The right insulation and underfelt makes a real difference to how well Velux roof window installation projects work. Pay less for your Velux installation products, such as insulation and underfelt, or a vapour barrier, when you buy from Roofing Supplies UK. We stock Velux branded accessories that are designed for use with a Velux roof window. There are a number of different sizes to choose from, all ready for rapid delivery anywhere in the UK. Our team can handle larger orders as well as one-off purchases – use our easy online ordering service to pick the cheap Velux insulation and underfelt products you need.