Expanded cork

About craft and material

Expanded cork was developed as a natural insulation material, using parts of cork bark that were not previously used.

When the cork oak tree is stripped of its bark, it is usually done only for the trunk while upper branches are left untouched. Bark from the latter cannot be used to make natural corks, as it is not thick or uniform enough and contains too much resin. Instead, it is used to make expanded cork. Once it has been stripped from the tree, it is granulated, placed in a mould and compressed. Then, superheated steam causes the resin held within the cork granules to surface.

This material is much darker than normal cork, because of the resins and it also has a distinctive fragrance that fades over time. This fantastic material is 100% natural and recyclable and it is also water- and fireproof. The list of the advantages of expanded cork extend to stability of its technical parameters over time, excellent and long-lasting dimensional stability, resistance to many chemicals, insects and rodents, and lack of toxic gases released during a potential fire.