CoolRoof solution is not a waterproof solution. On the other hand, our solution is impermeable to liquid water. Indeed, it has been tested by an external laboratory according to the NF EN 1062-3 standard and has been classified W3 according to DTU 42.1, the most waterproof class. Moreover, the CoolRoof solution is permeable to water vapor (tested according to NF EN ISO 7783-18 and classified V2 according to DTU 42.1), which is an important property in some applications to avoid moisture problems in buildings (perspirance property of the walls preserved).