Roof: For the roof ,our cases is PU foaming (45kg/m3 which meets standard of PIR)which has high integarity for the airtightness which would be better than common EPS sandwich panel or glass wool as roof insulation.
Panel: For the sandwich panels,we remarks with density and thickness of both sides of steel sheets,in the same time,you can find the treatment with Aluminum zinc magnesium AMZ galvanized 100g/m2 with PE baking finish 20/5um. which can last more than 25 years.