Could this granite crack?

[Kerry Adams]

Good Morning,

Neighbors had Home Depot put in cabinets and granite. Granite sits on cabinets and hangs over 10 inches, with no support. It runs like this for six feet, and is a sit at bar. No knee wall and back of cabinets are covered with a sheet of laminate. Any installers here?

Thanks,
Kerry

[Ray Dockrey]

I found this on a place that does granite countertops:

I intend to extend my new granite countertop beyond the cabinet base. How far can I extend it without adding support?

The maximum extension is two fold:

It cannot extend more 1/3 the width of the countertop without suport.

In any instance it cannot be extended more than 10 inches regardless of the width without additional support.

It also said that the maximum span between cabinets is thirty inches.

[Steve Clardy]

10" is fine

[Sonny Edmonds]

Granite being a natural stone material can have stability issues. It's a very hard thing to call, whether it might break or not.

I've done a couple of cabinet jobs and always tried to make sure I had a good underlayment of plywood (luan). The ply was called 3/4", but it was more like 5/8" actually.
We put bull nosed granite on these, so the underlayment was hidden anyway, and I had the confidence of doing what I could to support the stone well.
My eldest Sister asked me about her island/breakfast bar they were going to have installed (extensive overhang), and I advised her to make sure there was a good underlayment of plywood to help support the stone.

I had one measurer tell me they would have to put underlayment on my set of cabinets to make it level. I stepped to the shop and returned with a 6' spirit level and showed him there wasn't a single square inch that wasn't level in any direction. Absolutely plumb!
That company eventually lost the counter top job, the store manager refunded our money (including the measuring fee), and we bought granite at another store that same evening.

Anyway, I think the underlayment is a key item in supporting the stone

[Belinda Barfield]

10" overhang is probably okay. Having said that, one concern would be if there children/teens/adults in the home who are likely to jump up on the countertop and sit on the overhang side. It's not an issue of cracking or breaking the granite, but if the top was not properly installed it could potentially flip with weight on the overhang. This should not be a problem with every day use.

[Cliff Rohrabacher]

That all depends on the stone.
All Granite is not Granite. Most the stuff sold for counter tops is not granite.

I recently did a kitchen using a product called "Absolute Black Granite" It isn't granite but. it is dense - prolly the densest stone you can get. It's some beastly hard rock from India. But it is not Granite.

If the stone you have is highly figured then you are at risk.
If the stone is made of large flakes that glint prettily then you are at risk.

Etc. The smaller the grains and the more densely packed they are, the tougher the stone is.

Every stone will be different.

[Kerry Adams]

Thanks Cliff-- thats what I think-it is the pieces that glint at you . It just doesn't look like granite to me. I guess we will wait and see.

Thanks,
Kerry

[Belinda Barfield]

I recently did a kitchen using a product called "Absolute Black Granite" It isn't granite but. it is dense - prolly the densest stone you can get. It's some beastly hard rock from India. But it is not Granite.

If the stone you have is highly figured then you are at risk.
If the stone is made of large flakes that glint prettily then you are at risk.

Etc. The smaller the grains and the more densely packed they are, the tougher the stone is.

Every stone will be different.

Actually, what is known as Absolute Black granite is basalt. There are two varities, Absolute Black Z (Zimbabwe), and Absolute Black I (India). Many stones with a lot of movement are more at risk for breakage, but that is not true of all highly figured stones. One of the more stable is Galaxy Black - black with large copper and silver flakes that glint prettily. Some of the smaller grained stones can crumble like sand. One of the densest stones is soapstone, but it can have dry veins running through it that are high risk areas for breakage.

Yes, every stone will be different, even when split from the same block.