This part of ISO 13784 specifies a test method for evaluating the reaction-to-fire performance of sandwich panel building systems for large rooms and the resulting flame spread on or within the sandwich panel building construction when it is exposed to heat from a simulated internal fire with flames impinging directly on its internal corner. The test method is not intended for evaluating a product's fire resistance. This part of ISO 13784 is applicable to both freestanding and self-supporting, and frame-supported, sandwich panel systems, but only to wall and ceiling or roof constructions.