Foolad Gharb “Economy Sandwich Panel” being patented, is produced with polyurethane insulation core in thickness range from 2 to 15 cm. In the production of this panel, the top face is layered with pre-painted galvanized iron, while waterproof paper or reinforced Alu-foiled kraft paper comprises the bottom layer. The type of waterproof paper used in the one-sided paper sandwich panel, in addition to its remarkable resistance to water penetration, eliminates the possibility of insects nesting and shows high resistance to pressure and impact. This type of panel, which at the same time has the main features of a sandwich panel is considered a light-weight, economically affordable and a cheap option due to the usage of thin insulation core and the substitution of the bottom skin-layer with waterproof paper or Alu-foiled kraft paper. Hence, Foolad Gharb Economy Panel can be considered a suitable alternative for covering all kinds of roof structures, such as roofing sheets. Also, the installation of this product is much easier and faster than roofing sheet which in most cases requires an insulation layer such as glass wool. Foolad Gharb Economy Sandwich Panel is the best choice for applications the same as warehouses, for which the thermal insulation is not case.