I'm installing a kitchen sink, and I'm wondering how high up the wall from the floor the drain pipe should exit the wall... Seems like about 20 inches is correct, but is there a standard for this?
That depends if there will be a disposal unit under the sink or not, the depth of the sink itself, and if it is under-mount or over-mount (under or over the countertop).
20" is a bit too high for my comfort.
I would think 16" would be better...but am not sure...
Traditionally, a kitchen sink is 36" high....on average, people are taller now so I'm starting to see heights creep up.
In our bathroom, vanity's are at 34" vs the typical 32" or 30".
In the kitchen...make sure you take into account the depth of the sink...sinks are getting deeper....and if it's under mount of drop in...(makes about 1" difference).
Personally...if you can make 20" work...go with it....it gives you a bit more room under the drain for more junk....and a bucket for when you have to remove the P-trap