Undermount Sink Location

[Troy Ahner]

Coming to the end of my kitchen cabinet building and installation. I need some advise/experience for locating the undermount sink in relation to the cabinet and its cutout in relation to the countertop edge. (3cm granite or quartz)

The sink flanges are 19" (18" inside measurement). The clips for installing protrude 1-5/8 from the flanges. This adds up to 22-1/4". Face frame cabinet 3/4 plywood back, inside dimension is 22-1/2". Giving 1/8" per side from the clips.

With a 1-1/4" countertop overhang from the face frame and a 1/4" overhang over the sink, the front edge of the countertop will be 5" wide. (With the kitchen wall 3/8" out of plumb, the back edge ends up about 4-1/8" before the back splash).

Does 5" seem too wide for the front edge of the countertop? Is there a standard? Any good options for moving the sink closer to the edge?

Thank You - Troy

[Gary Ragatz]

We have an undermounted stainless steel sink with quartz countertop in the kitchen. The front part of the countertop is 4" which seems fine, but I don't know that 5" would be excessive. We have only about a 1/8" overhang inside the sink and the countertop overhangs the face frames by 1 1/2".

I didn't do the installation - this was new construction - but there don't appear to be any clips involved at all. The sink flanges seem to be attached to the quartz with some type of adhesive. There is silicone sealant on the inside of the sink where it meets the countertop, but I don't know that the sink is actually attached with silicone.

[Paul F Franklin]

4-4 1/2 is pretty common with stone; if it's much less it becomes a weak spot (well, weaker spot). But there are other considerations. How deep is the sink? The deeper it is the harder it will be to reach in over the front. And user height matters too. If users are taller, it's less of an issue, but if users are shorter, reaching in to the front of the sink will be a challenge, and you will find the front gets whacked when loading in larger items. Another consideration is the faucet. Some of them require a good 2 1/2 inches behind the faucet body for the handle or you will hit the backsplash with it. You should discuss with countertop fabricator, but keep in mind they might tend to recommend what is easy for them, not necessarily what is best for you.

[Troy Ahner]

Thank you for the replies.
The sink we are getting is a 9" deep dingle with the drain over to the left side. (Leaving us room for a trashcan and recycling pullout on the right.) Adding 1-1/4 for the countertop thickness the 9" sink is quite the change from our 6" deep top mount.
I have some melamine pieces in the garage, I think it would be worth the effort to mock it up full size and try it out.