Foamboard R+ is an extruded polystyrene boards with skin surface. They are used on water proofing membrane for the thermal insulation of flat roofs.
The membrane (bituminous, pvc, tpo, ect.) forming water and vapour proofing is rolled out on existing levelling concrete. Foamboard R+ boards of are laid together without applying adhesive so that the joints are adjusted. Filter element and cover that serves as seperator felt are laid on the boards. For the inaccessible flat roofs, a layer of washed round light-coloured gravel is placed on top of the separator cover in order to put weight and to reflect sun rays. For the accessible flat roofs, precast tiles (concrete, wood, etc.) are placed resting on plastic wedges. If desired, floor coverings applied with sand or grout can be used as well. For the garden flat roofs, the layers including gravel are applied like the inaccessible flat roof. Filter element and plant soil are laid out on the gravel to finish off the process.