Here are the technical drawings of my island with the giant overhang. I greatly appreciate any advice about making this kid proof/as safe as possible. Thanks! - Amy

Any counter material is safe, with the correctly designed steel tubing subframe that you need. Big dedign engineering needed by someone with a clue.

But really, that is not a good design, and the cooking zone in the island needs more space than that, and so do the aisles. That is not a functional design. Not at all.

Start over with a better kitchen designer. One who actually understands NKBA design standards and clearances.

Amy:

The key here is looking at your countertop as veneer to cover the structure that does the work. If you and your kids can't stand on your substrate with very minimal deflection, preferably none at all, it is inadequate.

Be sure you tell your fabricator that you understand the cost of a proper substrate. No plywood please; it's too flexible as is steel-on-the-flat. Square tube steel or aluminum, or a 4" wood apron possibly with a leg or two.

Thank you so much for this very helpful feedback! It sounds like there's agreement that a quartzite slab can be safe with a properly designed “steel tubing subframe”. Can anyone please advise me on how to find someone who knows how to construct this properly, in New York City? Is there a certain degree or certification that they would have, or would they be connected with a certain association? Also, with the added weight of a steel subframe, is there any concern with tipping? Finally, with a steel tubing subframe, would it be safe to install a 2 cm Crystallo quartzite, or would it be important to install something stronger like a 3 cm Taj Mahal quartzite? Thank you again! This is very helpful!

Regarding the question of what is the safest option for my giant countertop overhang, there is a half inch variation in height of my floor. I assume the installer will put shims under the kitchen island where needed, but does this weaken the structure to the point where I should install a counter that will be lighter than quartzite supported by a steel tubing subframe? Is 3 cm quartz installed with brackets my safest option because it would, I think, be lighter?

Have you had floor joists checked, to make sure it can handle the weight of a heavy steel frame, and a very heavy stone countertop. Thats a lot of weight for your floor to handle, unless it has been beefed up a bit underneath it. I agree, redesign the kitchen, to get your stove over on to a countertop, and not on the island. You obviously want the kids to use the island. Its not safe to have a stove top there.

Regarding the question about floor joists, I live in an apartment building with concrete subfloors.

Another NYC apartment dweller here with concrete subfloors. Your weight will not be an issue with the floors.

Be sure to consider your elevator measurements and the size of your largest counter. The previous owners of our apartment fabricated a quartzite counter so large it wouldn't fit in the elevator and that the crew had to carry it up 12 stories. Freaking insane, frankly inhumane.

I realize there are a lot of constraints in a NYC apartment. But I do concur with others, if there is some way to get your burners on the long wall and out of the island, it will be so much safer, not only with kids, but adults passing by too.

Does your gas line have to run to this island area? Did there used to be a wall here as the other side of a galley kitchen that has been opened up into open concept?

Many other people look at a Manhattan kitchen layout and say "Your designer is horrible. Go elsewhere." But the reality is there are so many insane constraints to deal with. Perhaps this is actually the best layout. Don't know. But you will get insanely good advice here if you post your whole plan and some info about your limitations.

Good luck!

"Have you had floor joists checked, to make sure it can handle the weight of a heavy steel frame, and a very heavy stone countertop. Thats a lot of weight for your floor to handle, unless it has been beefed up a bit underneath it."

There is no need to check framing on any residence that has been build to modern framing standards. None.

“There is no need to check framing on any residence that has been build to modern framing standards. None.“

The key word is modern. I lived in an old home that originally had no kitchen. It was later added on a pile of coal ash. There was framing, but the noists could not hold the weight of the kitchen (and the room above.) It was a nightmare. Never a bad ideal to explore the foundation under a kitchen on which you are building if it is an old house or old building.

