How Thin is too Thin with Indian Sandstone Paving Slab options?

How Thin is Too Thin? A Guide to Indian Sandstone Paving Slab Thickness

When planning a new patio with Indian Sandstone, one question comes up time and time again:
“How thin is too thin when it comes to paving slabs?”

If you're still weighing up Porcelain Paving vs. Indian Sandstone,

For budget-conscious homeowners, opting for thinner slabs might seem like a smart way to save a few pounds. However, while thinner paving slabs may be cheaper upfront, they can actually cost more in the long run—both in performance and durability.

Why Thickness Matters

The widely accepted industry standard for Indian Sandstone is the 22mm calibrated paving slab. This thickness strikes the perfect balance between strength, weather resistance, and cost-effectiveness. These slabs are machine-cut to a consistent depth, which makes them easy to install and reliable over time.

In contrast, thinner slabs—especially those below 20mm—are more prone to damage, particularly due to the freeze-thaw cycle experienced in UK winters.

Understanding the Freeze-Thaw Cycle

Even though paving slabs may appear solid and unchanging, they’re constantly interacting with the environment.

During colder months, any moisture trapped in the natural pores of the stone can freeze and expand—by up to 10%. This expansion puts pressure on the slab from within. When temperatures rise again, the moisture thaws, releasing the pressure. But over time, this repeated cycle of freezing and thawing weakens the stone.

Thinner slabs have less structural integrity, making them more vulnerable to cracking and failure under this kind of stress. Thicker slabs—like the 22mm calibrated option—can withstand these natural elements more effectively, offering better longevity and fewer repairs or replacements.

So... How Thin is Too Thin?

While there’s no formal industry regulation on slab thickness, experience tells us that anything under 20mm carries a significantly higher risk of failure. Here’s a general breakdown:

  • 15–18mm: Risky for long-term outdoor use. Prone to cracking under stress.

  • 20mm: A compromise between cost and performance, but less durable over time.

  • 22mm Calibrated: The gold standard. Durable, weather-resistant, easy to install, and cost-effective.

  • 25–35mm (Old Standard): Exceptionally strong, but heavier and more expensive with less coverage per pack.

Modern consumers want both performance and value. That’s why 22mm calibrated slabs are now the most popular choice—they offer enough thickness to ensure durability while still being efficient to pack, ship, and install.

Shop with Confidence at Discount Porcelain Superstore

We pride ourselves on offering only the highest quality Indian Sandstone paving—including the most trusted 22mm calibrated options in a variety of popular colours:

  • Kandla Grey

  • Raj Green

  • Rippon Buff

  • Autumn Brown

  • Fossil Mint

Whether you're tackling a DIY patio or working with a landscaper, our paving slabs are built to last and priced to impress.