Attic insulation should be about 10 to 14 inches deep, achieving an R-38 level, depending on the insulation type.
The thickness of R38 batt insulation is usually about 12 inches. This substantial thickness helps to provide excellent thermal resistance, making it a popular choice for insulating attics and other areas where maintaining a high level of energy efficiency is crucial.
To cut fiberglass insulation, use a sharp utility knife and a straightedge to ensure a clean, straight cut.