More than 50% of the surface area of your slab is supported by only the ends of the flexible brackets. I know that they're strong, but that's a lot of weight and obviously they can bend. I'm not sure that the shims are really the main problem.... even if it was resting squarely on the kneewall, you'd still have more than half of your surface area hanging out in the air.
Angled blocks of wood or legs seems to be the solution. Whether it's up to the KD or the installer to make it right.... I'm not sure.

Stainless steel is softer than mild steel and so will bend easier.
But I think even a small gusset welded in at the bend would have solved the problem.

Looks like you have 4 brackets which are all flexing because I am not sure if these are the appropriate brackets to use!
To support 400 lbs of weight you will need brackets that have a web (vertical fin) to resist bending.
And are those dry wall screws in the brackets?

The entire design, engineering and installation needs to be reevaluated starting with the KD, then the installer.

It is too unsafe, in my opinion.

Besides the crashing soapstone that gap between the overhang peice and the backsplash would really bug me. However I don't think the shims are your major problem, it's the lever arm of the overhang.

I have a granite kitchen table extending out from a knee wall like you. The seam between the table and the backsplash is mitered. My table is 40-odd inches wide, I have two stainless steel legs (tablelegsonline.com) and I had a steel plate fabricated for support. So legs, then 3/4" plywood, then the granite. Overbuilt I'm sure but you could dance on it no problem. For you, those brackets look way under designed. I would recommend a plate resting on the knee wall & beefier, gusseted brackets. You could get the brackets power coated or chromed.

The posters that said the brackets are the problem are right. The L brackets offer no structural support at all. You need a much better support for your bar - one that would support the weight you put on it.

What is the length of the bar top? Your stone should weigh in the range of 20 lb/sq.ft, so it would be pretty easy to determine the weight of the piece.

If you want a "floating" appearance to your bar top, consider the following:

Attach a couple 2x4's (stood on end) to the top of your knee wall to support the stone. Fasten them securely to the studs. You can either wrap the wood with molding to accent or something else like drywall - primed and painted to match the wall. Either way you would not have a "knee knocker" and still retain the bracketless appearance you wanted while offering enough support for your bar top.

stonegirl - that looks great! If I understand correctly, you'd want to fasten two 2x4's for a total of 3" depth supporting the stone, by 3.5" height, cover with molding. Is the 3" (doubled up 2x stock) enough to support a 20" (in the middle) overhang of this stone?

I agree you should support the weight over the entire length of the wall, not just in a couple of spots. I would ask (since it's soapstone, should be easy to cut onsite) to have the backsplash cut even with the top of the wall while the upper counter is off so you don't have that gap - will help support the overhang even if you do what stonegirl suggested, and I'm assuming no molding will cover the joint on the lower side, so will look better there too.

I was wondering - since the lever action of the overhang is causing it to fall, something else you may want to consider to "counter-lever" (small cantilever) it is to pull off the backsplash, add brackets to the studs on that side, secure them to the upper countertop on the side overhanging the backsplash, then put the backsplash back on. I don't know how much room there is to work there, but if you could secure it on the other side of the fulcrum, it would help with the "teeter-totter" effect. Though ideally, you'd want equivalent force on either side of the pivot point, that would mean 20" overhang on each side ;-)

We only have laminate, but since my kneewall was built with studs spaced 16" apart starting from one end, not the middle, I only have 1 bracket with bottom screw in a stud. The brackets on either end only have the top screw going into the top 2x4. So my laminate guy built the counter with an "insert" of particleboard that goes over the end cabinets and was secured to the tops of the cabinets and the top of the kneewall. Then the U-shaped piece (9ft long x 42" wide at widest) was fit over the particleboard and secured from underneath the overhang and from inside the cabinets. I have roughly (didn't count) a dozen screws on the inside "ceilings" of my end cabinets, but that extra 2ft x 27.5" (overhang side of kneewall to point on angled front edge of cabinet) on each end of the 9ft length really helps counterbalance the 15" overhang on the other side of the kneewall.

