Water vapour diffusion is the process of water vapour moving through the building envelope as a result of the difference in partial pressure of water vapour between the internal and external environment. This phenomenon occurs spontaneously, independent of air movement, and affects most building materials to varying degrees.
The intensity of water vapour diffusion depends on the properties of the materials. These include the diffusion resistance coefficient, the thickness of the layers and their arrangement in the envelope. The temperature and humidity conditions on both sides of the envelope are also important. These influence the direction and rate of water vapour transmission.
Correctly shaping the diffusion of water vapour is important to reduce the risk of interstitial condensation and dampness in partitions. As manufacturer of modular homes, we know that it is taken into account in the design of buildings through the selection of materials and the correct layering. Solutions are also used to regulate the flow of water vapour, which has a direct impact on the durability of the structure and the comfort of the house.
