A conventional terrace or rooftop is the one where the thermal insulation is installed under the sealing layer and is protected by it. The opposite goes for the inverted roof where the thermal insulation is installed on top of the sealing layer. Most roofs made today are the inverted type due to the fact that they contribute to a greater lifespan of the sealing layer as they are protected from solar radiation, thermal variations (contraction/expansion) and mechanical loads.
In any case, the sealing material selected must have the proper strength to withstand loads due to the terrace’s patency and low water absorption.
The Styropan insulating materials recommended for this application are either STYROPAN XPS R&F extruded polystyrene panels or STYROPAN EPS 150 / 200 white expanded polystyrene panels or STYROPAN GRAPHITE EPS 150 / 200 graphite expanded polystyrene panels.