InterNACHI Home Inspector Practice Exam

Fiberglass is recognized for its superior insulation properties in comparison to natural materials like wood, cotton, and straw. Its structure consists of fine glass fibers that trap air, which is essential for effective thermal insulation. This design allows fiberglass to have a higher R-value, meaning it has a greater resistance to heat flow.

While natural materials such as wood, cotton, and straw may offer some insulation benefits, they often do not reach the level of efficiency that fiberglass provides. For instance, wood can conduct heat more readily, and although cotton and straw have insulating qualities, they are typically not engineered for insulation purposes at the same effectiveness. Therefore, fiberglass is often the preferred choice in both residential and commercial insulation applications due to its balance of performance, cost, and durability.