What is the drain height for a kitchen sink?

[WorthFlorida]

I looked all over and I've read as low as 12" to high as 18" off the finish floor. The counter height is 36" the sink bowl will be 8 or 9 inches deep plus an in-sink-erator disposal. So what is the best height for the drain line coming out of the wall? Also, is the measurement to the center line of the pipe?

[jadnashua]

It depends on the model of the disposal. What you don't want is the connection in the wall to be higher than the outlet of the disposal...it must be lower so that after you make the connections, after the trap, it can still slope down to maintain flow properly. Too low would be more than 24" below the outlet of the disposal.

[Hackney plumbing]

I hit mine at 14" from the slab. Yes thats to the center.

[hj]

!2" will work, but it is a bit low. 18" would be tight for a deep sink. I do mine 14" -16" high. As a practical matter, it is almost impossible to install it too low, unless you get ridiculous and put it at the cabinet floor, but very easy to get it too high.

[jadnashua]

The arm from the trap must slope down. There's a limit on how high you can make the trap fit because from the outlet of the disposal, it must also slope down. So, the limiting thing is at what level the outlet of the disposal is. Then, consider you will eventually need to replace that thing, and the new one may be deeper/lower (as could be a remodel with a new, deeper sink). As said, you don't want it too high. Lower just ends up taking cabinet space, but constantly knocking the pipes probably isn't a good thing either. But, lower is easier to ensure you can install things properly, since gravity wins, you can make it work.

[Terry]

With the new stone counters and undemount sinks, I do 16" or lower.
I've seen way too many kitchen remodels where nobody called the plumbers in until they were done.
Old homes without disposers used to be at 21" and in the mid 70's it was 19" for a disposer.
With the new deep sinks, 16" would be the highest I would ever use.