Yes, you need extra support for all of those scenarios. If your KD is designing the kitchen, they should be working with you to design the support from the beginning, as the cabinets themselves have to be strong enough to correctly transfer the weight all the way to the ground. If you are retrofitting stone to an existing kitchen, it's all on you to accomplish. A local metal fabrication shop can provide steel, or you can purchase one of the commercially available solutions like the Counterbalance system. Because it's a matter of aesthetics as well as engineering, it has to be on you as to which support will satisfy your desire for looks.

I plan to ask the involved parties about this today. For me, it's been a matter of everyone pointing in the direction of everyone else. In searching the usual kitchen and hardware sites, this company kept coming up (link below). I am going to ask about using one of the Hidden Countertop Supports.

It looks like you can order direct from them, but I found them on kitchensource or hardware hut or the like. Assuming that this is on me, once I decide on a style, I'll google away.

Here is a link that might be useful: Federal Brace

I ordered mine from Braxton Bragg.

Here is a link that might be useful: Braxton Bragg

I ran into the same situation with everyone pointing at someone else while insisting support wasn't needed. I finally did my research myself, ordered metal brackets and had the contractor install them before the stone was delivered.

Jams:

How about a drawing?

Treb...I'll take you up on that! I'd be grateful for any guidance you can give.

I had planned on a 15" overhang to sit at the end. I realized that most stools are wider than that at the base, so I'd rather go with 18" I've tried a plan where it's up to 21", thinking I could put two stools under there, rather than 1. I don't know at what point an overhang becomes too deep for understated support.

Also, at 30"w for the island, how many supports would you need across?

Thanks!

Our supports were supplied and installed by the granite guys. Discussion of what we wanted in the way of supports was part of the original conversation at the point we were filling out paperwork and handing over a deposit. It just makes sense, doesn't it? They charged us $49 each for 3 flat bars installed, but that was almost 3 years ago.

I bought steel strips directly from a steel distributor, and my contractor fit them into grooves he created in the plywood support. The contractor specified the length. We used 3/8" thick x 2" wide strips, which is a common size. The steel shop cut long strips of this size to the lengths I needed. The material cost about $50

Screw and countersink a 1/4" x 24" x 45" piece of flat steel painted black with 15" of the length cantilevering over the end of the cabinets. Pin 1/4" moulding to match the cabinets around the perimeter to compensate for and conceal the steel thickness. You can put a 21" overhang on that with no problems.

Thank you everyone for your answers. It seems like if I'm lucky the granite or GC helps with this, however i still need to source it out.

Here's a picture of what I'm working with. Currently I have 12" overhangs on 2 sides. I was hoping to get at least one of them to be 15" since DH is 6'2". However, he's the only tall one, the rest of the family and most of the extended family are relatively short (under 5'8"). Don't know how tall the children will be but they're still small and by the time they grow they'll have gotten used to it.

Where would you put these I-braces since I would like cabinets on the overhang side? Sorry trebuchet, you need to speak in laymen terms for me to understand.

Thanks
Jams

jams- we used wood corbels on our wainscoting for our smaller overhang. We picked them out for size and our carpenter supplied them. Our friend used massive wood corbels for her substantial overhang. Functions well and looks amazing.

Musicgal, your kitchen looks lovely. I like your intricate yet small corbels. When I think corbel, I think of those massive ornate ones. So if I do corbels, or the I-brace I probably need to shrink my cabinets on the backside and put some kind of plain post in between them so the corbels or braces attach in those position?!

Thanks Trebruchet! That sounds beefy. I suppose I find a local metal working shop for that. If they're as busy as the local counter and tile guys, it's not going to be pretty. I'd hope the granite guy has that contact, but I'm not overly confident. I also may check into alternate fabricators.

Would the tab-type work?
Braxton-Bragg I-brace 20 says it works for 12-22" overhangs, but is only 3/16". They suggest 16-32" apart (I think). 3/16" sounds slight.

Federal Liberty is 3/8" for 14-18" (support is 4 1/8" longer). More expensive, but definitely sounds beefier and safer. They suggest no more than 18" apart.

