Horizontal thermal insulation of sills in contact with the ground, with extruded polystyrene

Horizontal thermal insulation of sills in contact with the ground, formed by a rigid panel of extruded polystyrene, with a smooth surface and lateral machining to half wood, 40 mm thick, compressive strength >= 300 kPa, thermal resistance 1.2 m²K/W, thermal conductivity 0.033 W/(mK), placed at the top of the sill, simply supported, covered with a 0.2 mm thick polyethylene film, prepared to receive a concrete sill. Including self-adhesive tape for sealing joints.