Specification guide
Thickness is rarely a strength decision. On an engineered quartz worktop it is a combined decision about the visible edge, the span between supports, the weight the cabinets carry and how much area a container can deliver. Here is how those four things trade off.
The material does not change. Every slab on this site is the same pressed engineered quartz whatever the thickness, and the polished face is identical. What changes is mass: roughly 36 kg per square metre at 15 mm, 48 kg at 20 mm and 72 kg at 30 mm. Those figures are not a theoretical density — they are the numbers that fall out of our own loading plan, where a 20' container reaches about 25.8 tonnes net at each of the three thicknesses.
That extra mass is the source of almost every downstream consequence. It decides how many square metres ship for the same freight, how much load the carcass under a worktop has to carry, whether an overhang needs a hidden support, and whether a 30 mm edge can be left square or has to be mitred. Start with mass, then work outwards.
A 15 mm slab is the right answer when the job is area-driven rather than edge-driven. Wall cladding, large floor runs, shower surrounds and long commercial counters all cover a lot of square metres without asking the edge to make a statement. On those jobs, shipping twice the area in the same container is a real cost difference, not a rounding error.
The trade-off is the edge. A 15 mm front edge reads thin on a kitchen island, so fabricators normally build it up — either a bonded strip under the front or a mitred downstand that makes the edge look like 30 or 40 mm. That is extra workshop time and a visible joint line on the return, so agree it at the drawing stage. Ask us which slab formats are available in 15 mm before you fix the layout: our 2440 × 750 mm format only runs in 15 and 20 mm.
For most kitchen and vanity worktops, 20 mm is the quiet compromise. The edge is substantial enough to polish and profile without a build-up, the weight is manageable for two fitters, and the span between cabinet supports behaves predictably. It is also the thickness most fabricators quote without needing to add a line for edge work.
If a project has no strong reason to go thinner or thicker, specify 20 mm and spend the decision time on colour instead. Our standard formats all cover 20 mm, including the 3200 × 1800 mm jumbo, which is the one that lets a long island run without a joint.
Thirty millimetres is specified for the edge, not for the surface. A solid 30 mm front, a chunky island with no laminated downstand, or a reception desk where the stone is meant to read as a block — those are legitimate reasons. The cost is that the same 20' container delivers roughly half the square metres it would at 15 mm, because the payload is fixed by weight.
Be honest about what the client is buying. If the 30 mm look is achieved with a mitred edge on a 20 mm slab, the client gets the same elevation at almost the same area yield, and the mitre is a workshop decision rather than a shipping one.
Thickness does not remove the need for support. A breakfast-bar overhang, a sink cut-out and a hob aperture all concentrate stress in ways that a flat span does not. Corner radii at cut-outs, additional battens under long overhangs and a sensible distance from the edge are fabricator decisions, but they have to appear on the drawing before the slab is cut — they cannot be added afterwards.
The heavier the slab, the more those details matter. A 30 mm island overhang carries twice the load of a 15 mm one for the same projection. If the design has a long cantilever, ask the fabricator to confirm the support plan and put it in writing alongside the cutting list.
For 3200 × 1600 mm slabs, a 20' GP leaves our plant with 140 slabs at 15 mm, 105 at 20 mm and 70 at 30 mm — seven wooden pallets in every case and about 25.8 tonnes net each time. In area that is roughly 717, 538 and 358 square metres. Quartz fills a container by weight before it fills one by volume, so the thinner the slab, the more surface you buy with the same freight.
This is why a quotation should always state the thickness. A price per square metre that looks cheap at 30 mm can be more expensive per delivered square metre once the freight is divided across fewer slabs. Ask for the loading plan with the quotation; we send it as a matter of course.
Our specifications page lists the four standard formats, the thicknesses each one runs in and the full container loading table. The colours page lets you filter the range by family and style; if you are choosing a pale, low-contrast slab such as Carrara Alba or a plain white such as Solid Bianco, remember that lighter grounds show joint lines more than darker ones — thickness and seam placement are worth deciding together.
Tell us the square metres, the thickness and the destination port and we will come back with a price, a packing plan and a lead time.
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Send the colour codes, the square metres, the thickness and the destination port. We reply with a price, a packing plan and a lead time.
