An insulating panel in sintered expanded polystyrene (EPS), available in white and with improved thermal conductivity (graphite), to which a high impact laminated polystyrene (HIPS) film is coupled, obtained through a thermoforming process. The thermoformed film makes it possible to create retaining knobs with reduced height (18 mm) that guarantee rapid installation and safe locking of the piping and are suitable for pipes with diameter 14, 16 and 17 mm. It improves the mechanical resistance of the system and consequently the walkability during construction phases, and acts as a vapour barrier in the operating phase.

The film is also shaped on the perimeter edges in such a way as to allow adequate overlap and a solid connection between adjacent panels, ensuring optimal sealing during the installation of the panels and the casting of the screed.