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isixpacku

18" granite overhang and everyone tells me I don't need supports

isixpacku
9 years ago

We had a meeting this afternoon with the fabricator for templating. We are going to have an 18" deep overhang at its deepest point as depicted below.

Because the granite slab will be supported on the sides by 12" deep cabinets, the fabricator, KD, and GC are telling me we don't need any kind of supports in between the 12" cabinets. I asked about the MIA standards and anything more than 10" deep need supports if the slab is 3 cm thick as in our case, and was told by the fabricator it only applies situations bar counter like situations. Is this correct?

Comments (34)

  • User
    9 years ago

    No, not correct.You need some steel.

  • isixpacku
    Original Author
    9 years ago

    Hollysprings - Do you know what I should specifically request? Are metal rods routed into granite or are L brackets the solution?

  • User
    9 years ago

    I'd do something like the Counterbalance brackets so it would be virtually invisible.

  • PRO
    Joseph Corlett, LLC
    9 years ago

    isixpacku:

    While rodding the top will make it much stronger for cantilevering, it does nothing to prevent tipping.

    You can have a professional installation for $50.00 worth of steel and less than an hour of time. Make 'em do it.

  • isixpacku
    Original Author
    9 years ago

    Hollysprings - I looked into the various counterbalance options last night but am having a hard time figuring out what will be the best option.

    Treb - What type of installation of steel should take place?

    The issue is that we have cabinets on the backside of the island as shown in the picture below. I think some modifications have to bee made to make any of the counterbalance supports work. Is there an easy solution?

    I am mostly just kicking myself for not making the kitchen designer incorporate supports into the plan. I brought it up several times during the design process and stated my concerns. She said not an issue every time and then she finally said that we will talk about it with the fabricator when they came out. Next time I am just going to listen to my instincts. It's hard when the people who are supposed to be the experts don't follow the standards.

  • feisty68
    9 years ago

    My fabricator stated that our 15" overhang (of 3 cm granite) didn't need any support. When pushed, he said that 6" brackets would prevent deflection if someone was putting excessive weight on the overhang. Our island is *very* well attached to the floor though, so I am not worried about tipping. I think the problem is that fabricators often consider it the cabinet maker's responsibility to provide support, but the cabinet maker isn't an expert on stone counters - that's what I've read in fora anyway.

  • PRO
    Granite City Services
    9 years ago

    I am a fabricator.

    You should have support. Given you have cabinets under the overhung area you'll want support which doesn't intrude into the area below the countertop.

    In this situation we would use 3 or 4 shallow steel supports (12 X 3 X 1/2" or something similar) and relieve (grind away) the underside of the stone so the supports are flush with the underside. The trick to this approach is that the cabinet structure must be strong enough to provide a rigid anchor point for the cantilevered support. this can be a challenge if the cabinets were not built with this requirement in mind.

    An alternative is to have a 3/16" steel plate cut that overlays the cabinet and underlies a significant fraction of the protruding countertop section.

    Good luck with your project. Looks like it'll be beautiful when done.

  • PRO
    Joseph Corlett, LLC
    9 years ago

    isixpacku:

    Have a piece of 1/4" thick steel plate custom cut to follow about 3" behind the front edge of your top and cover the tops of the 12" cabinets. Screw some blocking below the tops of the cabinets and in front of the rear cabinet wall and screw the steel to the blocking.

    It's fast, relatively cheap, and you'll know that stone is going nowhere, no matter what.

  • ajc71
    9 years ago

    "Have a piece of 1/4" thick steel plate custom cut to follow about 3" behind the front edge of your top and cover the tops of the 12" cabinets."

    And route into the cabinets or relieve the underside of the stone?

    Seems to me the easiest way to do it is to get a couple pieces of 1/4" X 3" X 15" steel plate, have the carpenter route a space for them that spans the top of the sides of the cabinet so that the weight is transferred through the cabinet to the floor and set the top

  • PRO
    Joseph Corlett, LLC
    9 years ago

    ajc71:

    Set the steel on top of the cabinets. The top will be a 1/4" higher than it otherwise would have been. Big deal.

  • suzanne_sl
    9 years ago

    This is what ours look like for our 14" overhang:


    The stone people provided and installed these supports. They routered a bit of the top of the cabinets so they would be flush, which didn't cause any problems with the cabinet tops. It just wasn't a big deal and didn't need to be planned ahead. I think this is a very typical support system.