{{!gwi}}

AJsMama -

On 3cm soapstone, the maximum unsupported overhang is 8"-10".

With an overhang of 1.5" on the kitchen side of the bar, the knee wall width of 6" and the 2x4 brace of 3" you are left with 9.5" of unsupported overhang on a 20" wide bar. That falls within acceptable parameters.

Thanks for clarifying that. I'd have to look at her other post, but I thought the unsupported overhang was 20" in the middle. But maybe it's 20" total incl. what's over the wall and backsplash. Hopefully the OP sees this.

Oops - just saw this from her original post.

"I posted a while back about what supports to use for my soapstone. I have a raised island with an overhang. The whole piece is 18" at the edges and arcing to 26" in the middle (the overhang is 12" arcing to 20" in the middle)."

So can't do that lovely "floating" edge with the crown molding (you'd have to use 9" thick instead of 3" thick brace, and it would severely cut into kneeroom at the ends where overhang is only 12").

Back to the drawing board!

(But stonegirl, I am putting this in my file for if we ever replace laminate with stone, we'll still have the cabinets on the ends but short of pulling off the drywall and adding studs to symmetrical locations, this seems like a really nice-looking and easier alternative to support the middle 5ft of our counter.)

Apologies - I have not read the original post and the pictures here are not very clear on the overall shape. That is a huge bar and a larger than normal overhang.

It is possible for the fabricator to add additional supports in the stone with a technique called "rodding". Slots are cut into the stone (on the underside!) and rectangular flat steel bar - i.e. 1/4"x1/2" - are imbedded (on end) in the stone with epoxy or acrylic stone glue*. These rods could still be added to your top. It would just mean the stone guys would have to come and take it off, do the procedure and re-install it. It is not something they really could do on-site.

The rodding should be done perpendicular to the knee wall and any support that you will be adding. It will not be enough to just have the rodding on a bar top of your size you really need to re-engineer that knee wall to add additional support. The current system you have in place offers no additional structural integrity.

You could use my original idea of the 2x4 on end, but increase the size of the lumber to 2x8 or such and add more than 2 or even 3 pieces, securely fastened to the knee wall and each other. You could wrap those with drywall or such and add a large corbel in the center if you wished. On a bar that size, knee space should not be a problem.

* The rodding should not be round or square, as this will offer no structural benefit. Placing the rectangular bars on end (I) will increase the integrity.

To prove this, take a popsicle stick. Hold it flat (--) and bend it. It bends and breaks real easy. Now hold it on end width wise (I) and try to bend it. Much more difficult! That is the science behind the rodding. Square or round bars will bend too, and that is why they are not advisable either.

I can't explain this well, but could they use a 1/4" (or whatever the backsplash gap is) steel plate attached to the knee wall to support the top?

Thank you all so much - I still don't know what I am going to do....

I measured the existing piece of soapstone:

1.75" overhang (left side of knee wall) + 4.6875 over knee wall + 11.9375 unsupported overhang (right side of knee wall) = 18.375" total length of slab at ends

1.75" overhang (left side of knee wall) + 4.6875" over knee wall + 19.875" unsupported overhang (right side of knee wall) = 26.3125" total length of slab in middle of arc

My KD spoke with the fabricator/installer. They suggest cutting the backsplash so it is the same height as the knee wall. Then to cut the stone so that the total dimension of the stone is 18" on both ends arcing to 20" in the middle. This would leave a maximum length of unsupported soapstone at the middle of the arc 13.5625" and unsupported overhang at each end of 11.9375" .

What do you all think?

Then the question becomes, what do I use to support the overhang? I am guessing I can't use the same brackets as before since they have bent a little. I am going to ask the fabricator what supports to use.

Part of my dismay is that when the templater was here I asked him if this part of the countertop was too big to be supported and he said no. Then when I called them while I was at the steel fabricator and was told that the top piece weighed 250 lbs and gave that information to the steel fabricator. Now it turns out that the piece was 400 pounds so I had bad information to give the steel fabricator. So now I am out $680 for the stainless steel brackets.

