LECA concrete or normal-weight concrete? When lightweight pays off

Expanded clay (LECA) concrete is concrete in which the natural aggregate is replaced with expanded clay — granules of fired clay. This single substitution changes three parameters at once: weight, thermal insulation and water absorption. Below is a comparison with normal-weight concrete where the difference matters in practice.

Weight — transport and the crane

A LECA concrete element is markedly lighter than its normal-weight concrete counterpart. More metres of wall fit on a single vehicle, and a smaller crane is enough on site. On a single-family house this can decide whether the installation can be carried out from a single crane position.

Insulation — wall thickness

Expanded clay traps air within its structure, so a LECA concrete wall conducts heat less readily than a reinforced concrete one. Our wall build-ups achieve U-values in the range 0.117–0.185 W/(m²·K) depending on the layer arrangement — comfortably below the Polish WT 2021 limit. The details are set out on our LECA concrete page.

Strength — where the limits lie

We use structural LECA concrete in classes from LC12/13 to LC20/22. That is sufficient for the load-bearing walls of residential buildings, including multi-family ones. Where the calculations demand more — floor slabs, beams, columns, balconies — we use normal-weight concrete up to C35/45. In a single building the two materials work side by side, and that is the typical arrangement, not the exception.

The environment — EPDs

The carbon footprint of our products is documented in the verified environmental product declarations ITB-EPD 561 and 562 — you will find the documents and a discussion on our sustainability page.

If you are wondering which material suits your project, send your documentation through the quote form — material selection is part of the quote, not an extra service.

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Frequently asked questions

Is expanded clay concrete suitable for load-bearing walls?

Yes. The selection of material and strength class is always determined by the structural design.

Does expanded clay concrete replace thermal insulation?

Not always. The parameters of the entire partition depend on its layer arrangement, so the solution is selected to suit the project requirements.

Gdzie lepiej zastosować beton zwykły?

Plain concrete is used where calculations require higher load-bearing capacity, e.g. in beams, columns, ceilings or balconies.