A referendum to place the duties of the Recorderâs Office into the County Clerkâs Office was passed by the voters of McLean County on November 6, 2012 and took effect December 31, 2013.
Depending on where you live, itâs recommended that attics have a minimum R-value of R-30 in warm climates to R-60 in cold climates. Recommended Insulation by Climate. By dividing the recommended R-value for your area by the R-value of your particular type of insulation, you find that an attic should have on average: Warm Climates (R-30 to R-49): 1  Fiberglass (blown): 14â â 18â. 2  Fiberglass (batts): 11â â 14â. 3  Cellulose (blown): 11â â 13â. 4  Rock Wool (loose): 12â â 18â. 5  Foam (sprayed): 5â â 11â.
What you really need to know is the R-value of the material. R-value measures resistance to heat flow. The higher the R-value, the higher the resistance will be. If the insulation is blown fiberglass, that 13 inches may be R-30. If it's cellulose, that 13 inches may be as much as R-45.