Would you think 2 or 3 of those would work? I'd really like to go 19" overhang now that the island is set. 16" depth Liberty supports?

I'll see about a metal shop, but I'd like to have an off-the-shelf solution in the wings. Thanks again.

Jams, cal_quail, This issue came up in an earlier thread. It has pictures of a couple of options installed. Hth!

Cal, are you planning two stools side by side in a 30' space? I think that will be a tight squeeze. 24' is the NKBA reccomendation for space around one stool.

Here is a link that might be useful: Steel supports

Vinudev, thanks for the link. Those pictures really helped me understand it better. So my next question, when you notch out the top of the cabinet for the brace, doesn't it impact the door of the cabinet too?

My fabricator did not consider support his problem at all. Many people DIYing IKEA kitchens have posted the same - that the cabinet maker is expect to provide the support.

"My fabricator did not consider support his problem at all."

This is just irresponsible, but not surprising in this "plop and run" lowest-price industry.

Our GC did the granite support as part of the cabinet installation. It was done in consultation with the fabricator to make sure the fabricator considered the support acceptable.

We have a 15" overhang in 2 cm granite. It is supported by a plywood underlay with steel bars inset into the plywood. We have frameless cabinets with doors opening under the overhang and wanted a support that didn't interfere with the doors or knee area.

There is about 1 bar every 2' but they angle to avoid the sink and range top areas.

jams- yes, for the corbels to be weight sustaining, they need to be substantially made and attached structurally to something solid in your cabinetry. My friend's overhang covers our laps when we sit at her counter, but her corbels are massive... also attached to her wainscoting and I suspect they may actually cover a metal brace. Wish I had a picture, but in her house- that counter area really is a star in the show, since the home is modestly sized and that feature really shines without overwhelming the space.
Our top bar rests mainly on the center wall, but it is so high I wanted the underpinnings to have some style. Our granite folks made sure even our little overhang was going to be supported. They would have supplied something if we hadn't, but we'd picked them out beforehand. Thanks for the good words.

jams- yes, for the corbels to be weight sustaining, they need to be substantially made and attached structurally to something solid in your cabinetry. My friend's overhang covers our laps when we sit at her counter, but her corbels are massive... also attached to her wainscoting and I suspect they may actually cover a metal brace. Wish I had a picture, but in her house- that counter area really is a star in the show, since the home is modestly sized and that feature really shines without overwhelming the space.
Our top bar rests mainly on the center wall, but it is so high I wanted the underpinnings to have some style. Our granite folks made sure even our little overhang was going to be supported. They would have supplied something if we hadn't, but we'd picked them out beforehand. Thanks for the good words.

Vinydev_liny - The plan was for one in 15" x 30+". Then I looked and saw that most barstools have a base wider than 15, so I'd think the legs sticking out would be dangerous, so I am going to try for 19". I think one will still stay under it, but I can see perching for 2 happening occasionally. IF I can find somewhere to keep a second stool nearby.

As we've been working on the kitchen, we've put a stool in the place where we used to have our trash can. We're so used to something being on that wall, it has just felt natural. But the stool is too big. I thought I might look for a narrow stool to keep there. But more likely I'll find a stool that I can put in the corner of the dining room and maybe use it as a plant stand when not in use in the kitchen. Something like that.

"yes, for the corbels to be weight sustaining, they need to be substantially made and attached structurally to something solid in your cabinetry."

Correct. If your corbels are pinned or finish nailed only, they aren't doing much work.

Our fabricator would not proceed with a 15" overhang (quartz) without a steel frame for support. Period.

My KD and cabinet guys all felt it was overkill, steel bars should be OK for up to about 15" - but I really - REALLY - like this fabricator and I didn't feel he was trying to oversell me - just being extra cautious.

cloud_swift:

Nothing personal, but there are several things about your underlayment I don't like. First, the plywood looks like cheap C/D which doesn't lay or stay very flat. Secondly, long sections of 1/4" steel have little strength in tension without triangulation. I doubt the steel even compensated for the plywood they removed to bed it. They should have embedded Unistrut if that's the way they were going to go.

