Water vapour permeability ISO 7783-1 | What is water vapour permeability ISO 7783-1?
When painting an external wall, it is very important that the paint protects the wall from water and rain, but it is also important that the wall continues to ‘breathe’, i.e. remains vapour-permeable. The vapour permeability of a coat of paint is tested in the laboratory in accordance with the ISO 7783-1 standard.