New Sink Garbage Disposal P Trap Issue

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RichG

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I'm in the process of installing a new sink which has deeper basins than the previous sink. Because the basins are deeper the garbage disposal's outlet now sits lower than the outlet pipe into the wall.

My questions are:
1. Is it ok if the disposal outlet is lower than the wall outlet? If not, will I have to tear into the wall to mount a new outlet pipe?

2. If it is ok to leave as is, I'm having trouble finding a set of PVC slip fit pipes that will work. The standard 1-1/2" P Trap kit I picked up has a wall pipe with about a 1" extension to the flange off the bend. I really need something that extends down about 4" off the wall pipe. Does something like this exist? I've been searching around but can't seem to find anything. If it doesn't exist, does someone have any recommendations on what to use?

SinkTrap.jpg
 
No, that is not something that should be hooked up and left like that. Drainage water will sit inside of the disposal and smell to high heaven. Not to mention that it will rust the disposal out rather quickly.

You will need to get inside the wall to lower the drain pipe to do this correctly.
 
You may have another option --- going with a low / high sink ( one side shallow the other side is deep). The disposal might work on the shallow sink side.
 
It looks like it is on the high side. To the left of the disposal is a basket strainer that appears to be very close to the waste line height. As fish said it's time to open up the wall.

John
 
Good eyes John , I totally miss that.
 
I ended up calling a plumber. He ran a new line through the bottom of the cabinet and tied it into the old line in the basement. Here's a pic of the finished work:

FixedPlumbing.JPG
 
That is totally wrong. He is trying to use the old line as the vent. There are two things wrong with that.
1- He has a horizontal vent below the flood rim of the fixture.
2- If the waste line should become plugged below the DBL san. Tee It will run into the line that has become the new vent.
The correct way was to connect the new waste line to the vertical line in the wall.

John
 
johnjh2o said:
That is totally wrong. He is trying to use the old line as the vent. There are two things wrong with that.
1- He has a horizontal vent below the flood rim of the fixture.
2- If the waste line should become plugged below the DBL san. Tee It will run into the line that has become the new vent.
The correct way was to connect the new waste line to the vertical line in the wall.

John

If he would have put a c.o on the flat vent then in my area that would be considered right however there's no c.o so yeah if it backs up it could plug itself off. I agree that the the best would've been to go in the wall and lower it but depending on the circumstances of how easy it is to get into the wall. He did cap off the old line right? Otherwise if it rains you may have some water coming in through the vent.
 
If he would have put a c.o on the flat vent then in my area that would be considered right however there's no c.o so yeah if it backs up it could plug itself off. I agree that the the best would've been to go in the wall and lower it but depending on the circumstances of how easy it is to get into the wall. He did cap off the old line right? Otherwise if it rains you may have some water coming in through the vent.

I'm betting he did nothing with the old line and just cut a tee into the line in the basement and ran it up through the floor.

John
 
Without an airgap on the sink, the dishwasher discharge should be looped higher than the connection to the disposal so that water and food-gunk doesn't flow back into the dishwasher.
 

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