Refractory clays and grogs

Clay and grog: the basis of traditional refractory mixes

Refractory clays and grogs are the fundamental materials of refractory masonry. Used for centuries in the construction of ovens and heating appliances, they offer a unique combination of resistance to high temperatures, thermal inertia and structural stability.

Clay acts as a natural binder, while grog — clay that has been fired and then crushed — serves as a stabilising refractory filler. This combination limits shrinkage on drying and improves the mechanical strength of structures exposed to large temperature variations.

An ideal material for masonry heaters and wood-fired ovens

Clay and grog mixes are particularly suited to:

• building handcrafted masonry heaters

• bread ovens and pizza ovens

• masonry for fireboxes and combustion chambers

• traditional refractory renders

• repairs to firebrick structures

Thanks to their ability to absorb and release heat, these materials contribute directly to the thermal performance of wood-burning heating appliances.

Several grain sizes to suit every use

Grog is available in different grain sizes so that the mix can be adapted to the application:

• Fine grog: refractory grouts and renders

• Medium grog: mortars for firebrick masonry

• Coarse grog: casting refractory concretes and heat-storage masses

This variety makes it possible to compose formulations perfectly suited to the mechanical and thermal constraints of each project.

Natural, proven materials

Clay and grog offer many advantages for refractory construction:

• excellent resistance to high temperatures

• low thermal expansion

• good inertia and heat storage

• perfect compatibility with firebrick

• natural, durable materials

These properties make them a preferred choice for craftsmen, self-builders and wood heating professionals.