Novia 500 VCL is a low-cost, blown polythene material, suitable for use as a vapour control layer within the walls of timber frame constructions, or where control of the passage of water vapour is required. This product also performs the additional function of an air-leakage barrier, to prevent losses due to unwanted convection flows. We advise the use of Novia double sided butyl and metallised BOPP tape to ensure a complete barrier integrity throughout the entire life of the product. For difficult areas to seal with tapes, or for additional support in certain applications, Novia AirSeal 310 is available. Novia 500 VCL should be used in combination with Novia breather membranes to provide an air-tight and vapour resistant system. Novia 500 VCL is fully CPR compliant and is UKCA Approved to EN 13984.