Roof insulation significantly reduces thermal dispersions. For model Greca insulating panels in expanded isopolystyrene are available in 20 mm thickness and in a standard size 1000×2000 mm. Insulation panels should be laid under Cover Life roofing sheets according to the direction of installation. Isopolystyrene panels contain a percentage of graphite which increases considerably the insulating capacity. They are resistant to aging and deterioration and have an optimal dimensional stability; they grant for thermal and acoustic insulation over time and energy saving. They are permeable to vapor and strongly waterproof. Insulating panels are easy to lay and when cut they do not release irritating powders.