Cork is a natural material with exceptional insulating properties, widely used in construction for its thermal and acoustic performance. Derived from the bark of the cork oak, it combines ecology, durability and energy efficiency. Suitable for walls, floors and roofs, insulation with expanded cork stands out for its low thermal conductivity and its ability to reduce noise in residential or commercial spaces.
Advantages of cork for thermal insulation
Cork is recognized by construction professionals as one of the best natural thermal insulators thanks to its unique properties.
Thermal properties of cork
Composed of millions of air-filled cells, cork benefits from extremely low thermal conductivity, which limits heat exchange between the inside and outside of a building. This cellular structure gives it exceptional insulation capacity, maintaining a stable temperature, and consequently reducing heating and air conditioning needs. In addition, cork is a lightweight material, which makes it easy to handle and install, while offering significant resistance to humidity.
Ecology and durability
Cork also stands out for its ecological qualities. Derived from the bark of the cork oak, it is a 100% natural, renewable and recyclable material. Moreover, the cork harvesting method, which does not involve felling the tree, helps preserve forests and combat deforestation. In addition, cork oak cultivation contributes to biodiversity and the maintenance of ecosystems, in France and elsewhere. Another interesting point: cork production generates little waste and carbon emissions.
Thermal performance of cork: conductivity and resistance
Cork is particularly valued for its exceptionally low thermal conductivity, which is one of the lowest among natural insulation materials, most often ranging between 0.037 and 0.040 W/m K. As a result, cork acts as a true barrier against heat transfers, from inside to outside, and vice versa.
Cork also has high thermal resistance, reaching approximately 1.25 m²·K/W with a 50 mm thick panel, 2.5 m²·K/W for 100 mm thick, and 5 m²·K/W for 200 mm thick. This means it is very effective in limiting heat loss. This translates into better energy efficiency for buildings insulated with cork, allowing significant savings on energy bills. In addition, cork maintains its thermal performance over the long term, even in variable climatic conditions, making it a durable choice for insulation.