R13 insulation is commonly used in exterior walls, floors, and crawl spaces where moderate insulation levels are needed.
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.
Cellulose insulation appears fluffy and usually comes in shades of beige, gray, or tan. Its texture and appearance are similar to papier-mâché, paper pulp, or finely shredded paper, giving it a unique and easily recognizable look.