Insulating roofing panel - has layer contg. skin free of bitumen and completely impermeable to it

摘要

The insulating roof panel comprises a layer of hard plastic foam with a top cladding contg. perforated and unperforated layers held against each other by a further layer on one side, extending through the perforations to adhere to the unperforated layer on the other side. The topmost of the perforated or unperforated layers incorporates a skin contg. no bitumen and absolutely impermeable to it or similar roofing material when in the liq. or soft state, even when liquefied by heat. Outside the perforations this top layer is completely free of the lower one glued to the one of plastic foam.