Longley Top Sheet insulated flooring system consists of 175 mm deep pre-stressed concrete beams, ‘infilled’ with lightweight expanded polystyrene (EPS) blocks which are supplied in easy-to-handle lengths enabling fast installation. The EPS blocks are available in a range of configurations providing a flexible approach to achieving U-values. The floor is completed with a structural concrete topping reinforced with either polypropylene fibres or steel mesh, laid over a top sheet of EPS insulation