I don't know what the industry standard is, but shouldn't the stone fabricator/installer provide some guidance to a consumer regarding supporting their product? I am no expert and have no idea of what would support the stone. Based on the 250 pound information, I am guessing that the brackets would have held (and if the backspalsh would have been cut the same height as the knee wall so the knee wall could have lent some support to the stone).

I have to call the fabricator/installer and see when they can come get the stone to cut it (if this is what I decide to do). My floors are being refinished on Tuesday and we can't have the countertop supported by braces on the floor.

Then I am going to have to pay for them to come to the house, take the stone, cut it, and bring it back. And in addition to the money I am out for the stainless steel supports, I lose an additional $1000 for the part of the soapstone that will be cut off.... My DH is NOT happy (nor am I).

This is such a mess.

Thanks in advance!!

The fabricator (and template guy) should have advised you regarding the maximum allowable unsupported overhang for the stone. Because there is a KD involved, they might have discussed it with him/her.

Unfortunately design ideas are not always practicable. The idea of a "floating" top with no visible support is just not do-able for the bar top in your case. The stone is simply too wide for the available support.

The L bracket idea is one we come across often - and most often from the side of the designer. It is also the idea we talk our clients out of, exactly because of situations like yours. Even at 250lbs, the brackets might have held the stone, but what of the 20lb Thanksgiving turkey, or the 50 lb kid playing Tarzan (do they even do that any more?!) swinging from the bar top or the 120lb teenager that would decide to use the bar top as a seat?

In my opinion, you do not need to recut your bar top, but the knee wall needs to be re-engineered to suit the application. (See my suggestions in the posts above this one) Have a meeting with your KD, the stone guy, the GC and the carpenter and brainstorm. You might also hash out at that meeting exactly who will be financially responsible for whatever modifications need to be done to support the original design.

Some compromises need to be made: i.e. if you have your heart set on the "no visible support" idea, the bar is too big, or if you definitely want the big bar, you will have some form of visible support like corbels or the built-up top end of the knee wall.

Another thought that just occurred to me, is the fact that you have such a weight cantilevered on a freestanding knee wall. Did you make allowance for this, i.e. added additional bracing on the back side of the wall on the floor to accommodate the weight of the stone and to prevent the wall from moving at some stage?

One more option I could put out there: Make a "faux" table base with rails and two legs on the outside corners of the bar side. You will have adequate support for the overhang and a much more stable distribution of weight overall. It could also look quite attractive, but then again, it is quite a radical deviation from your original design idea.

Stonegirl I am so glad you responded....

If one of my kids would be playing Tarzan in would be my 3 year old DD. She is my daredevil. Granted I think she learned some of this from her 7 year old brother....

I can't begin to tell you how much this ordeal is taking out of me. I have ended up being more involved in our renovation than was planned and I am ready to scream.

I will check with the GC regarding the additional bracing on the back side of the wall on the floor to accommodate the weight of the stone and to prevent the wall from moving at some stage. My guess would be "no".

I am intrigued by your suggestion of the "faux" table base with rails and two legs on the outside corners of the bar sides. I am having a hard time visualizing this. Would I just put two legs, one on each end of the current 11.9375" unsupported overhang? Wouldn't I need something to support the middle of the arc? What rails would I use and where would they go? or would it be better to extend a wall from the knee wall on the two ends to support each of the 11.9375" unsupported overhang?

My challenge is that I realize this countertop is huge and am wondering if it would serve me better to keep the unsupported overhang on the edges as is and in the middle decrease the unsupported overhang to 13.5625" in the middle? I don't want the island and the overhang to overwhelm the room (which is what led me to the "L" bracket debacle in the first place). Then of course the question becomes, what do I get to support the overhang???

Thank you for your wise counsel!

I think many are overthinking the whole situation. As long as the wall is solid all you will need is supporting corbels that are weight bearing. The L brackets in the picture are just not cutting the weight of the stone.

Overhang on a bar top is different from an overhang on an island. The island would have more supported stone than a bar top. A bar top has more unsupported stone so simply put gravity will take over. In other words there is more stone on the overhang than on the supporting wall here. Gravity will always win in this situation.

