|1. Multiply attic length times width to determine total square footage to be installed.
2. Measure the distance between joists to determine correct insulation width for the job (15� or 23�).
3. Choose appropriate insulation product (R-value and width) for your home insulation project. (Choose insulation product width to match distance between joists � 15� to 16� or 23� to 24�.) If joist cavity is full, insulation width makes no difference because you will install new insultion across and on top of the joists.
4. Divide total square footage to be installed by square footage per package, then round up to the next whole number to determine total number of packages required.