How is insulation measured?

Floors, attics and walls all require insulation of different R-Values which are measured by the thickness of the insulation. The R-Value determines how well the insulation will resist heat flow. The higher the R-Value the more resistance it has to heat and cold.

If you are adding to existing insulation there is another factor to consider. You will have to determine the R-Value of the existing to know how much additional insulation to add