What is LECA® LWA?

What is Leca® Lightweight Aggregate (LWA)?

Leca ® Lightweight Aggregate (LWA) is a natural, unique and sustainable lightweight clay aggregate. LECA® LWA has remarkable properties which ensure its versatility for use in a vast number of structural and geotechnical applications. It is the only "all in one" aggregate solution for Architects and Civil Engineers to overcome problematic areas in construction and design. Thanks to its unique properties, expanded clay has a broad range of applications from residential housing, commercial building, structural and geotechnical build and horticultural and landscape projects and is emerging as an environmentally sustainable and more effective alternative to traditional heavyweight and cumbersome aggregate.

When responsible for large or small-scale construction projects, to make the building process cost-efficient and run more smoothly, building materials need to be easy to handle, easy to transport and flexible to work with. LECA® LWA can achieve all of this.

Close Up of Leca®?
Close Up of LECA® LWA

Whilst LECA® LWA is a simple product, our solutions are innovative. Alone, it is one single expanded clay pellet, but when combining the pellets into an aggregate, the civil engineering possibilities become endless - whether it is lightening road and railway embankments, insulating and filling of swimming pool surrounds, reducing pressure within quay extensions, lightweight fill in foundations and behind retaining walls, general load compensation, within structural elements, insulating and lightening pipelines, drainage and insulating sports pitches and courts, lightening the load over tunnels and bridge development and much more. The simplicity of this product makes it extremely versatile and flexible in the construction process.

•    Stability – reduces the risk of embankment landslide and deformation
•    Reduced settlements - less damage to road structures, rail beds, pipelines and other structures
•    Reduced earth pressure - in structural backfill against foundations, retaining walls and bridge abutments
•    Drainage - on sports grounds, fields, slopes and roads
•    Insulation - protection for roads surface, structure, pipelines and service mains
•    Frost stability - in road and rail beds
•    Limited compaction – Exerted energy during compaction is minimal with a reduction in volume of approximately 10 - 12%.
•    Low density and ease of handling, coupled with consistent high quality, make Leca® LWA a highly competitive alternative to other lightweight materials.

Leca during pneumatic installation
LECA® LWA during pneumatic installation


During the LECA ®  LWA manufacturing process, natural clay is kiln-fired at high temperature to create an incombustible ceramic material. The individual clay particles begin to fuse at 950°c, and the clay material begins to melt at temperatures exceeding 1150°c to form the ceramic shell of the honeycomb pellet. 

LECA ® LWA can be used in a variety of structural and geotechnical type projects and its significant properties such as being light in weight, extremely strong and ease to handle have proven that LECA ® LWA is for many civil engineers the aggregate of choice. LECA® LWA is a simple and powerfully effective alternative to conventional aggregates with the advantage of being able to be pneumatically blown into difficult to access locations, allowing construction time to be significantly reduced in comparison to other solutions containing heavy aggregate materials.

Leca during installation
LECA® LWA during installation

The dry bulk density of LECA ® LWA intended for earth works application is approximately 15 – 20 % of that of traditional granular aggregates and soils.

The mechanical properties of LECA ® LWA vary according to the size and expansion rate of its constituent aggregate particles. In general, due to the percentage of ceramic shell, smaller particles are more durable but also tend to be heavier in weight.

All LECA® LWA products are produced with a Declaration of Performance (DoP). Detailed information on product performance certificates specified by corresponding standards can be found in the LECA® LWA Technical Documents area. For more information about Leca® LWA, please refer to our FAQ or contact us and speak to us directly.

* Note: Formerly known in the UK as Optiroc and Maxit.