The European expanded clay industry has embraced the principles of sustainable development. Expanded clay is a well-proven, high quality, efficient and competitive construction material that can be used anywhere. It is sustainable and packed with properties that improve the economic, social and environmental performance of a building or infrastructure over its whole lifetime. Expanded clay is produced with the maximum care for employees, environment, climate, neighbours and local communities. The industry is committed to continuously reduce the impact from the production and to develop the properties and applications of expanded clay to improve the sustainability contribution.

Learn more about the sustainability of our industry by downloading the brochure below.




Expanded clay is a durable, fully circular natural material. It is sourced in full respect of the environment, is an excellent thermal and acoustic insulator, is long lasting and endlessly reusable and recyclable. The product’s inherent value for the circular economy encompasses:

  • Sustainable sourcing;
  • Lightness;
  • Durability;
  • Recyclability/reuse.

Expanded Clay lightweight aggregates can be excavated from the ground where they were once placed and reused in new geotechnical applications.

An example of this can be found outside Gothenburg in Sweden. In connection with the construction of a new residential area in 2008, a new road was needed. For this purpose, our member company extracted expanded clay from a nearby location and then delivered to the new road construction.

In Kungälv, near Gothenburg, 500m3 of expanded clay were also extracted and reused when building the new road.

Expanded clay was removed during roof renovations of a commercial building in Helsinki, and then used, after further processing, as roof soil for green roofs.

“In roof renovations, the old roof is dismantled and a layer of expanded clay, on average 400 mm thick and acting as heat insulation, is removed and delivered as a raw material for use in roof soil. A vapour barrier is installed onto hollow-core slabs, as well as expanded clay and 250 mm mineral wool. Expanded clay ensures adequate ventilation of the roof and it is convenient to carry out inclinations leading to roof drains,” says Lasse Ruuskanen from Eristysmestarit Oy, supervisor for the renovation of a commercial building located in Herttoniemi, Helsinki. expanded clay is removed from the roof and transported away by Anpe Oy.

Of recycled expanded clay, about 80 percent is used for geotechnical uses and 20 percent for other uses. For example, the processing value of expanded clay and soil in the manufacturing of roof soil for special use will rise with no generation of waste,” says Hannu Pesola, ANPE Oy’s managing director.

Pesola reminds us that expanded clay’s combined good properties, namely light weight, compressive strength and good thermal insulation properties are retained, even when the product is re-used.

“By taking advantage of expanded clay removed from roofs in geotechnical or other applications, one can reduce the need for new light aggregates in such applications, whereupon the capacity of a lightweight aggregate plant will improve and materials and the environment will be saved”.

Expanded clay was removed from a roof and delivered to Ralf Ajalin Oy’s Pihamaa service and soil station in Vantaa.

The aggregate was crushed and used as an important part in the manufacture of roof soil. Compared to normal soil, roof soil as a product has been processed for longer and is a more valuable specialty product,” says Olli Mannerjoki, from Ralf Ajalin Oy, responsible for Pihamaa-service products.

Expanded clay allows the soil to be much lighter, so that roof structures are not placed under excess loads. The main tasks of expanded clay aggregate in roof soil are to make the soil light, as well as to improve the movement of water in the growth base, which facilitates access to water for plants”.

During concrete block production inevitably sub-standard products are produced resulting from raw material, machinery or human inconsistencies. Typically in the large scale production of concrete building blocks approximately 0.5% of concrete produced becomes unsuitable for sale and is removed from the production line for reprocessing.

Sub-standard products are accumulated on site over a period of months until significant quantities are available at which stage crushing and sieving equipment is used to crush down the product to a suitable size and grade of raw material.

It is not possible to reprocess the sub-standard products back to the properties and grades which were used in the original concrete mix as the material produced from reprocessing will ultimately comprise expanded clay aggregate, sands and cements. Reprocessing produces a grade of material which comprises a homogeneous mix of the original recipe. From this process a new grade and specification of raw material is produced; to utilise this material a new concrete mix is designed to include the physical characteristics of the reprocessed material.


Sustainable sourcing
Expanded clay is produced from naturally and abundantly available clay, extracted from clay pits located close to the plants. We are not extracting nor using rare materials, hence we are not contributing to the depletion of the earth’s precious resources.

By considering biodiversity issues at the planning stage as well as during and after extraction, our industry ensures protection of habitats. The clay pits are restored and rehabilitated to preserve biodiversity and create new natural habitats. No abandoned industrial zones are created by the manufacturing of expanded clay.

For every cubic metre of natural and abundant clay, up to five cubic metres of expanded clay is produced. Using expanded clay saves energy and reduces CO2 emissions in the construction and transport sectors. Its low weight means fewer trucks and fewer journeys, thus reducing the carbon impact of transportation.

Expanded clay blocks and panels are primarily made of expanded clay, sand and cement. Due to the absence of organic material all these constructions are in all their constituent parts durable, predominantly blocks are frost resistant and have a very favourable water resistance and low water absorption. They are very resistant to general wear and tear, have good impact resistance and have a very long life cycle.

Expanded clay is 100% recyclable or reusable. Demolition waste containing expanded clay is disposable and not hazardous, and no use of new materials, new resources or new energy is required. Almost all of recycled expanded clay is used in civil engineering and geotechnical applications.

To facilitate the valorisation of expanded clay and encourage the reutilisation of waste in suitable applications, EXCA is presenting a range of reuse/recycling activities taking place in the expanded clay industry. The ultimate aim is to promote the implementation of best practices for a controlled deconstruction process of such expanded clay-based systems, which might ease recovery