There is no “one” answer to the question of how much insulation your home needs. The short answer is that your home needs enough insulation to properly protect it. There is a lot more involved in determining how much insulation your home needs. Your climate is the biggest factor that determines how much insulation your home needs, followed by local building codes, air leakage, your home’s construction and so on.
In a cold climate like Michigan, a higher R-value is required than would be necessary in warmer climates. Attic insulation in Grand Rapids, Michigan should be an R-value of R-48 to R-60. How thick this should be depends upon the type of insulation that is installed (e.g., fiberglass versus spray foam).
When adding insulation consider sealing air leaks in addition to insulating. Insulation creates a thermal blanket that helps reduce heat transfer. This thermal blanket helps keep conditioned inside air from escaping the home. This thermal blanket may not prevent all conditioned air from escaping. Traditional insulation materials such as fiberglass insulation and cellulose insulation are porous materials that allow some air flow, not to mention the air gaps around the insulating material. Sealing air leaks around wiring, duct work, etc. is an important step to help keep even more conditioned air in your home. Spray foam insulation is a unique product that insulates and seals air leaks in one step.
If you have questions about adding insulation to your home, call us at Whitson Insulation and we can help.