Lightweight expanded clay aggregate is made by heating clay, shale or slate in a rotary kiln. The kiln temperature may reach up to 2100 degrees Fahrenheit. The intense heat causes the material to expand and become lightweight aggregate.
LECA is lightweight, strong and durable. It remains stable during extreme high or low temperatures, and is not affected by high pressure. Lightweight expanded clay aggregate maintains a neutral pH.
LECA may be mixed with potting soil or used alone in plant baskets and pots. It is extremely porous, which balances the exchange of water and oxygen to create a good environment for plant roots.
Lightweight concrete can be made from LECA, which is beneficial for structural designs requiring weight reduction. LECA works well as insulation, providing soundproofing and fire resistance. It is also suitable for use as back filling behind retaining walls.