Thank you for the helpful feedback. I realize the placement of the range isn't ideal but we're not allowed to touch the gas line and I would never put anything hot on the 7 inches of counter next to the stove. I would like to respectfully steer the conversation back to making the overhang as safe as possible, considering that we want to install a 2 cm Crystallo countertop. I'm so grateful for the insight that we should be treating the crystallo quartzite as a veneer, supported by a properly designed steel tubing subframe with no deflection. I was surprised to learn that quarter inch thick metal plates won't work, and I've never heard of a steel tubing subframe. When I've reached out to fabricators, and to my general contractor, they simply suggest using hidden brackets, and a couple have suggested plywood support beneath. I would greatly appreciate it if anyone has advice about how to find an expert in New York City with experience and expertise in building the steel tubing subframe that the 2 cm crystallo overhang requires?

"they simply suggest using hidden brackets, and a couple have suggested plywood support beneath..."

I'd discuss the idea of steel tube frame with your current fabricator and contractor. Tell them you have heard it mentioned as a good idea for your material and situation. See what they say. It could range from "no way, it's overkill" to "I've never heard of that" to "yeah, I've used that a couple of times. If it makes you feel better, we can do that and just charge you more." Give your own people a chance to respond and hash it out with you before you start hunting for new fabricators.

Lastly, I know you can't entirely move the cooktop because of the gas line - same situation in my building. But, you could center it on this island and vastly reduce your chances of a trip to the burn unit. Why did your designer not suggest this?

How about changing to an induction range?

Thank you so much for this very helpful feedback! I've narrowed the options down to two, and am wondering which option provides more support for the giant L-shaped overhang, with my two centimeter cristallo quartzite: 

1. A 3/8 inch steel slab across the entire island, supporting the 2 cm cristallo quartzite 

OR

2. A 1.25 inch by 1.25 inch tubular steel frame embedded in the cabinets, with a subtop of either 2 cm quartz or a ⅞ inch “safeboard” overhang support panel (made of aluminum honeycomb bonded between two “ridgid skins”) ++https://safeboardpro.com/safeboard-osp/++

I would greatly appreciate any insight into which option offers more support and makes the most sense. I am wondering which option would be safer in the event that somebody one day sat on that giant corner overhang. I'm also wondering if either option would create too much weight on the cabinets? The cabinets are Dura Supreme’s frameless Bria cabinets and are made with three quarter inch plywood but the panels are furniture board.

#2 is much much more ridged. WITH a couple of posts. NO cantilever that distance period. Sheet steel still flexes.

If your cabinets are frameless and your top 2cm with a 2cm built-up edge, you don't have room to cover 1 1/4" square tube steel completely and it can't be let into the cabinets without dropping the doors/drawer fronts. You'd have to use 18 gauge 3/4" which will sit on top of the cabinets and be covered by the edges of the top.

3/8" steel-on-the-flat with or without plywood is too floppy.

Thank you so much Joseph Corlett, Minardi, and everyone else who has offered their insight! To clarify, Joseph, when you say, “You'd have to use 18 gauge 3/4" which will sit on top of the cabinets and be covered by the edges of the top.” does this mean I can't embed them within the cabinets, I have to sit the steel tubing frame on top of the cabinets? If so, do I need a flat surface on top of the tubing frame so that the 2cm cristallo is completely supported by a flat surface rather than just a frame? If so, what do you suggest using as a flat solid surface on top of the tubing frame, for the 2 cm cristallo to rest on? 

Also, would this 18 gauge, 3/4 inch tubing frame solution make it unlikely for the corner overhang to break if someone, someday sat on it? 

Finally, Minardi, my husband and I definitely don't want to install a leg for support. Assuming that there will be no leg installed, should the 17-inch portion of the L-shaped overhang be reduced for safety and, if so, by how many inches should I reduce this side of the overhang? 

Again, many thanks for your insight!

"... does this mean I can't embed them within the cabinets, I have to sit the steel tubing frame on top of the cabinets?"

If your cabinets are frameless you cannot imbed the frame.

