Sandwich panels are made up of two thin metal layers and insulation material between those layers. Although usually prepainted galvanized steel sheets are used as outer metal layers, aluminum or other metals may also be used. Infill materials are usually the following, Polyurethane (PUR) foam, Polyisocyanurate (PIR), EPS (Expanded Polystrene) foam and rockwool.
Sandwich panels with their prefabricated nature are very practical roofing and wall materials, providing both heat and water insulation. Also, it provides a great save from workmanship in site.
Sandwich panels for roofing are ribbed due to better mechanical strength. Thickness of sandwich panels are 40mm – 50mm – 60mm – 80mm -100mm, determined by heat insulation requirements and calculations.