subject: Installing Insulation: Types And Uses [print this page] The kind of insulation you have in your home has a huge impact on the amount of energy you expend. Different types of insulation are suited to different types of construction, and some may need to be installed by a professional. Four of the basic kinds of insulation are batt and blankets, loose fill, rigid board, and spray foam.
Batt and blanket insulation is typically the most affordable insulation and the best choice for a do-it-yourself installation, but it must be inserted carefully. It is made from mineral fiber (rock or slag wool, fiberglass, natural fibers, plastic fibers) and works well in unfinished walls, above ceilings, and in the foundation. It is best in a rafter, joist, or stud spacing of sixteen or twenty-four inches that is largely free of obstruction. The batts and blankets come in widths, thus ensuring a snug fit between the frames. Batts are usually four or eight feet long, and blankets, which come in long rolls, are cut to the specified length. Some batts and blankets come with radiant barrier backings, and both of them have an R-value of about R-3 per inch of thickness.
Loose fill insulation costs more than batt and blanket, but it fills in the spaces more easily and efficiently, thus providing better sound insulation and reducing air leakage. Loose-fill, made of cellulose, mineral wool, or fiberglass, contains fiber pellets which can be blown into nooks and crannies with the right equipment. It's great for adding insulation to areas that are already finished or are irregularly shaped and hard to get to. Cellulose insulation is treated for moisture and fire resistance and has thirty percent more insulating value; fiberglass and mineral wool insulations can be installed with a Blow-in-Blanket System (BIBS). Loose-fill has an R-value of R-3 to R-4 per inch.
Rigid board is good for unfinished walls, ceilings, and foundations and flat roofs. It's made of polystyrene, polyurethane, or fiberglass and must be covered with gypsum board (half-inch) to be used in the interior, weather-proof facing for the exterior. It has a high insulating value for a relatively low thickness: R-4 to R-8 per inch.
As spray foam is sprayed in a liquid (polymer) form into walls, ceilings, and floors, it expands into a solid plastic with air-filled cells. It works well for finished areas, particularly irregularly shaped ones, but should be installed by a professional. Spray foam is usually a more expensive option, but it eliminates the need for caulking and other detailing.
The type of insulation you use will depend on where you need to put it.
