Thermal insulation and simultaneous gradient formation on the roof of the EPAL Stavroupoli school complex in Thessaloniki with the ultra lightweight thermal insulating mortar Politerm Blu of 200Κg/m3 density and average thickness of 10cm. Upon hardening, waterproofing with bituminous membranes follows along with the application of the white sun reflecting acrylic waterproofing paint Tektoflex.