Expanded clay aggregate, is a lightweight ceramic shell with honeycomb core produced by firing natural clay to temperatures of Template:Nowrap in a rotating kiln. The pellets are rounded in shape and fall from the kiln in a grade of approximately Template:Nowrap with an average dry bulk density of approximately 350 kg/m³. The material is sieved into a number of different grades to suit the application.
With the advantage of light weight, high permeability, high durability and excellent sound and thermal insulating properties, expanded clay is a good 'all round' aggregate for use in an a variety of applications. It is also an environmentally friendly product composed mostly of naturally occurring clay, is not susceptible to chemical attack, rot or frost and has a long life span. The lightweight nature of the expanded clay pellet make it an ideal solution when constructing over weak soil deposits or reducing the load behind old and susceptible structure. The air pockets within the pellet provide excellent thermal resistance when used as underfloor insulation within solid floor construction. The expanded clay pellets are also used extensively for the manufacture of Lightweight blocks and frequently used in water filtration systems due to their high surface area.