How do aluminum sheets compare to other commonly used materials in building insulation?

Aluminum sheets are lightweight and have excellent thermal conductivity, which can be both an advantage and a disadvantage in insulation. They reflect heat well, making them useful in radiant barrier applications, but they are poor insulators as they do not trap heat. In contrast, materials like fiberglass, cellulose, and mineral wool have lower thermal conductivity and are more effective at reducing heat transfer. These materials are better at insulating as they trap air, which is a poor conductor of heat. Foam insulation, such as polyurethane and polystyrene, also offers good thermal resistance due to their closed-cell structure. Overall, aluminum sheets are not typically used as primary insulation but can be effective in specific applications where heat reflection is desired.