Reposted from a 2011 thread:

"Hopefully this will help future readers looking for answers. The post by Buehl is all over the conditions of needing support as recommended by the MIA (Marble Institute of America).
This is for "Single-Level" counters with cantilever overhang:
For 3cm stone: any overhang over 10" will need additional support; spaced every 36" or less.
For 2cm stone: any overhang over 6" will need additional support; spaced every 24" or less.
For "single-level", the goal is to support the cantilever. We do this with CONCEALED SUPPORT. Single-level concealed supports use the mass of the supported material to "reach out" and support the un-supported material. "

I remember there were rules like any 3 cm stone with an overhang over 10" will need additional support. But how do you know it needs to be spaced every 36"? Doesn't that depend on what type of support you use?

Also, I am looking for recommendations for actual concealed brackets? Does anyone have any recos? or can someone provide a link to a thread about this? Many thanks!

We used the freedom brackets as well for our island. I think we used 3, plus we have the support on either end. Our island is about 11 ft. long.

Check with your granite installer if you have one. My island has corbels but the KD didn't include enough so the fabricator added a small bracket that you barely notice. It was $50 and they installed it with the countertop. The GC had to add a little support behind the decorative panel for them to nail it into.

My husband went to a metal store near us & basically fabricated our own support bar. The "T" was two separate pieces that he had welded together.

Edited to say that my husband told me "T" needs to be rotated 45deg counter clockwise. :-)

This post was edited by frugalnotstingy on Tue, Jun 4, 13 at 15:36

So after doing a bunch of further research, I realize the type of bracket you will buy will depend on the type of installation. For example, my granite is going to be installed partially on top of cabinets, so the bracket/brace will be attached to the cabinets. Whereas some people will attach it to a pony wall.

There were three concealed/hidden brackets recommended on this site.
1) Freedom Bracket by Federal Brace. One of the popular ones for islands/peninsulas with cabinets supporting part of the island. They recommend that you use one bracket no more than every 18" (starting 4" from the end), so I would need 7 brackets, right?

2) Counterbalance plates by Chemical Concepts. They actually recommended that I use two of the Counterbalance Crossbars. Not sure if that makes sense to me. I have to think that through more. Their supports are not suppose to be spaced more than 16" to 20".

3) StealthSpeedBrace. They recommend that I need the 24" brace (for a 15" overhang?) and to use 4 of them.

I'm going to do more research. I'll let you know what I end up with.

Yesterday I ordered the Freedom Bracket. I ordered the 12" x 12" length for the 15" overhang. And I ordered 6 six of them: two for the 39" side and 4 for the 72" side. Since I am in NY, they said that I should opt for normal shipping because it only takes two days to get there after they process the order (which takes 1-2 days).

Thanks for summing up the info!

I got a freedom bracket, too. I included the link where I got them below. It was super fast and when I needed help with the purchase they had good customer service. I have purchased from this company before with GREAT success so since they sold the supports, I got them there, too.

Here is a link that might be useful: freedom bracket - excellent service

Cabinet type plays a major role as well. Many of these brackets work fine for framed cabinets but not frameless. Design also plays a role in how that bracket will be secured to the cabinets.

I have a peninsula and frameless cabinets. I went with a brackets from amastin.com

Great info and exactly what I was looking for!

My granite installer was completely uninterested in how my 15" overhang would be supported - before and after installation. Do your research.

You might consider Fastcap's Stealth SpeedBrace. I haven't used it, but I've been keeping it in mind if I need to.

Andy.

Here is a link that might be useful: Fastcap Stealth SpeedBrace