If R-19 insulation is placed on top of R-30 insulation, what is the total R-Value of the two?

When calculating the total R-Value of insulation layers, you simply add the R-Values of each layer together. R-Value is a measure of thermal resistance, and in the case of insulation, more is generally better for energy efficiency and regulating indoor temperatures.

In this scenario, R-19 insulation is placed on top of R-30 insulation. To find the total R-Value, you add:

R-19 + R-30 = 19 + 30 = 49.

This total of 49 reflects the combined resistance to heat flow provided by both layers of insulation. Effective insulation is vital in multifamily buildings for maintaining comfort and optimizing energy use, as it reduces the demand for heating and cooling systems. Thus, the total R-Value being 49 indicates a significantly improved insulation performance compared to either layer alone.