A sealing device includes a polymeric carrier layer having a first and a second major surface and a first functional layer including 25-95 wt.-% of at least one polymer P1 and 5-75 wt.-% of at least one solid filler F, wherein the polymeric carrier layer has a thickness of 10-450 μm and wherein the sealing device has a mass per unit area of not more than 450 g/m2. A method produces a sealing device, and a sealing device is used as a waterproofing membrane, vapor barrier, vapor retarder, gas barrier membrane, volatile organic compound (VOC) barrier membrane, or as a geomembrane.