Novia 500 Gauge (125 Micron) Virgin Grade Polythene VCL 2.7m x 50m – 135m²

A vapour control layer (VCL), also known as a vapour barrier, is a material used in building construction to prevent the passage of water vapour through walls, ceilings, floors, or roofs. It is typically installed on the “warm” side of the insulation (typically the interior side) where it helps to control moisture levels within the building envelope. By blocking the movement of water vapour, a VCL helps to prevent condensation from occurring within the building structure, which can lead to issues such as mould growth, rot, and reduced insulation effectiveness.

A vapour control layer should be applied on the interior side of any wall, roof or flooring, over timber studs before the internal lining. It should be 100% sealed to the structure with double-sided butyl tapes, pre-applied to all areas where a fixing is to be made, and finished with metallised BOPP tapes to ensure a complete vapour seal. It is best used in conjunction with a Breather Membrane applied to the exterior side of the structure.