Which type of insulation is known for a high R-value per inch of thickness?

Spray foam insulation is recognized for its high R-value per inch of thickness, which is a measure of its thermal resistance. This makes it an exceptionally effective insulator, as it can provide superior thermal performance within a comparatively thinner profile. The R-value of spray foam insulation can vary depending on its specific type, but it typically falls in the range of R-5.5 to R-7 per inch.

One of the key benefits of spray foam is its ability to expand upon application, filling gaps and crevices effectively, which minimizes air leaks and enhances energy efficiency. This characteristic not only contributes to its high thermal resistance but also aids in moisture control and sound dampening.

In contrast, other types of insulation have lower R-values per inch. For example, fiberglass insulation generally has an R-value range of approximately R-2.9 to R-4.3 per inch, while cellulose insulation typically offers R-values around R-3.2 to R-3.8. Polystyrene, which is available in both expanded (EPS) and extruded (XPS) forms, generally achieves R-values of R-4.0 to R-5.0 per inch. Therefore, while these materials have their own advantages, none