U-Foil Polyethylene Foil Bubble Insulation - 1200mm x 25m x 4mm (30m2) Description U-Foil 1BDA insulation comprises of polyethylene bubble which has aluminium to either face. It's available in two specifications - Class '1' Surface Spread of Flame and Class '0' to Building Regulations. U-Foil thermal performance is unaffected by moisture and condensation, it has a vapour resistance in excess of 500MNsg and will therefore provide significant resistance to the passage of water vapour, and would be considered a vapour control layer as defined in section 1 of BS5250:1989 (1995). U-Foil 1BDA is a high performance insulation material that is manufactured from recognised high performance components. The bubble is manufactured from 90 grade polyethylene for the single bubble and from 180 grade polyethylene for the double bubble. The aluminium foil used in all instances is 12 microns and this has a protective NC coating applied to it which gives the product durability and resistance to corrosion.