Are corbels the best type of support?

[lovegranite]

What kind of support tools (corbels, L brackets)do you use and what do you pay for them?

Thanks,

lovegranite

[badboat]

1/4" x 2" x ?" steel bar that have countersunk holes in one end and we paint them. We dado out the wall that we attach them to. Local metal shop is where we get ours.

[Joe Little]

We order Counterbalance brackets from Chemical Concepts for raised bars and the Island brackets for top level overhangs

[topshop]

As a guy with an engineering degree - flat anything is useless unless its tempered steel and attached with a proper moment (cantellever) to secure the weight. I would trust a triangular shaped piece of wood before flat mild steel. I don't care what Chemical concepts says about their brackets - there is not enough engagement with 2x4 for the overhang they demonstrated at Expo on a raised breakfast bar application. If the overhang is 10" flat to the countertop height with 24"depth - o.k. but who puts a 2x4 wall behind cabinets at 34.5" height? The engagement needs to be at least the width of a 2x6.

[Joe Little]

We usually have a 18 " top, 12" overhang, 5" support and 1" overhang to the inside. Been using CB Brackets for 1 1/2 years, not a call back yet Maybe I'm just lucky . We actually set them to be a little higher on the outside end, so there is a little tension on the tip.

Plus, we don't have to get a 2x4 and brace up the tops because the corbels are not in place yet , and we make about 25 bucks per bracket. Best thing is not having to get corbel dims, double check everything to make sure its right. We know what we are putting it, no questions. Huge time saver, plus beer money to boot

[Mark Meriaux]

Dave must be ignoring some of the engineering principles that he has learned.

There are a number of things at play. The most important would be the object's (bartop's) Center of Mass. The WEIGHT of the bartop will be borne by the wall (or legs or cabinets). The brackets or corbels are most commonly used to prevent the bartop from tipping off of the wall - not to support the overall weight. I haven't even done statics calculations in 20 years, but if need be, I can draw one up or find an illustration online to demonstrate.

The amount of overhang vs. overall width of the top. i.e. A bartop that overhangs on BOTH sides is balanced and technically wouldn't need any support to hold it in place. Brackets and/or corbels are used as a preventative measure in the event that additional weight is placed on the top unevenly.

Whatever adhesive you use to attach the bartop to the wall is another factor. It takes quite a few ft-lbs of force to cause any considerable deflection in 1/4" steel plate - it is adequate for most granite bartop installations. You SHOULD consider the tensile strength of the anchors (lag screws) to make sure they are rated sufficiently.

We use a combination of all of the methods mentioned in this thread. 1/4" steel plate for inconspicuous mounting. Wooden corbels (various sizes) that customers can stain or paint to match their cabinetry. Chemical Concepts T-bar mounts for extreme cabinet overhangs. Most common would be the wood corbels - customers like the look and they're easy to install.

[Chris Mills]

I use the counterbalances also. I have never had a call back.

[Dan R.]

Same here, Chemical Concepts and no issues.

[Kowboy]

lovegranite:




I have no engineering background, but I can tell you these corbels are inadequate to support granite, which is why I got this call.


However, ¾” aluminum square tube countersunk, leveled and screwed into the supporting wall is more than adequate to support a granite top.


The square tube cannot be readily seen and there is nothing to knock your knees against when sitting at the bar.

While I appreciate the engineering perspective, as a student in the School of Hard Knocks, I’ve studied and perfected the Drunken Brother-In-Law test for countertops. To eliminate all the scientific jargon, it simply means that if your customer’s brother-in-law comes over and gets really drunk, is he going to be able to cause your granite to fail by dancing on the top or leaning his body on the edge? If not, your installation passes.

I visited Chemical Concepts Counterbalance:
http://counterbalanceshop.com/CB%20Sale ... 20more.pdf

After having done so, I'm inclined to agree with Dave. Strip steel on the flat with no triangulation just isn't strong enough for me. Don't confuse the Island Bracket instructions and use drywall screws for the plate. Drywall screws are for hanging drywall, they are cheap as hell and have little strength in shear. I'd also be concerned with the plates sagging over time.

Joe