Monthly Archives: September 2018
One of the most commonly used, and widely recognised, acronyms in construction is VCL, which stands for vapour control layer. A VCL is a critical building component designed to protect the building from potential degradation (or poor performance) by managing the passage of water vapour within a building structure. In other words, it is used to manage condensation risk. Condensation is formed when warm moist air condenses into a liquid on contact with a colder surface. A vapour control layer is typically installed on the internal side of the insulation to control the passage of warm moist air (water vapour) entering the structure. However, as a simple acronym, there is a problem because in most applications a specific level or type of performance is required, as a ‘catch all’ acronym VCL is wide open to error.