Granite slab thickness is one of the most important specifications in any order — and one of the most frequently misunderstood. The right thickness for your project depends on the application, the support structure, the span and the end use. This guide explains what each thickness is used for and how thickness affects shipping cost and pricing.
Standard Granite Thicknesses
| Thickness | Weight per m² | Primary Applications |
|---|---|---|
| 1.8cm | ~45 kg/m² | Wall cladding, shower surrounds, tile overlays, backsplashes |
| 2cm | ~50 kg/m² | Floor tiles, wall panels, countertop overlays on substrate |
| 3cm | ~75 kg/m² | Kitchen countertops, vanity tops, island tops, stair treads |
| 4–5cm | ~100–125 kg/m² | Structural slabs, outdoor steps, heavy-duty flooring |
| 6cm+ | 150+ kg/m² | Kerb stones, memorial bases, heavy structural applications |
1.8cm — The Thinnest Standard Slab
1.8cm granite is the thinnest standard slab thickness and is produced primarily by multiwire gang saw cutting. It is used where weight reduction matters — wall cladding panels, shower surrounds, and as an overlay bonded to an existing substrate.
Important: 1.8cm granite cannot span unsupported gaps. It must be installed over a continuous substrate (plywood or concrete). Using 1.8cm for an unsupported kitchen countertop will result in cracking.
2cm — The Versatile Mid-Weight
2cm is the most versatile thickness and widely used for floor tiles, wall panels and some countertop applications where a substrate is provided. It is significantly lighter than 3cm, which reduces shipping costs and makes installation easier.
3cm — The Kitchen Countertop Standard
3cm is the standard thickness for kitchen countertops in most Western markets. At 3cm, granite has sufficient structural integrity to span standard cabinet widths (up to 65cm unsupported) without risk of cracking. Overhang recommendations vary by span — consult your fabricator.
How Thickness Affects Shipping Cost
Thickness directly affects the weight of each container, and weight is a key driver of both shipping cost and container capacity:
- A 40ft container of 2cm slabs can hold approximately 25–30% more square metres than the same container loaded with 3cm slabs
- Thicker slabs require more robust wooden crates, adding packing material cost
- Heavier consignments may attract higher freight rates on some routes