[amadogon49]

Hello,

First, happy new year to all.

I'm in the middle of doing a kitchen remodel, and due to the location I've chosen for the sink, which will sit under a window, which is on an exterior wall, I won't be able to simply extend the trap arm in the wall, due to the location of the studs that support the window header. (see picture).

My plan is to run the trap arm flush in front of the studs/drywall, inside the cabinet, it would run about 4-5 feet, within code, for a 2" pipe. At this point it would turn back into the wall to connect to a vertical revent/drain. The revent would be 1 1/2", and the drain itsef would be 2". Would I affect the trap in anyway, based on the length of the trap arm, and/or the turn I would have to make back into the wall to connect to the vertical pipe? Once I'm connected back into the wall the vent itself would attach to an another vent stack, which, in turn connects to a horizontal vent branch one floor above, and eventually, to the main stack, and out the roof. The drain would need to go about 10 feet to connect to another 2" drain which in turn connects to the main soil stack in the basement. (see picture).

I posted most of the questions in the picture attached, but in essense:

1) Is the design sound?
2) The type of fittings I would need at the various junction points in the vent and drain sections?
3) Is the sizing for the drain/vents correct?
4) The length of the vents and drains, is this within appropriate limits based on the design.

http://img87.imageshack.us/img87/2171/reventsink.jpg

[mygirlsdad77]

All looks good to me. Are your outside walls 2x4 or 2x6? If 2x6, there shouldn't be a problem drilling the studs with a 2-9/16' bit. We even do it with 2x4 wall all the time. Never been a problem during inspection for us. However, the way you plan on doing it would be just fine too. Use long sweeps on the drain and short sweeps will be fine on the vent. Yes, tie your trap arm in with a 2x1 1/2x2 tee.(if you were just a little closer to the vent, I would suggest an 1 1/2 trap arm, but since your out there, two would be safer from an inspection stand point. An 1 1/2 san tee flipped upside down for the vent tie in. Now, you can use a two inch san tee for the drain tie in, but, If there's room I opt for a two inch wye with a 45, especially if another fixture drains in above. But like I said, 2 inch san tee in the vertical is up to code(at least in my area). Looks like you've got a good handle on this. Please let us know how things work out.

[massplumber2008]

Hi guys...

MGD77 pretty much said it all... ;) I would also confirm that you can drill even 2"x4" studs as we do it all the time, too... but your way sure looks less labor intensive!

To sum up:

Use long sweep 90s on the drain.

Use regular 90s for vents

Use a 2"x1.5"x2" sanitary tee on the vertical for the kitchen sink drain/vent/sink drain branch.

Run 2" to the sink and install a 2" cleanout under the sink before reducing to an 1.5" PTRAP

Use a 2" wye and 45 to connect into the main drain branch line if possible, but like MGD77 said, a 2" sanitary tee would be OK here if the drain pipe you're connecting to is going vertical (as it looks in the drawing). I'd also install a 2" cleanout here.

Invert 1.5" sanitary tee fitting for the vent tie into the other vent,

Hang all pipes every 3-4 feet.

Pitch needs to be 1/4" per foot of pipe for the waste and a minimum of 1/8" pitch per foot of vent piping.

Good luck!

Mark

[rojo1]

Can you use a remote vent valve under the sink? These are used quite frequently in new and mobile home
Construction.

[mygirlsdad77]

Hi rojo1. Yes, many areas allow aavs, but a true vent is always the best way to go (no parts to fail).

[amadogon49]

Hey Guys:

I recently saw this explanation of what is called a dirty arm, which apparently is what I'm tryig to accomplish with my design. The page also refers to a standard roughin, which in comparison to a dirty rough-in, has a very short trap arm, rather than a long one, which from my view has one advantage, I don't have to use 2" pipe for the arm. Don't know which way to go, what would be better in your eyes guys? Either way, I still would have to bore through 2x4's which I'm still hesitant to do, but since I'm only dealing with 1.5" pipe now until I hit vertical maybe I can pass the 40% code issue? What do you think guys? Here's the web page with the dirty vs standard roughin visual.

Thanks again, for all your help.

Amado

http://www.plumbing-geek.com/trap-arm.html

[amadogon49]

Hey Guys,

Actually one more thing. In my original design, are there any height thresholds I have to minimally reach at either the vent/drain san tee on the side wall, or where the long trap arm connects to the p-trap outlet? Or, in the case of the standard rough-in, in the web page I posted just previously, where the revent takes off which is right under the window?


Thanks again,
Amado

[massplumber2008]

Hi Amando

You don't have to use 2" for any of these setups...;) Code only requires 1.5" in most states that I know of.

With that being said, I'd opt. for the one that requires drilling the fewest holes. Otherwise, in my opinion, either way is fine!

Go as high as possible with the vent, but just under where the nails may extend into the studs from above.

Mark