Just put some weight bearing corbels on the knee wall and you will be fine. The soapstone in some way should have been bonded to the splash, which should have been bonded in some way to the counter below as well. . . There are L brackets that can be hidden behind the drywall as well. Just get the L brackets that are again. . .weight bearing. . .

I am learning gravity isn't my friend....

florida joshua -- Thanks for your input. I realize I am obsessing over this, but since I've already had a problem, I am trying to avoid more problems in the future (so I don't want to make the wrong decision).

When you say "weight bearing" L brackets, do you mean L brackets that are canitlever support brackets? I have found these and they don't seem as obtrusive as others I have found(they don't use a gusset - I think that is the term). According to the company, each bracket can support 1000 pounds....

Thanks for your help!

Here is a link that might be useful: possible brackets

Hi Joshua! How are you?

As for the legs and rails:

{{!gwi}}

The piece of wood connecting the table legs under the table top is the rail I was talking about.

You will have a 2 legged, 3 sided "table frame" connected to the knee wall, with the 3 rails supporting the bar overhang. You could offset the frame by say 3" or 4" from the sides, which would leave you with a 10" or 11" unsupported span at the apex of the curve. (If my math is correct... I am a little rusty)

I would do away with the brackets, since they are inadequate structurally, and put in some lengths of steel c-channel, bolted through the knee wall to the floor framing with threaded rod. The nut/bolt combo will pre-stress the knee wall, making it more sturdy, and the c-channel will carry the cantilever load of the stone.
It should be a 2.5 hour job.
Casey

Cutting off the stone would decrease the weight and move the center of mass more toward the wall. If you want to go that route, fine. It will make the problem a bit easier to solve.

From what I see here, there are too few supports for the size of the stone. I see here that they put them behind the drywall. This is good. I'm also going to guess that the weight of the stone is supported by the wall. The brackets are dealing with the torque, or twist, created by the fact that the center of weight is out over the floor.

If it were me, I would get plain black rolled steel brackets. The dark finish would look better than the stainless. They could be painted with some flat black Krylon or something similar. I would use one for each stud in the wall, not just 4. I would also have small triangular segments welded into the corner of the 'L' for support. The size of these triangles would be determined by the size of the molding I would use to cover them up.

When put pack against the studs and covered with drywall, no one will see them unless they go crawling around on the floor.

As the the knee wall, I assume the cabinets on the opposite side are attached to that wall. Their weight will hold the wall in place. For strength's sake, I would further attach the cabinets to the floor and back of the wall.

I think SG means to have two posts, one at each end. If the counter is stiff (it's rock), then it would not need any more support, though I would leave the 'L' brackets in place anyway.

Okay, I'm a little late to the dance, but we had something similar at my house. The soapstone guy said he was pretty sure our soapstone would be fine without any supports. Of course it's not his house and he's not an engineer. DH on the other hand lives here and makes his living by overthinkin' stuff--in other words, he IS an engineer.
He insisted that the soapstone would need corbels. So until we came up with something, he had pieces of lumber wedged under that stone to keep it properly supported.
I drew up this design & he cut it out of 2" thick cherry.

I looked at those brackets. They are almost ALL gusset, that is, there is a lot of material between the two 90deg surfaces to help with strength. It these don't bother you, then they would work much better than the brackets you have already. But you won't be able to hide the 'webbing' (the material between the two 90deg surfaces).

Deb's picture does not show any where near the overhang you have.

What about these "heavy steel" brackets?

