: : It would not be my first choice and I have never installed 1 1/2" pipe for a drain even above the floor except as a short arm off the 2".

: : : I recently had a plumber cut the concrete in the basement to install a sink, disposal, and dish washer drain to connect to a sewage pit with an ejector pump.

: : : After the pipe was installed, I noticed that he had put in 1 1/2 pipe rather than 2 inch. He told me that the 1 1/2 was adequate for the 8 foot drain length.

: : : My understanding is that 2 inch is required under concrete by code.

: : : My real concern is if 1 1/2 inch will handle the load.

: : : Any advice?

:
: Thanks. I'm having him tear-out the 1 1/2 inch and put in 2 inch after talking to my local building inspector and after reading your message.

: Fortunately, I caught this before the concrete went back in.