When you think about adding insulation to your home, the image that usually comes to mind is long strips of fiberglass insulation in faced batts or unfaced rolls. Batts of faced fiberglass insulation is the standard material used to insulate wall and joist cavities during new construction, and improving the insulation in attics often involves laying a "blanket" of unfaced fiberglass rolls across the attic floor.
But fiberglass batts and rolls have limitations for retrofit applications, and homeowners are wise to consider blow-in insulation as an alternative for improving the home's insulation R-value. R-value is the industry standard for measuring the resistance value of specific insulating materials; the higher the R-value, the better the material insulates.
The term blown-in insulation (or loose-fill insulation) refers to the process of filling stud or joist cavities or covering attic floors, with any loose material that has a good insulating R-value. There are a variety of materials that can be used, the most common materials include loose fiberglass and cellulose material.
Blown-in insulation offers a much faster way to significantly improve your attic insulation. In a matter of an hour or two, an installation specialist can blow a thick blanket of loose insulation across the floor of the attic using a single hose run up through the attic hatch. For wall cavities, blown-in insulation is the only practical way to improve the R-value of stud cavities, short of removing entire wall surfaces to install faced fiberglass batts.
Blown-in cellulose insulation is a favorite among homeowners who prefer green products, since the material is made entirely from recycled paper and wood products, with few synthetic processes or chemicals involved.