Foam boards are highly effective for insulating exterior walls, basement walls, attic hatches, and other parts of your home.
Attic insulation levels are measured by R-Value, which indicates resistance to heat flow. Most attics should be insulated to R-38, or about 10 to 14 inches, depending on the insulation type.
R-Value measures insulation’s ability to resist heat flow, with higher R-Values indicating better thermal performance.