What is the drain height for a kitchen sink?

Users who are viewing this thread

WorthFlorida

Clinical Trail on a Cancer Drug Started 1/31/24. ☹
Messages
5,727
Solutions
1
Reaction score
982
Points
113
Location
Orlando, Florida
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

Retired Defense Industry Engineer xxx
Messages
32,770
Reaction score
1,190
Points
113
Location
New England
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.
 

hj

Master Plumber
Messages
33,602
Reaction score
1,041
Points
113
Location
Cave Creek, Arizona
Website
www.terrylove.com
12" 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

Retired Defense Industry Engineer xxx
Messages
32,770
Reaction score
1,190
Points
113
Location
New England
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

The Plumbing Wizard
Staff member
Messages
29,942
Reaction score
3,459
Points
113
Location
Bothell, Washington
Website
terrylove.com
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.
 

Tuttles Revenge

In the Trades
Messages
4,132
Reaction score
1,410
Points
113
I always measure from the top down for sink heights. If your typical cabinet starts at 34.5" but depends on if its sitting on the finished floor or rough. Undermount sink drops 10" to the underside. Disposal with a continuous waste adds 7-9" (9 gives some wiggle room and you don't have to cut the continuous waste). That puts my typical kitchen sink stub out at 15.

The contractor I work with the most uses roll out shelves under most of their sinks, so just going low isn't an option.
 

WelATX

New Member
Messages
3
Reaction score
1
Points
1
Location
Austin, TX
I measured the center of my wall drain stub out at 20.5" down from the top of the base cabinet.

I'd like to go with a 10" deep undermount stainless steel sink. The spec for the garbage disposal (Insinkerator Evolution Septic Assist) says the center of its drain is at 7 3/16" (6 11/16" + 1/2") so once mounted the disposal drain center will be at 17 3/16" down from the top of the base cabinet.

That leaves the disposal drain center 3 5/16" higher than the wall drain center. Will that work in terms of getting the P-trap hooked up? (my assumption is that small distances might be hard/impossible to offset due to minimum size of certain fittings).

The sink has a right offset drain (see picture below) so the pipe from the disposal will also need to move leftwards towards the center (where the wall drain is).

Thanks for any advice!

welatx-01.jpg


welatx-02.jpg
 
Last edited by a moderator:

Tuttles Revenge

In the Trades
Messages
4,132
Reaction score
1,410
Points
113
So yeah.. 20.5" from the 34.5" tall cabinet should put your at 14 above finished floor. That just barely hooks up without extending or cutting the drain pieces.

With a drain so close to the rear of the sink, I like to have my drain stubbed out of the wall just about 6" left of center so that the disposer outlet faces about 10 oclock looking down. Fitting the trap is easier because the drain parts are visible, but still tucked out of the way to keep space clear in your cabinet. If you're using the drain of the disposer for the dishwasher air gap, then also consider that the drain hose needs some slope/radius from the air gap to keep from kinking.. having the air gap mounted to the left of the faucet would allow for a nice gentle arc of that rubber hose.

**Why did I dredge up this 2012 topic?**
 

WelATX

New Member
Messages
3
Reaction score
1
Points
1
Location
Austin, TX
Cabinets are 34.5" high before the counter is installed, so your drain must be 14" from the floor. That works well with 10" deep sinks that have disposers.
My cabinets are 35.5" high off the concrete slab and the drain center is 15" from the slab. Once the 1/2" hardwood floor and 3cm countertop is added the countertop will be 36.18" off the finished floor. In any case, I'm assuming the plumbing situation is identical to a 34.5"/14" scenario since the height between the drain center and the countertop is the same (20.5").
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks