A: The R-value per inch can be calculated by dividing the R-value at a given thickness by that thickness. For example, R19 is achieved at 8.2 inches, so R-value per inch is 19/8.2 = 2.3.
A: The blown in insulation should reach on average of 10'.
A: This will be something you will need to discuss with your local store.
A: Please refer to the attic coverage chart: https://www.jm.com/content/dam/jm/global/en/building-insulation/Files/BI%20Data%20Sheets/Resi%20and%20Commercial/JM_BIC-262-Attic-Protector-Data-Sheet.pdf R38 covers about 51sq ft per bag; 1200/51 = 24 BAGS