Undermount Sink - Secure?

[DMannis]

Hello everyone!

I have an undermount stainless steel sink installed in my marble countertop. This sink has been getting a lot of use lately, with heavy pans / dishes and water (someone who cooks a lot just moved in with me). I'm wondering how secure I can expect this installation to be? The sink is held by four screws that were drilled into the underside of the marble (two on each side of the sink). Two pictures are below - one of the sink from the top, and one showing the screws underneath. Is this a secure method of installation? For what it's worth, I noticed there is some slight movement in the front, brass-colored bracket if I touch it (I can jiggle it back and forth a little), but the screw set inside the bracket is tight. The other 3 brackets and screws all seem secure. Thanks for any thoughts or peace of mind!

 

[Terry]

I sometimes see wood blocking also installed for undermounts.
And I've seen a few undermounts falling down over the years.
You might want to snug what you have there, and perhaps look at more bracing.

 

[Sponsor]

 

[DMannis]

Hi Terry,

First, thanks for taking the time to reply! Looks like you have a great wealth of information on here and I appreciate benefiting from your expertise. As for your response re: my sink - I was able to tighten all four of the screws a bit and now the brackets are very secure and have no movement. Is there a reason they wouldn't have been tightened all the way at installation (is it bad for the stone if they are too tight?), or did they likely just loosen over the 2.5 years since install?

Adding additional reinforcements would probably be beyond my (very limited) DIY skills, so I'd have to bring someone in - would you recommend doing that? Does this look like insufficient support for a sink of this size? For good measure I've attached a photo of the other side of the sink. Thanks again!

 

[Tuttles Revenge]

I just did a google search for "undermount sink brackets" and found several versions of what I see in the field a lot these days.

https://blades.caimanstore.com/undermount-sink-bracket-accessories-safety/

Another version of the same

https://nativetrailshome.com/product/sink-undermount-kit/

I wouldn't drill up into the countertop like the original installers did just because you're more likely to drill thru the top or break a chunk off.