Blog

Rob Firman, technical and specification manager at Polyfoam XPS, addresses contractors’ queries about inverted roofs and extruded polystyrene insulation. Why is a different lambda value used for an inverted roof calculation? In simple terms, the ‘declared’ lambda value refers to the thermal conductivity of the product when it leaves the factory. When laid over the […]

Rob Firman, Technical and Specification Manager at Polyfoam XPS highlights the risks of inaccurate U-value calculations and need for a more rigorous approach during the specification process. It’s an unfortunate truth that despite their importance, U-values and their calculation are not as well understood as they should be and that can lead to misleading calculations. […]