Pocketed Polystyrene insulation panels have pre-cut channels for pipe and evenly spaced pockets allowing screed to flow around the pipe. Panels can be placed over a solid floor slab, before pipe installation and screeding. UnderfloorHeatingSystems Hep2OUnderfloorHeating&Cooling, Hep2OUnderfloorHeatingandCooling, Hep20UnderfloorHeating&Cooling