  • PRO
    Joseph Corlett, LLC
    9 years ago

    suzannesl:

    Your support is minimal and looks to be spaced too far apart to meet MIA standards.

  • illinigirl
    9 years ago

    how far apart is the support supposed to be to meet the MIA standards?

  • ajc71
    9 years ago

    "Set the steel on top of the cabinets. The top will be a 1/4" higher than it otherwise would have been. Big deal."

    I guess the big deal would be that there is now a 1/4" gap between the cabinets and counter around the entire perimeter??

    "Your support is minimal and looks to be spaced too far apart to meet MIA standards."

    Looks like the brackets are spaced about 24" apart (if the veneer flitches are approx 8" wide) should they be closer then that?....and if she had a 14" overhang and these brackets stuck out 4" would that still count as a 10" unsupported overhang?

  • PRO
    Joseph Corlett, LLC
    9 years ago

    "I guess the big deal would be that there is now a 1/4" gap between the cabinets and counter around the entire perimeter??"

    ajc71:

    Cabinets. Full steel underlayment. Countertops. Where is this "gap"?

  • ajc71
    9 years ago

    "Cabinets. Full steel underlayment. Countertops. Where is this "gap"?

    I must be a little slow today (maybe most days actually)...the op has a slab top sitting on top of flush cabinets, seems as if you are suggesting that she gets a custom sized full steel underlayment to follow the curve of the top approx 3" back from the leading edge. With no lip on the counter, and the cabinets not routed to accept the steel it sure seems as if there will be a 1/4" gap (steel) showing between the cabinets and the underside of the counter

  • live_wire_oak
    9 years ago

    "With no lip on the counter, and the cabinets not routed to accept the steel it sure seems as if there will be a 1/4" gap (steel) showing between the cabinets and the underside of the counter"

    No, it's not a "gap". It's full of steel.Take a tape measure and see how small 1/4" actually is. Unless you are 3' tall, you'll never notice that steel under the counter. And a 6 year old child won't even notice it if you paint it to either match the main color in the granite.

  • ajc71
    9 years ago

    Little confused (still)...when Trebruchet said for $50 worth of steel and to make someone do it, I was not picturing a whole sheet of steel for this counter to sit on, especially with the top approx 60 X 118...

    On our frameless projects we set our reveals at 2MM on all of our cabinets, even between the bottom of the counter and top of door/drawer front...pretty sure someone would notice the additional 6MM gap (or gap full of steel)

  • Amy Sumner
    9 years ago

    Isix, we went the 1/4'' rolled steel route with our 18'' overhang. Love the support, the lack of posts/corbels, etc. It cost us $179 for 4' x 9' of steel. I finished all exposed steel with 4 coats of old fashioned shellac at my cabinet maker's suggestion. That way you don't get any of the raw steel schmutz on your clothes or hands if you reach under the overhang. Definitely recommend this solution to your concern. FYI, our steel was counter set into the cabinets, but even if it were not, as Treb and others said, it really doesn't show. Especially if you shellac it--turns glossy black and disappears. Picture shows the steel before the granite was installed.

  • User
    9 years ago

    What does the underside of your counters look like right now? When was the last time you were on your hands and knees looking up at it?

  • isixpacku
    Original Author
    9 years ago

    Thanks for the comments and suggestions everyone. This situation was stressing me out and I handed over the issue to my husband to solve with the suggestion of contacting Amastin and the main person at the fabricator to see if they recommended something different than the person who came to our house to measure. The fabricator still swore we didn't need any support and the KD said the same thing to my husband.

    My husband then contacted Amastin regarding our situation, sent them pictures and the cabinet drawing, and Stacy, the owner, proposed two custom support options for us to install on top of our cabinets. We picked his recommended option, and then Stacy speedily made the supports and got them ready for the last FedEx pick up of the day so that we would have the supports in time for the granite install. He provided top notch customer service.

    The cabinet maker, who is also our GC, is going to add some extra support to the underneath side of the top of the base cabinets and then route out part of the cabinets for the supports so that the granite can be installed flush with the rest of the cabinets. I will take pictures and post them after we return from being out of town.

    Thanks again for the suggestions.

  • ontariomom
    9 years ago

    sum5463,

    I don't suppose you have any more pictures that show the steel installed? I take it you have cabinets on the backside of the island (under the overhang) correct?

