Structure

LECA (Expanded Clay).

LECA is a moderate CO₂ material combining low weight with good insulation performance. Well suited to foundations and basements where moisture resistance is important.

Key Figures

Carbon Footprint (GWP): 0.3 kg CO₂-eq/kg
Density: 400–700 kg/m³
Expected Lifespan: 100+ år

What is leca (expanded clay)?

LECA is lightweight expanded clay aggregate. It is light, has good insulating properties, and is resistant to moisture and rodents. Often used for foundations, basement walls, and as fill material. It has a moderate carbon footprint compared to ordinary concrete.

Carbon Footprint Compared

LECA ← this material 0.3 kg CO₂/kg

Concrete 0.13 kg CO₂/kg

Brick 0.23 kg CO₂/kg

CLT −0.55 kg CO₂/kg

Negative carbon footprint (green) indicates carbon storage. Data based on EPD averages from ECO Platform and estimates per EN 15804.

Typical Applications

check_circle Foundations
check_circle Basement walls
check_circle Fill layers under floors
check_circle Roof terrace substrate
check_circle Lightweight concrete elements

In Renovation

LECA is used in renovation for filling under new floors, for damp-proofing basements, and for lightweight extension masonry. The advantage is that it can be laid without heavy machinery and tolerates moisture.

Questions about leca (expanded clay)

What is the advantage of LECA over regular concrete?

LECA blocks are significantly lighter (approx. 30% of concrete weight) and have better insulating capacity. They are easier to work with, require no heavy machinery, and are well-suited for self-build.

Is LECA moisture resistant?

LECA is highly resistant to moisture — it is actually one of the materials recommended for basements and damp environments. It does not rot and is resistant to mould.

Can LECA be used as insulation?

Yes, expanded clay granules are used as insulating fill layers under ground-floor slabs and on roof terraces. They provide good capillary break and a lightweight structure.

Is LECA better than concrete for climate impact?

LECA blocks typically have slightly higher GWP per kg than concrete, but much less material is used per m² of wall (they are hollow). Total climate impact can be lower.

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