Sloppy. And water can get under there and damage the cabinetry. I wouldn't want to have to accept that.

You can search the kitchen forum for all kinds of advice on attaching that sink properly (or edit and add the "kitchens" tag to your post).

Thank you so much Fori! I will come back to the company that did it and hopefully they will be responsive.

Good luck!

If they won't fix it I guess you just have to maintain the caulk really well? I don't know. It's not ideal.

I just realized I have that sink too! :)

That sink was in my house 1985--2000. I still have a horror of undermount sinks and hope never ever to own one again. To be the bearer of sad tidings---the caulk will look awful and the mold plus dirt will never go away.

Where did you buy the sink? It may have been slightly malformed......not completely level/true at all four corners. You may not have been informed of this, and it was simply "silicone and done".

In a rock hard mount of one rock hard, unbending surface to another rock hard unbending surface? Don't think it can't happen. I'm inclined to say that, before I blame the fabricator.......

As to under mount sinks? Beats the daylights out of the continual mess of a lip on the counter, yellowing caulk. Sorry, a simple swipe of an old toothbrush weekly, under the rim? No mold, no goo.

"Water can get under there and damage........"

Not likely. The sink has an overflow below that rim., and no way that's going to happen: ) Might you have to clean? Yes.

Take pics of all FOUR corners as you did the one corner.

Thank you Jan. We bought the sink from a reputed bathroom and design center in Ottawa, but they did not do the install. The install was done by the company that made the quartz countertop. The uneven sink rim possibility is interesting. I will go back to the bathroom and design center to ask about that. We had quite a few issues with the countertop company, so I was suspecting the sloppy install. I have an undermount in my kitchen, which we renovated 8 years ago, and we find it great (no gap, no goo).

" I still have a horror of undermount sinks and hope never ever to own one again. To be the bearer of sad tidings---the caulk will look awful and the mold plus dirt will never go away."

Rho:

You owned sinks that weren't properly undermounted. I've undermounted over a thousand sinks and not a single one leaks, looks awful, or has mold and dirt that never goes away.

sotheot:

It is a sloppy job and should not be that way. The sink needs to be dropped, the sink flange and stone bottom cleaned, and the sink reinstalled properly. I'd recommend a mechanical strap system such as the Hercules Universal Sink Harness or a Sink Strap.

IMHO: American Standard is an old company that makes excellent products. It's more likely the installation as mentioned above. I've had undermounts without these issues.

" I've undermounted over a thousand sinks and not a single one leaks, looks awful, or has mold and dirt "

Thanks for a personal response *~)

I was the 4th owner of a 11 year old house. Owner #3 didn't spend much time cleaning the house; to put it kindly.

Tjis is a mess but it sounds like the install company has already been a PITA to deal with so not sure if they will be the ones to fix this. All I can see is gunk getting in there all the time just a mess

My sink looks like that too :( It's got yellow streaks coming down in spots that don't come out no matter how much I scrub.

Well noted Skitt! Sorry for your sink, and thanks for sharing.

Thank you Joseph Corlett for your great suggestions, and all for your comments! It is very useful.

It's funny that someone apparently thinks water can only get places if the sink is stopped up and filled to that height. By that logic, mirrors never get splashed and we don't need shower curtains or doors. 🙄

@Fori - yes, that comment from Jan made no sense. And what about when cleaning the bathroom sink? When I clean my sink, I take the wet sponge all the way to the top and all around, and then thoroughly rinse. Am I supposed to not venture my sponge above overflow level haha?

Wait, @Miranda33, you're cleaning the caulk joint that people who don't like undermounted sinks because the caulk joint gets gross don't like?

Hehe now I shall slink off humiliated because cleaning didn't even occur to me. It certainly should have! :)