Without the right insulation R-values, hot and cold air alike can flow right through a home’s flooring, walls, ceilings, and attic. But what exactly is R-value, and what does it have to do with ...

Typical R-value: R-3.8 and R-6.8 per inch of thickness, depending on the type. Where commonly used: Basement and crawl space walls, and as continuous insulation on a house’s exterior.