Loft insulation is the most common form of roof insulation used today, with mineral fibre being the most commonly used insulation material in this application. However, 33% of homeowners would like an extra bedroom whilst 43% said they did not have enough storage space. With building land at a premium it is often easier to increase a living area “vertically”. The use of rafter level insulation in creating a warm roof space which can then be used for a warm storage area or may be fully converted to a “room in roof” is rapidly increasing. Polyurethane (PUR) and Polyisocyanurate (PIR) insulation products can be used to achieve this.