Drain location for kitchen sink rough-in

[JMingrone]

Hi all,

I'm roughing in for a new kitchen sink/base cabinet and was wondering what the experts recommend for where the drain should be brought up. The kitchen is gutted, so I have a lot freedom on where to put it, except it's a easier from down below in the basement to put it no closer than 16" off the wall. This would put it more towards the front of the base cabinet Is this ok?

As far as left-right position goes, i saw this picture on the site which shows the drain coming up on the side, rather than the center:



This is pretty much what I will have except my dishwasher will be on the right. This looks pretty good, so what i'm thinking is bringing the drain up all the way to one side and forward of the sink center. Anyone see any flaws with this design?

Thanks

[JMingrone]

Sorry, dishwasher is to the LEFT of the sink...

[hj]

YOU want the drain on the side that is farthest from the disposer. If you are bringing the drain up through the floor, how will you avoid having a ""S" trap? The dishwasher location is irrelevent.

[Terry]

We put the drain in the back wall.
The drawing above is just meant to show how things drain. Which is hard to do with a front on picture.

for a deep sink, we stub out the sink trap arm at 16" above the floor.
You you have a single bowl and disposer, then offsetting either way 8" works.
If you have a double bowl, then aiming for the bowl drain opposite of the disposer works fine. You can miss by a few inches and the swivel of the trap will still pick it up.

[big2bird]

We put the drain in the back wall.
The drawing above is just meant to show how things drain. Which is hard to do with a front on picture.

for a deep sink, we stub out the sink trap arm at 16" above the floor.
You you have a single bowl and disposer, then offsetting either way 8" works.
If you have a double bowl, then aiming for the bowl drain opposite of the disposer works fine. You can miss by a few inches and the swivel of the trap will still pick it up.

I need to ask here. I offset my in wall work 10" to the left for the dual bowl kitchen sink, but alas the disposal side of the sink is on the left as well. Am I screwed?

[kreemoweet]

JMingrone, you say you have a sawzall, so put it to good use like so: cut out ALL of that old, tired, clogged-up, undersized
1 1/2 galvanized drain line to where it connects with a big house drain. Replace with 2 in plastic drain with sanTee/trap adapter
for the sink to connect to. Probably there's an 1 1/2 galvanized vent line above that in decent condition, which you can connect
to with a rubber coupling. Then you'll have a normal drain setup which won't require cabinet surgery.

[cacher_chick]

The drain is in the wall because that is the only logical place to continue the vertical section of vent. The vent must run vertically upward at least 6" higher than the rim of the sink. From that point it can continue to run vertical or horizontal if need be to get up through the roof.

[JMingrone]

Thanks to all who replied.

RE the drain in the wall: Actually, that's where it originally was. When I demoed the wall I discovered the old wall drain (1-1/2" galvanized pipe) which someone capped off with a dish rag (no kidding). Unfortunately, the threads were rusted out, so I sawz-all'd the stub off flush with the wall, and moved to plan B which was to drop the drain thru the floor like the previous renovator did, 5 ft to the right (I'm moving the sink back to its original location).

So looks like I have at least 3 options:

1) Figure a way to adapt some kind of fitting to the sawed-off stub and put the drain in the wall (it's 13" off the subfloor). Is there an acceptable way to do this?

2) Cut out the old 1-1/2" T and put something else in its place to drain thru the wall. What would go there?

3) Cap off the wall drain and go back to the original plan of dropping the drain thru the floor. The previous setup had an "S" trap as hj noted, and I suppose i'd need to do the same. Are "S" setups "ok" or to be avoided?


Interested in suggestions.

Thanks,

Jay

[cacher_chick]

S-Traps are not permitted and will fail any plumbing inspection. There is no approved way to install a drain going down without a vent going up.

A plumber would install PVC pipe in the wall, with a sanitary tee around 15" off the floor. The sanitary tee would have a trap adapter installed which would connect to the sink's trap arm. The vent would run upward from the top of the sanitary tee. It can tie into another vent which goes through the roof, or can be run through the roof on it's own. The drain would run down from the bottom of the sanitary tee, and into the basement or crawlspace to tie into the existing drainage system.

This is how plumbing is done. Every P-trap must be vented to prevent siphoning.
When a trap siphons, sewer gas, drain flies, and other things you do not want will come back into your house.


Here is a nice link to Bert Polk's plumbing tips