These are made using a layer of insulation between two metallic panels, and are used to insulate buildings. For modular structures, 2 types of sandwich panel are most frequently used:
- a version comprising sheet steel panels separated by polyurethane foam. This has the advantage of a light weight and good insulation properties.
- a version with an insulating core made from mineral wool. This provides better fire protection, but requires a greater thickness in order to provide the same insulation coefficient.
Note: Also available are sandwich panels with a perforated inner metal sheet, used to improve building acoustics.