Abstract: Panel including, in succession, a first rigid board forming the back of the panel, a first thermally insulating layer borne by the backboard, an impervious covering covering the first thermally insulating layer, a second thermally insulating layer which partially covers the impervious covering and a second rigid board covering the second thermally insulating layer, characterized in that it includes a film which covers at least part of the impervious covering which is not covered by the second thermally insulating layer, the film including at least one protective portion and at least one spew portion adjacent to the protective portion, the protective portion and the spew portion being able to be detached from the impervious covering independently of one another.

Abstract: Method for testing the sealing of a test specimen (21) comprising a sealing film and two fibrous reinforcing layers, one on each side of the said sealing film, the said method comprising the steps of: connecting the said test specimen to a test bench (22), conducting a first test of behaviour under pressure, subjecting the said test specimen to at least a first thermal shock, and conducting at least a second test of behaviour under pressure, characterized in that the said method comprises at least the steps of: removing the said test specimen from the said test bench after the said first test of behaviour under pressure, and subjecting the said test specimen to the said first thermal shock remotely from the said test bench, and refixing the said test specimen to the said test bench to conduct the said second test of behaviour under pressure.

Abstract: Panel (1) comprising, in succession, a first rigid board forming the back of the panel, a first thermally insulating layer (3) borne by the said backboard, an impervious covering (4) covering the said first thermally insulating layer, a second thermally insulating layer (5) which partially covers the said impervious covering and a second rigid board (6) covering the said second thermally insulating layer, characterized in that it comprises a film (8) which covers at least part of the said impervious covering which is not covered by the said second thermally insulating layer, the said film comprising at least one protective portion (9) and at least one spew portion (11) adjacent to the said protective portion, the said protective portion and the said spew portion being able to be detached from the said impervious covering independently of one another.