictures. It's all clear now. You may not route it under the floor and then come back up. That would put a running trap in the vent and that's a big no-no. You will have to lower the trap and run the vent under the floor unless you could install a offset that could run through the dishwasher under the tub. Good luck tom

AMK1834 · Nov 10, 2008, 09:11 AM

If it is just air, could the pipe be 90 degrees into the wall and then back out so that it is still on the same plane?

ballengerb1 · Nov 10, 2008, 06:59 PM

I don't see any trap in your pics, where is the trap?
Bob! The trap's located under the floor line. That's why he could run the vent on top of the floor.

AMK1834 · Nov 11, 2008, 06:53 AM

OK you guys are confusing me.
If it is an air vent can it or can it not be diverted either into the wall or under the floor and back up again?
Thanks.

speedball1 · Nov 11, 2008, 07:07 AM

Originally Posted by AMK1834

OK you guys are confusing me.
If it is an air vent can it or can it not be diverted either into the wall or under the floor and back up again?
Thanks.

You may not route it under the floor and then come back up. That would put a running trap in the vent and that's a big no-no. You will have to lower the trap and run the vent under the floor unless you could install a offset that could run through the dishwasher under the tub.

AMK1834 If it is just air, could the pipe be 90 degrees into the wall and then back out so that it is still on the same plane?

Now THAT you could do providing you maintained slope. You just can't drop under the floor and back up again.

If it is just air

There's where you make a mistake in judgement. It's not just air. Why do you think we give vents pitch back to the drain? Becase rain water can drain back to be disposed up. If you built a running trap by dropping down under the floor and then come back up the rain water would be trapped and build up to block the vent. Congratulations! You have come up with your own solution. Elbo into the wall and back out again. Just maintain some pitch on the offset and you'll be just fine. I hope I;ve explained everything to your satisfaction.
Good luck and thank you for rating my reply. Tom

AMK1834 · Nov 11, 2008, 09:14 AM

Thanks for everything!

ballengerb1 · Nov 11, 2008, 05:12 PM

Vents can be wet vents or dry vents. A dry vent never , ever has awter in it and they can not go down and back up. A dry vent can go under the floor but like Tom points out, your trap is under the floor and we can't see it or how its is connected. Can you get pics from below the floor? I need to totally defer to Tom since I have never seen a setup like this. Tom's the plumber here

mygirlsdad77 · Nov 11, 2008, 05:28 PM

I'm a bit confused here too. I see no trap under the sink(above the floor) Is it possible that your original pic is of the drain. Possibly. You can offset it into the wall if you desire. But I see a lack of trap and vent if I am right about your original picture. Looks like they just ran the drain in the toespace of the cabinets. Need more pics and info as to what you really have here.

letmetellu · Nov 11, 2008, 05:38 PM

In my opinion you could cut the pipe and put it in the wall on the same level that it is on now. If at all possible I would use two 45 degree ells on each end of the cut to turn it back into the wall.

I am a little confused about where the trap or traps are for the sink. Also I would like to know what the wye is for in the pictures that show under the sink, it may be the drain from the dishwasher, it is hard to tell

letmetellu · Nov 11, 2008, 05:42 PM

After looking at the picture showing where the range is going I studied the ABS pipe and to me it looks that the slope on that pipe is from left to right, so do you have something that has a drain line in the area left of the range, something like the condensate from the air condiitioner, of maybe a water softner?

mygirlsdad77 · Nov 11, 2008, 05:48 PM

Looks like the wye is for dishwasher, and a tee for a cleanout right at base of cabinet. No trap no vent.( not even an aav, which doesn't matter because there is no trap). I do agree with letmetellu. If your current sink works just fine, then you will have no problem running line into wall for a distance and back out, as long as you keep same slope as you have now on whatever that pipe is. You will have to drill some holes in the studs in the wall, or notch the studs(would prefer drilling holes).

massplumber2008 · Nov 12, 2008, 05:24 AM

Hi all...

My biggest concern here isn't the drain/vent as much as it is an UNCAPPED GAS LINE..? AMK1834.. please install the flare fitting back into the gas line and then CAP the end of the gas pipe. Some shutoffs fail and sometimes when working around the pipe shutoff handle can get snagged... just as an extra precaution as you deal with the vent, plug that gas line... ;)

Good luck...

MARK

Milo Dolezal · Nov 12, 2008, 07:40 AM

It is kitchen drain that runs under kick plates. No, you cannot reroute it under the floor unless you reroute entire run under the cabinets. You will be better off if you 45 it in/out of the wall to by-pass stove opening. If you are lucky, you have trap under the kick plate. But considering overall look of the work done, it may not be so...

Btw: Who was the original plumber ? Mickey Mouse ?

massplumber2008 · Nov 12, 2008, 08:11 AM

I think Milo called this one... :)

Hopefully AMK1834 will return

Nice job!