Disposal too low - drain repipe options

[ScottM]

My double bowl kitchen sink (remodel) has the common situation with the disposal is too low for my drain line. See photos. When running the disposal, water easily backs up into the other sink. Often dumping a large amount of water into the disposal side bowl has water backing into the other sink (like a slow drain). We've snaked the drain line and vent pipe from the roof, found no blockage and no improvement. I have opened the rear wall to evaluate repipe options and would appreciate feedback. We'd like to keep the disposal and have found no model with a high enough discharge.

Questions: 1) Do you suggest combining both bowls to a single trap and waste line uder the cabinet, and 2) Do you believe the current drain pipe has sufficient fall before reaching the vent?

 

[Bman3]

My double bowl kitchen sink (remodel) has the common situation with the disposal is too low for my drain line. See photos. When running the disposal, water easily backs up into the other sink. Often dumping a large amount of water into the disposal side bowl has water backing into the other sink (like a slow drain). We've snaked the drain line and vent pipe from the roof, found no blockage and no improvement. I have opened the rear wall to evaluate repipe options and would appreciate feedback. We'd like to keep the disposal and have found no model with a high enough discharge.

Questions: 1) Do you suggest combining both bowls to a single trap and waste line uder the cabinet, and 2) Do you believe the current drain pipe has sufficient fall before reaching the vent?

I had a similar situation in my kitchen. To get the disposal to drain it's outlet has to be higher than the drain inlet on the wall. Nothing you did not know. It is hard to tell if there is sufficient fall. In the picture your disposal drain looks hidden.

One option if the distance is close is adding a layer of plywood to the counter top. I have the largest disposal model that Insinkerator makes and with plywood, I was able to raise the disposal outlet 3./8 of an inch.

Here is a picture of my setup.

 

[Sponsor]

 

[Breplum]

You need a plumber to lower the actual drain or just delete the disposal.