    OP, sounds like you have found a solution. I hope you will come back and post the pics as we will need to solve this puzzle soon too.

    Thanks,

    Carol

  • Amy Sumner
    9 years ago

    Carol/Ontario Mom, is this picture helpful to you? My island is basically 10x 6 and one side is all drawers. The other side with the 18'' overhang has 3 wide doors that open for off-season storage. The short ends also have cabinets (trash, recycling, reg storage on one end; linens on the other end). I can post/send you pictures of the steel in process if that is more what you are looking for. OP, forgive the hijack, please!

    Amy

  • ontariomom
    9 years ago

    Amy,

    That picture is exactly what I was looking for thanks so much! If you have anymore, please post or email me them please. Sorry for the likely stupid question, but where does one buy that kind of steel? What kind of shellac, and why exactly did you find the shellac necessary? It seems like the steel solution is better than corbels/brackets if you are trying to incorporate storage under the overhang as you have done.

    Your island, and what I can see of the kitchen, look great, Amy!

    Carol

  • Amy Sumner
    9 years ago

    Carol, I'll send you extra pix offline so as to not take over this thread. In the interest of sharing info, I can tell you that we (my cabinet maker) got the steel plate from a local steel fabricator. Most cities, even smaller cities, have these businesses. Re the shellac, again, my cabinet maker suggested it. Rolled steel that is left "raw" will rust over time. As you can see from my picture above it is exposed under the granite simply because it is what gives the additional support. If you did not put some coating on it you might end up with rust or that messy black dust on your clothes and hands. The shellac seals it and keeps everything/everyone clean. Why shellac and not polyurethane? I have no idea. I just followed my cabinet guy's direction. :)

  • PRO
    Joseph Corlett, LLC
    9 years ago

    Amy:

    Thanks for the picture. As long as that steel is 2/3's the depth of the cantilever, that's a properly supported granite overhang.

  • Amy Sumner
    9 years ago

    Treb,

    My steel plate is 48'' in depth by 102'' in length. 14.5'' of the 48'' is exposed, supporting the 18'' granite overhang. In case anyone is interested, the steel plate is screwed down into the base cabinets.

    Could you please clarify the 2/3 measurement? Does that mean 1/3 supports the overhang and 2/3 is under the rest of the slab? And what determines the measurements in this equation--the overhang, the total slab size or the base cabinetry? I so appreciate the knowledge and expertise in this forum!

    Amy

  • PRO
    Joseph Corlett, LLC
    9 years ago

    " Does that mean 1/3 supports the overhang and 2/3 is under the rest of the slab?"

    Amy:

    Yes. This is a minimum. The cantilever makes the numbers. If you want to cantilever 15", you need a 45" piece of steel minimum.

  • isixpacku
    Original Author
    9 years ago

    As promised here are pictures of the supports installed. We couldn't do the steel sheet because on the backside of the 12" cabinets, which face the overhang, is the sink. Stacy at Amastin knew what type of granite we had and the cabinet layout and recommended installing two supports at approximately 31" apart where cabinet boxes joined together and we had extra support below. The supports are 24" long - 12" on cabinets, 12" overhang.

    We realize that the supports are farther apart than the typically recommend 16-20", max of 24", but it was by far better than not having any supports at all and we are happy with the solution. We also were very impressed with Amastin's customer service and would gladly use him again in the future.

    Here are the pictures before and after install. If anyone would like more information just let me know.

  • PRO
    Joseph Corlett, LLC
    9 years ago

    sixpacku:

    Pop a door on there, please. Let's hope the inset steel hasn't made trouble.

  • isixpacku
    Original Author
    9 years ago

    Treb - Are you concerned about the door being too large and the supports being in the way? Our GC is also the cabinet maker, and he said that he will make sure doors are modified if necessary. They are still working on finishing up the doors in the shop.

  • ajc71
    9 years ago

    Don't think that there would be much trouble making an adjustment with the doors...hinges are not installed yet, could lower those a bit and if have to trim the door

  • berryjam
    9 years ago

    Hi isixpacku,

    Just wondering if you've installed doors on those cabinets with the supports. Did the cabinet maker have to modify the door a bit so that it could open? Thanks for the info

    Jams

  • PRO
    Joseph Corlett, LLC
    9 years ago

    Jams:

    This is the very reason I suggested in the other thread that you use steel and build up the cabinet top to match. You can't inlay steel into cabinets with full overlay doors without creating serious problems.