[www.dropbox.com]

The link above has three images in it which show the waste pipes under the double kitchen sink in a house we just moved into about 5 months ago. Notes are written into the images to show several issues, including:

1) The horizontal pipe from the disposal to the tee in the other side actually slopes UP, as does the horizontal pipe from the non-disposal side to the point where the pipes exit into the wall. Doh!

2) The tailpiece out of the non-disposal side is too short, thus requiring the upward slope from the disposal to the other side. This slip joint connection has come apart twice (due to the tension of the upward sloping horizontal pipe straining to reach it), sending water out onto the floor.

3) Right side of sink, especially, drains slowly. This is the side WITHOUT the disposal. I haven't taken anything apart yet, but shining a light down that side looks like there might be some kind of obstruction.

I'm open whatever would be the best fix for this, though I really hate to have to tear into the wall itself. If a completely different piping method is best for all of this, I'm all ears.

1-remove the disposal, 2- lower drain inlet in the wall and a possible 3rd is to install a deep seal trap. What's the measurement from the underside of the sink (where the disposal connects) to the centerline of the disposal outlet? There are some Insinkerator models that are 6" and yours looks like it's more than 6".

his would require cutting the pipe at the wall and gluing on a PVC "Y" with a couple of trap adapters glued into that "Y".
using 2 traps eliminates the upright tee and will give you more slope towards the wall.
if you face the side of the "Y" so it is looking at the sink with no disposer, i'm guessing this will work.
you need a disposer 90 to make this work.
ignore the two 45's in this picture.

@ packy,

the OP's elevations will NOT work for your plan, albeit your plan will improve the situation

as per my 'visual' and the OP's description the wall stub-out is almost the same elevation as the disposal outlet

IMO:

1 - lower the wall stub-out

or

2 - get a different (higher) disposal

or

3 - 'cobble together' some deep seal trap (which presents another set of maintenance issues re: clogging)

or

remove the disposal, don't worry, be happy

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Ok, so after a little more measuring, an update:

The wall exit point for the pipe IS about 1-1.5" lower than the disposal outlet. I was sure hoping to NOT have to tear into the wall, but if that's the only way to do it properly . . .

Also, the distance from where the disposal connects to the metal drain collar (not sure what it's really called) to its outlet is in the 5.5 - 6" range. Definitely not more than 6".

[www.dropbox.com]

If the wall stubout is lower than the current disposer outlet height, then you should be able to configure something to get it to work.

The problem is the disposer outlet pipe coming straight across require you to put in a tee below the tailpiece of the right sink which further lowers the p-trap.

Packy suggestion to use two individual p-traps eliminates the need for that tee. But it's not clear now much room you have behind the disposer to put in that fitting and the p-traps.

You can also try to bring the disposer and the right sink drain to a mid point, join them with a center outlet baffle tee, then a p-trap to the wall stubout.

Finally you may be able to get it to work by using a slightly longer tailpiece out of the sink, then take the U bend of the p-trap and flip them backwards, adjust all the pipe slopes. I have seen plumbers do this but not best practice.

i think it will work.
look at the picture i posted. the disposer outlet is (maybe) 2 1/2 inches above the wall outlet.
there sure appears to be enough room to elevate that trap an inch and make it work.
the other side of the sink is not a problem.
if it were my job, i would use a double "Y" at the wall with a cleanout in the run and hard pipe it all.
mass code requires us to do it that way.

'my' insinkerator 444 evolution measures 4-1/4" from the collar (higher than 'your' unit)

since your wall stub-out is PRESNTLY 1+" lower you (or a plumber) WILL be able to pipe it properly withOUT opening the wall


re-configure piping and/or new disposal

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

as per 'oddjoblarry'


reverse the trap and add a short piece if necessary - ugly, but workable





the 'deep seal' principle




@ packy: have you cleaned up yet

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

4 1/4" from bottom of the sink? ISE website documentation states 6".

steve, our friend from SC said from the 'collar' to the outlet.

Can you tell me what the collar is, and also what this means, "4-1/4" from the collar (higher than 'your' unit)"?

on the east coast, south of the mason/dixon line, they call this an ISE mounting collar.

I really appreciate all of the replies and options. Now for me to dive in and see what I can do with it.

A decade or so ago, I was able to re-plumb a small house I had purchased to refurbish, largely due to the advice and expertise I received on this forum! The city inspector who inspected my work back then praised me for my work. But it wouldn't have been possible without this forum. Thank you to all!



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