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.
The R-value of loose fill cellulose is R-3.2 to 3.8 per inch 2. Loose fill fiberglass has an R-value of R-2.2 to 2.7 per inch 3. Achieving the desired R-value depends on both the depth of the insulation and its density. Insulation depth Depending on your climate, energy codes require varying R-values for ceiling insulation.