What Is the Difference Between a Soapstone and a Clay Core?

If you’ve been researching electric radiators, you’ve probably encountered terms like “storage core,” “heat retention,” and different core materials. Two common materials are soapstone and clay (also called chamotte or grog). But what’s the difference, and why does it matter?

What Is Soapstone?

Soapstone is a natural metamorphic rock that’s been used for thousands of years in heating and cooking. It’s composed primarily of talc (60%+) along with chlorite, pyroxenes, and micas.

Soapstone is prized for its exceptional ability to absorb, hold, and radiate heat without burning or melting. This makes it ideal for heating applications.

The NEOS Soapstone Core

At Trust Electric Heating, we chose soapstone for the NEOS electric radiator because of its superior heat retention properties. But here’s what makes our soapstone core unique:

We’ve found a way to compress 16cm of soapstone into just 2cm using 200 tonnes of pressure. This compression makes the soapstone incredibly dense and non-porous, ensuring:

• Very fast warm-up time

• Longer heat retention

• Maximum efficiency

The compressed soapstone core is what allows the NEOS to continue warming your room even after the heating element switches off.

What Is a Clay Core?

Clay cores (chamotte or grog) are made from fired clay material. Many German and European electric radiators use clay cores as their storage element.

The problem with clay? It’s porous.

Why Porosity Matters

Clay cores are porous, meaning they have tiny holes and gaps throughout the material. When moisture from the air passes through these pores, it causes the clay to expand and contract.

Over time, this expansion and contraction creates small cracks in the core, similar to how a river bed forms through erosion. These cracks worsen over time, reducing the core’s ability to store and retain heat effectively.

Think of it like a sponge. A porous material absorbs moisture, changes shape, and eventually degrades. A non-porous material like compressed soapstone remains stable and durable.

Soapstone vs Clay: The Key Differences

Heat Retention:

• Soapstone: Superior heat retention. Stores heat efficiently and releases it gradually over extended periods.

• Clay: Moderate heat retention that degrades over time as cracks develop.

Durability:

• Soapstone: Non-porous, does not crack when exposed to moisture. Maintains performance for decades.

• Clay: Porous, prone to cracking from moisture exposure. Performance degrades over time.

Longevity:

• Soapstone: Lasts 25+ years without performance loss (backed by our 25-year guarantee).

• Clay: Performance deteriorates as cracks develop, typically within 5-10 years.

Density:

• Soapstone (NEOS): Compressed to extreme density (16cm reduced to 2cm), maximizing storage capacity.

• Clay: Less dense, lower storage capacity per volume.

We also encourage you to ask your heating advisor to show you the “Soapstone Test”, a demonstration of soapstone’s superior heat retention compared to other materials.

Why This Matters for Your Home

The core material directly impacts:

• How long your radiator stays warm after switching off

• How efficiently it uses electricity

• How long it lasts before needing replacement

• Your overall running costs

A soapstone core means your NEOS electric radiator continues warming your room using stored heat, reducing the time it needs to draw electricity. A clay core loses this efficiency over time as cracks develop.

The Bottom Line

Soapstone cores offer superior heat retention, durability, and longevity compared to clay cores. The NEOS electric radiator uses compressed soapstone that’s non-porous, crack-resistant, and guaranteed for 25 years.

Since 2014, thousands of customers across the UK have chosen Trust Electric Heating for radiators built with premium materials that actually last.

Experience the Soapstone Difference

Want to see and feel the difference soapstone makes? 

Call 0800 5999 109 or email [email protected] for a free consultation and demonstration.

Trust Electric Heating, premium materials, lasting performance.

Scott Conor

Chief Technical Officer

In 2012, Scott founded Trust and invented the NEOS electric radiator after finding a gap for a more innovative and cost-effective electric radiator within the industry. He’s the driving force behind Trust’s research and development, using market-leading strategies to keep customers warm.

Meet the Team | More Blogs from Scott

Tags: General Guides.