What is a vapour control layer and where is it installed?
A vapour control layer is a vapour tight membrane that is installed on the warm side (facing towards the liveable area) of a roof or on the inside of the exterior house wall. The function of a vapour control layer is to avoid moisture that builds up inside a house, tol find its way to the insulation material, which then will absorb the moisture making the insulation material lose its ability to insulate. If a vapour control layer is installed in a wall, it must be a light construction, meaning that the inside wall of the house should be made from wood, gypsum or similar light weight building materials for walls. Why use a vapour control layer? Not many are aware of why the vapour control layer (VCL) is so essential. Consider what happens when warm and cold air meets and what will this mean for the building physics in winter and summer climate. When warm air meets a cold surface condensation occurs and water/moisture starts forming, this is what you normally see on a cold glass on a war
