Has anyone heard of this approach? Please advise.

Well, I've heard of supporting the overhangs with metal rods so I don't think your fabricator is out in left field or anything.

What I will say though is that our granite was installed last week. I have a 12" overhang that is 4 feet wide. The installer used some sort of board (it's not plywood, but close) to support the whole thing and I'm not at all worried about having an unsupported 12" overhang. The plywood (or whatever it is) underneath seems plenty strong enough, as long as no one does anything stupid like sitting on the overhang.

I saw this picture one time which I wanted to do, then decided not to worry about it. Maybe this would work for you:

I'm pretty sure that picture is of Cloud_swift's island. I was going to suggest her as a resource for what you want to do.

If she doesn't see your post, you can try emailing her through her MyPage linked below.

Here is a link that might be useful: Cloud Swift's MyPage

Thanks! This is the photo that I gave to my fabricator weeks ago. I just now found out they were using the metal rods imbedded into the granite. So you've heard of that approach. Do you think that is a safe approach for supporting a 15" overhang?

Other than this forum, does anyone know if there is any way to find out the industry standard or recommendations? I called my county regarding "code" and they didn't have any for granite.

Has anyone else heard of these metal rods being used? the fabricator says it's like the rods they use when concrete is poured. It helps hold it together. However, they still say you wouldn't want anyone to sit on the granite. They don't recommend anything heavier than 20 lbs. Any thoughts.

It sounds like they are referring to rebar (reinforcing bar) and it comes in #4, #5 & #6 commonly in concrete construction. #4 bar is 1/2" round. I have not heard of it being used for granite, but it might work fine. I say might because I don't have any experience with it. You should ask what size they are using and how close o.c. - on center. For # 4 bar, I wouldn't want it any further than say 12" apart. Is the bar being "embedded" into the plywood or?

Also, for standard structural, you want the bar to be 2 times the length of the overhang, sitting on top of your cabinets. So, for the 15" overhang, you should have 30" of bar set back over your cabinets - the bars should be 45" total. Its the 2/3 - 1/3 rule. Another question, how are they fastening the "embedded" steel to the cabinets?

One reason they may have chosen to use rebar is that it is readily accessible from almost any lumber yard and it is easily cut.

I think you need more answers before you let them proceed. Can they show you another job where they have used this process successfully? That might give you the confidence in them you need.

Here's a photo of what we did for our 21" overhang. My father welded up 1/2" steel tubing, routed into the cabinets and we screwed tabs to the other side of the cabinets. Since our slab was 1-1/4" thick we didn't have room or need for plywood subtops.

{{!gwi}}

This detail could be done with cut tube steel, angle brackets and drilled out and bolted connections also.

Good Luck!

You might ask on the forum on stoneadvice.com to get opinions from some granite fabricators. You haven't mentioned whether your counter top is 2 cm or 3 cm - that makes a difference to the unsupported overhang you can have and perhaps to the amount of reinforcement necessary for a larger overhang. Our granite is 2 cm and I would have been concerned that rodding it (which is what they call it when they route a channel and embed a bar) would weaken the granite by the amount of material removed.

I have heard of embedding L-stock or T-stock (a steel bar with an L or T cross section into an overhang for support). They put rebar in concrete to keep it in compression (which is where it is strong) and to keep it from falling apart. I would have two concerns about rebar, if that is what your fabricator is using. One - it usually isn't stainless steel - it can rust if exposed to water - not the best thing in a kitchen. Two - you need something very rigid to keep the granite from flexing - I don't think rebar provides that.

If it is threaded stainless steel rod, it might be a bit better but I'm still skeptical.

I think its flawed if they don't recommend there solution for anything heavier than 20 pounds. Don't put the turkey on the overhang? Don't let your friend who come over and are hanging out in the kitchen lean on it? 20 pounds is way to low for a reasonable limit to expect a counter to withstand. A hundred pounds might be more reasonable (i.e. don't let anyone sit or stand on the counter but you can put the groceries on it or lean on the counter).

Here is a link that might be useful: Stone Advice forum

Thanks for your responses. Mindimoo, your steel structure is awesome. No worry there. I wish I had researched this much better before having my kitchen demoed and ordering the granite. You both have some good points and good questions.

My granite is 3 cm. It is black (Labrador Angola) which I am told is the strongest of all granite because it is much less porous than the lighter colors. The steel rods are threaded and they are imbedded in the bottom of the granite, covered by epoxy. So, water isn't an issue. There are 5 rods total. I don't know what it's called or what size it is. Looked like 1/4 to 1/2 inch. They say it's made for granite and the concept is similiar to what is done with concrete. One rod is in front of the cooktop cutout. One on either side of the cooktop extending to the 13" overhang, and two on a diagonal to each corner on the other end of the island which is where the 15" overhang is. These two probably don't meet the 2/3 to 1/3 rule.

My original plan was to do something similar to the picture above in plywood. When I contacted my Lowe's cabinet installer to say I wanted to go back to Plan A he said it was overkill. He says he has demoed numerous kitchens where they had used the steel threaded rod and it is really difficult to break the granite. He was confident in their approach. I like and trust this guy but he is super busy so I hope he wasn't just telling me this because he didn't have time to help me prior to the install.

Anyway, the granite was installed today. The fabricator gave me a written warranty that it won't crack as long as we don't sit or stand on it. I still have mixed feelings about the support.

I still have the option of putting corbels on the end of the island although I wanted to avoid them because they are tough on the knees. But then again I wanted 15" there for the extra leg room since that is what many seemed to recommend on this forum. Also I could have L brackets on this end. There are doors on both sides of the island but the ends will just have panels (fake doors) which can be cut or notched for corbels or L brackets.

I'm thrilled that the granite is finally in. I've been 2 1/2 months without a sink. I don't want to regret not researching this more than I did or rushing into things. If only I knew about this forum sooner. The feedback has really been great! Please let me know what you think. Thanks again!

If I have L brackets put in by my cabinet guy now that the granite is in does anyone know how to attach it to the granite? Can it be done with some type of epoxy?

Your explanation of how they accomplished the installation sounds a lot better than I had originally thought. You still have 3/4" of stone over the embedded threaded steel rods (not rebar - thankfully)! That sounds substantial.

It is in and looks beautiful and you are happy, so don't unduly worry yourself -especially since they have given you a written warranty.

If you do decide to install the L brackets, find out what kind of adhesive your slab people used and use that, it would be the right type for your stone. It may be overkill, but if it keeps you from worrying about it all the time, it might be worthwhile.

Before you do that, have you checked yourself to see if there is a lot of flex in it?

I'm with you, not a huge fan of corbels and it's just such a clean modern look without them.

Post some pictures! We all love seeing new slabs!

Mindimoo, Thanks for your feedback. You bring up a good point about the adhesive for the granite. I bought some epoxy which is for marble, etc. but I need to remember that granite is porous and I need to be careful what I use. I'll contact the granite folks for advice. The L brackets I got at Lowes are the biggest they sell and can't be flexed easily. It will definitely give me peace of mind to have them installed on the end of the island with the 15 inch overhang. The 13 inch overhang still won't have any additional support other than the imbedded rods.

My granite fabricators were at the house Friday to measure and make the templates. My 57" x 68" island has a 12 inch overhang so they are planning to put 3 - 20" steel plates to the underside of the granite for reinforcement. They say they always reinforce any overhang more than 11". Here is a pic of the template they made.

on the L brackets...would it even be necessary for them to be attached to the granite IF attached to the cabinet? Why not just butted up tight to the granite?