This post was edited by Trebruchet on Mon, Jul 28, 14 at 20:57

Jams, here is the underside of my 18'' overhang. As you can see my cabinetmaker (answer to one question) put in a 1/4'' rolled steel plate under the granite. It is 96'' in width by 48'' in depth to meet the magical 2/3s cantilevered spec (14.5'' under the overhang, the remaining 33.5'' under the rest of the granite on top of the island). Our steel only cost $179 and for the peace of mind it is downright cheap. I hope you are able to get the help you need in coming to the best solution.

Thank you to all of you for your help and those photos. I think I see the light...but I still have questions.

If I want a 12" overhang, 2cm granite, I need to have 6" of support under my overhang and 12" under the rest of my granite.

If I want a15" overhang, 2cm granite, I need 9" of support and 18" under the rest of my granite.

If I want 12" OH, 3cm granite, then it's 2" support and 4" under the rest and if it's 15" OH, 3cm granite, then it's 5" of support and 10" under the rest.

If I did the rolled steel, would it make a big difference if I had a sink cutout on the other side? I plan for a 15" deep cabinet along the backside, so in the situation where I need 18" under the rest of my granite, could I eliminate the 3" under that section, or cheat and just cover the 15" cabinet? And do you just screw this into the cabinets along the top edges? And how often do you add a screw? One every 12"? Do you also add glue?

How am I suppose to balance out the 1/4" difference from the front of the island to the back? And once balanced, do I still need a plywood underlay? Who normally supplies the underlay? Is it only for counters who are 2cm thick?

Sorry for all the questions. This is my first reno and I'm not reno savvy. The most I've done is paint and build a few ikea shelves.

Sum5463, it looks like your steel ends in the middle of the cabinet closest to us. How did you balance out the difference?

Again, a big thanks to you and your photos.

Jams

jams:

It sounds like you're smart enough to know what you don't know. This is the most important thing to acknowledge for a successful remodel and life in general.

Rather than answer a ton of technical how-to's, I think you would be better off hiring competent help. Find someone capable of adhering to the MIA standards for overhang support:

Here is a link that might be useful: MIA

Trebuchet, I never said the steel was 1/4". It was thicker than that. 3/8 or 1/2". I tried putting my weight on it before the granite was in and couldn't get it to deflect at all.

The overhang has survived one of my sons standing on it to clean the ceiling when a soda bottle exploded. (Not something I would have allowed, but he was up there before I could stop him.)

Jams, most fabricators put plywood underlays under 2 cm granite and not under 3 cm. If the 2 cm granite has a laminated edge, that covers the edge of the plywood. Friends who used 2 cm without a laminated edge put a bit of molding over the plywood edge. Other friends just left the plywood edge uncovered - it is hidden by the shadow of the granite between the granite and the cabinet and they don't have an overhang so you really can't see it, but having the unfinished bit of plywood uncovered would bother me.

If a metal plate isn't inset into plywood or the cabinet top, the rest of the cabinets would have to be shimmed to make the granite level.

After the kitchen was done, I realized there was unfinished plywood on the underside of the overhang. No one but a toddler or someone sitting on the floor would have noticed it, but it bothered me. I'd have asked them to use plywood with a veneer to match our cabinets if I'd thought about it ahead of time. My DH has since skinned the bottom with a veneer so that's fixed now.

cloud_swift, thanks for pointing out that the plywood will be exposed on the underside of the overhang (presumably). I hadn't thought about that. I'll look into skinning it with something. Thanks!!! That will be visible from the living room, probably.

For that reason, we're also going to go with corbels. I think. Whether we went with a steel plate or the strap hidden brackets, I don't think I'd be happy. Corbels aren't my first choice in most applications, but I think it will be best here, for me.

Cal Quail, If the steel is inset into the plywood, you won't see it.

Even if there is no plywood, you won't see the bottom of a counter height overhang from sitting or standing in the living room unless perhaps the living room floor is lower than the kitchen floor. I just double checked that sitting in my family room and I don't see under the overhang.

Plywood sheets can be bought with veneer on one side. It adds slightly to the cost but not much. I think that is more convenient then skinning after the fact and it may be more durable though the underside of the overhang shouldn't get much contact.