2- “How big is an inch?” The difference between zinc tops and stone.


Today we’re going to talk about a challenge facing the metal countertop industry. How do the construction basics for zinc bar tops differ from natural stone and prefab or composite surfaces? Let’s start by understanding the difference between countertops and bar tops.

Countertops vs Bar Tops

Countertops are surfaces that install over cabinetry. In most cases, the cabinet box provides enough support for the top. Sometimes when we bridge large knee openings or encounter other special circumstances, additional support is required in the form of a countertop subtop.

Bar tops are surfaces that install over a die wall. A bar die wall is a thin wall or pony wall that holds up the bar. Sometimes, brackets can support small tops with minimal overhangs sufficiently. For larger tops with normal overhangs between 9″-12″, a subtop is required.

A subtop is usually a 3/4″ piece of plywood that bridges seams in the zinc tops and attaches directly from the top side to the die wall below. 3/4″ is the golden standard for plywood. Thinner than this, and the plywood subtop doesn’t serve its primary function. In special cases, we can use 1/4″ plate steel, but it will incur a much greater cost.

Next, let’s look at the difference between a stone installation and a zinc installation as a countertop.

A natural stone installation as a countertop uses corner blocks and rails to secure the 1.25″ thick slab directly on the base cabinets. Silicone bonds the box to the stone slab.

Sometimes manufacturers use engineered buildups where the material is as thin as 1/2″. This material is laid over plywood, which is concealed internally. This is done for economy of material and generally results in a poorer performing product.

You can also install zinc tops directly on cabinetry, but you must always mechanically fasten them instead of gluing. This is done through the cabinet corner blocks. Most manufacturers fabricate zinc tops 1.5″ thick. This is because the core is two pieces of 3/4″ plywood.

For residential installs, the 1/4″ difference between stone and zinc is relatively inconsequential for practical and ADA purposes.

Zinc Die Wall Bar Construction

For bar tops, these construction details matter much more. Ultimately, it affects the height of your die wall specification.

As most manufacturers make zinc bar tops 1.5″ thick with a 3/4″ subtop, the final assembly comes to 2.25″. This varies greatly from stone that can be as thin as 1.25″ if supported with brackets.

What does this mean for your project?

Well, you have to understand the construction details for the specific product, and adjust accordingly. Often, it’s not as simple as decreasing the thickness of the material for the top or eliminating the subtop. Specify a shorter wall construction in case you plan to use a zinc top but haven’t chosen a supplier yet. You can build up this detail at a later time more easily than you can reduce it on-site.

Not considering this additional inch in design can have a significant impact on your bar height. It can also affect ADA compliance, user experience, and other bar finishes.

The zinc countertop industry faces a challenge with a different standard than most stone tops. Design considerations must be made with some products to accommodate this difference.

How is 3 Spark Different?

At 3 Spark, we have already identified this issue and adjusted our product to alleviate your pain. Because we use a solid core substrate, we can manufacture zinc bar tops, tables, and countertops in standard 1.25″ thickness. This is the same as the natural stone industry, and it helps alleviate a lot of headache and planning by you, the designer.

Contact us today so that we can help you get started specifying the details of your next project!

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