Compiled by Juli Case
What is R value?
R value has to do with a material’s resistance to heat flow and is most often referenced with relation to insulation, although it is also used with some interior fabric applications such as draperies and carpet. R value is the ratio of the thickness of a material to thermal conductivity. Essentially, the higher the R value, the greater the insulating effectiveness of the material. If you’re assessing the R value of an assembly, it is possible to add the R values of the component materials.