"Do I need a flat surface on top of the tubing frame so that the 2cm cristallo is completely supported by a flat surface rather than just a frame?"

No, the frame is plenty of support.

"Also, would this 18 gauge, 3/4 inch tubing frame solution make it unlikely for the corner overhang to break if someone, someday sat on it?"

Highly unlikely.

Joseph Corlett, thank you so much for identifying a way to install the fragile Cristallo over my large L-shaped overhang safely. The L-shaped overhang is 16 and 1/2 in deep on one side, 12 in deep on the other, and the overhanging corner / hypotenuse is around 21 inches.

Because I can't embed a steel tube frame into my frameless cabinets, and the frame would have to sit on top, I find that the frame would add a bit too much height, and the fabricator’s quote was a bit over budget. 

Therefore, my husband and I are now thinking of using 3 cm quartz because it is stronger. Is there a way to support this corner overhang safely without adding additional height? I'm okay with building out the cabinetry and reducing the overhang, if you think that's advisable. I was wondering if there is a bracket or steel tube solution for supporting the corner of my overhang very well without raising the height of the slab? (There is one and 1/8 inches between the top of the drawer and the top of the cabinetry.) 

Again my goal is that if somebody sat on the corner, no one would get hurt, and ideally the slab wouldn't break. Your advice is greatly appreciated!

Joseph Corlett, thank you so much for identifying a way to install the fragile Cristallo over my large L-shaped overhang safely. The L-shaped overhang is 16 and 1/2 in deep on one side, 12 in deep on the other, and the overhanging corner / hypotenuse is around 21 inches.

Because I can't embed a steel tube frame into my frameless cabinets, and the frame would have to sit on top, I find that the frame would add a bit too much height, and the fabricator’s quote was a bit over budget. 

Therefore, my husband and I are now thinking of using 3 cm quartz because it is stronger. Is there a way to support this corner overhang safely without adding additional height? I'm okay with building out the cabinetry and reducing the overhang, if you think that's advisable. I was wondering if there is a bracket or steel tube solution for supporting the corner of my overhang very well without raising the height of the slab? (There is one and 1/8 inches between the top of the drawer and the top of the cabinetry.) 

Again my goal is that if somebody sat on the corner, no one would get hurt, and ideally the slab wouldn't break. Your advice is greatly appreciated!

Joseph Corlett, thank you so much for identifying a way to install the fragile Cristallo over my large L-shaped overhang safely. The L-shaped overhang is 16 and 1/2 in deep on one side, 12 in deep on the other, and the overhanging corner / hypotenuse is around 21 inches.

Because I can't embed a steel tube frame into my frameless cabinets, and the frame would have to sit on top, I find that the frame would add a bit too much height, and the fabricator’s quote was a bit over budget. 

Therefore, my husband and I are now thinking of using 3 cm quartz because it is stronger. Is there a way to support this corner overhang safely without adding additional height? I'm okay with building out the cabinetry and reducing the overhang, if you think that's advisable. I was wondering if there is a bracket or steel tube solution for supporting the corner of my overhang very well without raising the height of the slab? (There is one and 1/8 inches between the top of the drawer and the top of the cabinetry.) 

Again my goal is that if somebody sat on the corner, no one would get hurt, and ideally the slab wouldn't break. Your advice is greatly appreciated!

I apologize for the two duplicate posts. It seemed that my post wasn't sending but it was actually delayed.

If you use 3cm engineered stone, I wouldn't worry about any additional support.

Joseph Corlett,

Thank you for your advice that I don't need additional support with 3 cm stone. However, I'm confused because I understand that the guidelines for 3 cm quartz are that overhangs can be unsupported up to 14 in. But my overhang is 21 inches where the 16-in overhang and the 12-in overhang meet. Doesn't this require brackets? And is there any special bracket for corner overhangs?

Also, does my design violate the 1/3 rule?

Thank you so much for your help and expertise! It is greatly appreciated!!