Slippery Rock Gazette

Mark McMunn

Above: 2cm compared to 3cm: at 1/3 the weight, 2cm is safer and easier to handle.

Above: The Pro Edge IV is still an industry favorite machine.

Since the beginning of 2018, engineered quartz stones have continued their takeover of the stone countertop landscape. Someone else will have to provide the statistics to confirm what everyone already knows, and that is engineered stone (ES) has surpassed the sales of natural stone in the American market. Other than displacing natural stone, there are still other unintended changes that the dominance of ES will foment. The decline of 3cm may be one of those unintended consequences.

Before the kitchen countertop revolution began back in the early 1990s, the vast majority of slabs sold were 2cm in thickness. If we look at the long history of slabs, the achievement of 2cm slabs had been a goal for many decades; that is, producing thinner slabs to lower costs and to make the pieces lighter for workers to handle and install. For decades prior to that slabs usually just had one good face that was planed and polished with the backside being uneven in thickness and the surface rippled.

This did not really matter because stone floors made from slabs were set in thick mortar beds that allowed the uneven backside of the pieces to be set level and flat, so why go through the expense of grinding the backside flat when any differences in adjacent pieces would be negated in the mortar bed? 

For wall veneer the same principle applied because the backside of the slab would not show, and there would be sufficient space to allow for the unevenness of the pieces when installed. Wall veneer edges were either dressed and abutted to each other or were quirk mitered at the corners. When it came to countertops, if a slab had an uneven edge the stone worker would simply dress the edge to a consistent thickness by grinding, or mitering or abutting a skirt piece to the countertop front. Those last processes just mentioned, mitering or abutting a skirt piece, are the main issues that ushered in the demand for 3cm, when the demand for kitchen countertops took off.

Everything was so much easier with stone countertops before the 1980s. Clients were happy with flat, single-thick, polished edges until someone got the bright idea of laminating the edge and shaping a 180 arc bullnose, creating a nearly 1.5-inch thick edge. To be sure, this was a nice look. Though it was a real pain to make, all of the shops quickly learned how to make them by hand since router bits were still some years away. The clients were willing to pay a premium price for the new double-thick bullnose edge. The trouble was that there were not enough skilled stone workers to keep up with the quickly rising demand, and thus the stage was set for the rise of 3cm slabs.

Because the market demand created a huge vacuum that could not be met by existing shops, the newer shops, not even knowing how to badly polish an edge, much less how to properly laminate an edge and shape it, saw a solution to their skill set deficiency in 3cm slabs. By bullnosing a 3cm slab, the lamination process could be skipped and the bullnose, although thinner than the 1.5 inch of the laminate, was still very attractive. 

Also, in the early 1990s an Italian company had developed a handheld router along with shaped diamond bits that would allow for unskilled labor to shape and polish bullnose edges with just a few hours of training. The battle between 3cm and 4cm edges would rage until Park Industries introduced the Pro Edge sometime in 1992. 

The Pro Edge would prove to be the ultimate machine for making the difficult and time-consuming bullnose edge. A very skilled shop worker could put out about one foot of polished 4cm bullnose per hour but would be very tired at the end of the day. 

The Pro Edge in contrast could put out about 10 linear feet per hour of finished 4cm bullnose. Shops were not indifferent to the fact that if the Pro Edge could put out 10 linear feet per hour at 4cm, then it could put out even more at 3cm thickness per hour, right? The profit motive was too overwhelming, and many shops began to tell outright negative lies about laminated edges while touting the virtues of 3cm. Later, a price would be exacted for those lies and exaggerations.

The ultimate in light, thin stone: VersaLite natural stone laminate is so thin it bends.

Finally, with the advent and proliferation of CNC machines, the fix was in for 3cm to dominate. To come right to the point, 2cm slabs of natural stone don’t always get along with CNC machines. Natural slabs of 2cm, be they marble or granite, are prone to bowing that cannot always be straightened out by even the strongest suction cup system, resulting in the router bit digging into the finished face of the slab in parts of the edge, a pain to fix, and sometimes not fixable. Because of its thickness, the 3cm slab is generally free of bowing, and because of its extra weight is more securely held by the suction cup system. So, for many years now 3cm slabs have been the dominant thickness due to the factors mentioned above. Now, with the current love affair with ES and the mitered edge, the industry may begin to see that 3cm’s time may be up, and perhaps not a moment too soon.

No one can blame a business for maximizing revenue and profit, for that is its “raison d’etre,” but at that time, things began to get out of control with 3cm slabs, and the industry’s inexperience with 3cm slabs was most sadly manifested by the death of workers who were crushed by giant-sized 3cm slabs that were many times more than ¾ ton in weight. Everyone has a story about working with the huge, heavy slabs.

The tide is clearly changing for 2cm. The manufacturing kinks with ES are rapidly getting worked, out and slabs are becoming more and more consistent. Also, the 2cm ES slabs are very flat and very strong compared to natural stone and negate the problem of bowing and breakage so prevalent with 2cm natural slabs. It is now very easy to fabricate 2cm ES slabs on a router. There is still some bowing to deal with, but not any more than 3cm slabs of some granites. This, combined with the fact that the mitered edge is now the most specified edge throughout the United States, begs the question of why we are mitering 3cm slabs when we will get the same result and square footage with 2cm? A 2cm slab is 1/3 lighter than a 3cm slab of the same material, which makes it easier to handle and install.  A 2cm slab is 1/3 thinner than 3cm and means less cutting. In fact, 2cm now has all these factors going for it that reveal 3cm slabs for the overkill that they are in today’s market. That is, too heavy and too thick for the desired end product. Think of this. If a countertop calls for a 6-inch skirt to be mitered on, why, oh why would you use a 3cm slab when a 2cm will do, and in the end no one will even know whether the countertop is 2cm or 3cm?

One would think that, at least in the stone business, the desire of the end fabricator would be to have slabs that are thinner, stronger and cheaper at all times. This historical anomaly of reverting to thicker and more expensive 3cm was caused by an imbalance of market forces of supply and demand, and the lack of available technology to meet that demand that has now been resolved. From this point in history, it appears that the industry is back on the rational track of pursuing the concept of thinner, stronger, cheaper as far as slabs are concerned. Many of you reading this may disagree, but many of you will agree that a world where all countertops are made from 2cm or even thinner is a world that is lighter, cheaper and safer for all parties involved. There will always be a need for 3cm in architectural applications, but as for 3cm for countertops, the heady days of 3cm may be coming to a close.