Insulating values of up to R-15 for 2 X 4 walls and up to R-23 for 2 X 6 walls can be achieved. The ASTM C518 test for the Blow-In-Blanket System states that the R-value is 4.2 per inch, although some manufacturers have the R-value listed as 4.0 per inch (Fig. 9.8).
Figure 9.7 Installing the blow-in-blanket system. (CertainTeed)