R-Value

This indicates a material’s amount of resistance to heat transfer. The higher this number, the more insulation the product provides. Other factors to consider when looking at R-Value are assembly, thickness, and location.

• Assembly: To increase the accuracy of insulation’s R-value the entire assembly (exterior and interior walls as well as insulation material)is sometimes considered. But for most consumers calculation at this level is not necessary.
• Thickness: A common misconception about the R-Value is that the thicker the insulation material, the more efficient it is. While the R-value may increase as the amount of insulation increases, there is actually a decreasing return in terms of efficiency. For example, fiberglass batting with an R-value of 3.3 increases to an R-value of 6.6 when the amount of material is doubled, however, the efficiency does not double in the same way.
• Location: Building codes in different parts of the country call for different R-values. Fuel and material costs as well as climate conditions determine these varying insulation needs.