The vapor barrier layer effectively hinders the transfer of water vapor under specific conditions. Factors such as residents, appliances, plants, and plumbing produce moisture that transforms into water vapor in the air. This type of vapor barrier guarantees a high level of vapor breathability in the long term, while simultaneously transforming the bottom surface into a complete waterproof layer (Class W1). It comprises five layers (PP, TL, PP, TL, and PP), and is a fully breathable membrane that can be used in all building components. The product’s durability, breathability, and waterproofness ensure long-term use of the building.