R-Value Range

R-Value Range

Type

Walls

Interior Walls

Floors

Bsmt / Crawl Spaces

Attics

2X4

2X6

Fiber Glass Batt

R-13

to R-15

R-19

to R-23

Fiber Glass Blow-in

R-13

to R-16

R-20

to R-25

Mineral Wool Batt

R-13

to R-15

R-22

to R-23

Mineral Wool Blow-in

R-14.5

R-23

Cellulose *

R-12

to R-13

R-19

to R-20

Spray Foam Open Cell**

R-12

to R-13

R-19

to R-20

Spray Foam Closed Cell**

R-19

to R-22

R-32

to R-35

* Cellulose R-Values can be overstated due to potential settling over time.

** Spray foam R-Values assume full cavity installations, but full cavity installations with spray foam are difficult to achieve.