The application of expanded cork board in the insulation of double walls (air gap) provides excellent thermal insulation for a long time period plus suitable acoustic comfort.
Double walls with an air gap tend to create serious problems with dampness which is why it is of paramount importance to create a groove at the bottom of the air gap, on the slab, with an outlet to the exterior, thereby creating ventilation of the air gap which, along with the barrier caused by the expanded cork board, eliminates any dampness problems.