R-value
A measure of resistance to heat flow under stated conditions, thickness and unit system.
Also called: thermal resistance
Material family: Construction, roofing and geosynthetics
Where it matters
Comparing insulation declarations for the project.
Testing and verification
Do not compare values with different units, thicknesses or reporting conditions as though they were equivalent.
Related guides
Related products and materials
Technical references
General information for preliminary evaluation; not independently reviewed or certified. Confirm grades, standards and suitability with the manufacturer for your application. Interpret within the exact material, grade and test method.