The four prevalent insulation materials are fiberglass, spray foam, batting, and loose-fill cellulose.

The choice of insulation should be guided by its intended application area, the insulation's R-value goals, and your financial plan.

For exterior walls, R-values range between R-13 and R-23. Ceilings and attics often require higher R-values, typically R-30, R-38, or R-49.

Closed-cell foam insulation acts as a vapor barrier, enhancing the structural integrity of the application area and featuring a denser, more even surface. It offers high R-value even with thinner layers. Open-cell foam, while providing similar R-value benefits, differs in that it doesn't serve as a vapor barrier but excels in sound dampening. It tends to have a less even surface and fills larger spaces more effectively.