How much total R-value does approximately 6 inches thick of loose fiberglass insulation provide?

Loose fiberglass insulation typically has an R-value of about 3 to 4 per inch of thickness. When you consider a thickness of approximately 6 inches, you can estimate the total R-value by multiplying the thickness by the R-value per inch.

For loose fiberglass insulation, a common average R-value is around 3.5 per inch. So, if you multiply 6 inches by 3.5, the calculation yields a total R-value of approximately 21. However, in practical terms, many manufacturers and building codes reference a range; thus, you might see that 6 inches yields an R-value in the ballpark of 18.

This is why the total R-value for 6 inches of loose fiberglass insulation is correctly considered to be 18, as it aligns with the prevalent values used in insulation standards, ensuring that you understand the insulation's effectiveness in resisting heat flow.