Here is a link that might be useful: shortrunpro

Thanks to you all!

stonegirl -- Now I understand the legs and the rails, the picture helps!

sombreuil mongrel -- So I put the c-channel into the knee wall. I see how this would strengthen the knee wall, but how do I use it to cantilever the overhang? Do I attach something to the C-channel and then this will support the stone? I don't mean to be so dense - I must be missing something..

debsan -- Beautiful island and countertop. I don't think this work work for mine - I think I have too big of an overhang. Kudos to your DH, they are beautiful and strong.

weedmeister -- I am so gun-shy now about brackets without a gusset or supporting piece..... I didn't want to have that piece under the bar and have the kids knock into it (and the bar stools knock into it), but if I can be assured that the countertop won't fall onto the floor.... I am going to do a mock-up of the brackets with the gusset and see how it will look...

dtchgrl -- I am going to call them about these brackets since they look like what I had and didn't work. But if I reduce the overhang perhaps they will work. I need to find out what the weight capacity for each bracket is (if that is the right term - see how much weight each can hold). Then I would get more than I need to be safe.

I will use all of these options tomorrow when I speak with the fabricator/installer. You would think they would be able to suggest a bracket that will work (though as my DH reminds me, they were the ones who gave me the incorrect weight of the countertop to begin with........).

Here's what I am thinking of doing to my slab and the current dimensions:

Just as a word of warning, getting a weight rating for a support won't always give you as much info as you need. I'm not sure how technical to get in my explanation, but I'll give it a shot.

Think of your counter tops as your hand and forearm. Your elbow is the intersection between the knee-wall and the counter top. Keeping your upper arm down to your side, bend your left arm at the elbow such that your hand and forearm up are parallel to the floor.

Now take your right hand and press down on the fingertips of the left hand. Feel how difficult it is to keep your arm level. Now bring your right hand down about half way down your arm and press down the same way. You feel how much easier it is to keep your arm level this time?

That difference is known as torque or moment of force. You were applying pretty much the same downward force with your right hand in both locations, but it took a lot less effort to keep it level when you were pushing down closer to the elbow. That's because the rotational force caused by pushing down with your hand is multiplied by the distance from the pivot point (your elbow).

It's pretty much the same with your cabinets and supports. Your brackets are providing the upward force to keep the counters where they are. Gravity of course is providing the downward force. Your brackets may be able to support 250 pounds or even 500 pounds. If they're applying all of that upward force near the intersection though, and gravity is pushing the cabinets down along the entire depth of the overhang, the weight of the stone is multiplied by the distance the further it gets out.

All this is to say that simply finding a bracket that is rated to support X pounds won't necessarily solve your problem. Unless they're providing that support along the bottom of the counter (away from the intersection), you're going to have to get brackets rated significantly higher than the actual weight of the counter. I hope that makes sense and I haven't just confused things.

phil_va -- Thanks. I'm not confused, just worried... So then how the heck do I know what I need and what will hold the overhang? I am going to have it cut so there will be less to support. I hope this means it will be easier for me to find something to support the overhang. Do I need legs for this thing - even if it is just 14" of unsupported stone in the middle? At this point I wish I had gotten another surface for the raised bar portion of the counter. Is soapstone so much heavier than granite that this means this going to be impossible to do?

I am calling the fabricator/installer this morning and hope they can tell me what will support the overhang. If not, I am going to be really, really annoyed. And if they don't know I have no idea what I am going to do.....

Weight Bearing L Brackets. ..

http://www.shortrunpro.com/12x_12_granite_counter_top__bracket_lbrkt_357crs_54816_ps_vhv1700ytw_vhv17ytw.aspx

They are expensive, but they work. Many of my clients have used them in the past in similar situations.

It is not impossible. Cutting the stone back (if you want to) will make the job easier.

If you like the current size of the counter and it works for your kitchen design please don't be hasty in cutting it. There is certainly a solution out there for you.

Hi,
To clarify (hopefully) The c-channel cantilevers out from the knee wall. It is kept rigid and parallel to the floor by the "long bolts" (threaded rod) attaching it to the floor framing (or extra blocking installed between the floor joists).
Good luck. This was the only solution I could think of that would remain largely invisible. Unless the cantilever is pre-stressed to the floor, thus also strengthening the knee wall, the bending load will overtake the strength of any knee wall framed conventionally.
Casey

We are putting in soapstone and were told that unsupported, the max overhang would be 10" and after that you need more than just the steel brackets. . .I believe they wanted us to order cornices to place underneath.