We would like to use an undermount 9 inch sink in a new countertop. However this will mean that the bottom of garbage disposal drain pipe will be 1/2 of an inch below the top of the kitchen Drain Stub. Will this create any standing water? Will the drain be slow? Will it drain fine?



Edited 2 times.

IT depends on WHAT you are measuring, since the disposer drain is ALSO 1 1/2"

are you suggesting that you are going to create a deep trap? by code the trap seal is 2" min to 4" max unless you have approval first by the authority having jurisdiction.

there's a few solutions for your problem. Best one is to lower trap arm.

I hadn't measured the disposal pipe, you are correct it is 1.5", not 1.25". Therefore the bottom of the disposal pipe will be 1/2" below the top of the drain stub pipe.

No we do not plan to create a deep trap. The two pipes will overlap by 1/2 inch. We will not lower the drain stub. Is there anyway to connect this without sacrificing the speed of drain? The only alternative we have now is using a drop in sink vs. undermount which will prevent the two pipes from overlapping. We are getting ready to finalize the order for countertop.

Are you measuring from A or B? Is an 8" sink available?

Measuring from A,

An 8 inch sink not available