Common Insulation Types 
Blankets and batts: Batts are precut panels in standard widths and lengths to fit inside studs spaced 16" or 24" on center, and walls 8 ft. or 9 ft. high. Some manufacturers offer batts with vertical seams that make tearing the batts to fit much easier. Blankets are rolls of insulation that are more efficient when you need to fill long spaces. Both styles are available in fiberglass, spun mineral wool, recycled plastic, and natural fibers. Fiberglass batts are the most common and least expensive type, and are lightweight and easy to work with. Blankets and batts come faced or unfaced, in a wide range of R-values.
Loose fill: As the name implies, this is particulate insulation that is blown into walls and other spaces. Fiberglass and mineral wool are usually blown in dry, while cellulose insulation—shredded bits of paper and cardboard added to water, flame-retardants, and other chemicals and fillers—may be blown in wet or dry. Loose fill is ideal for tight and unusual spaces that are difficult to insulate with batts. R-values vary depending on how the material is prepared and how it is blown in, and the spraying of loose fill is generally best left to professionals.
Spray foam: A combination of polymer and foaming agent, this insulation is mixed on site by special installers and sprayed into walls, floors, and ceilings. The foam expands and solidifies, forming a plastic barrier with millions of air pockets. Foam is more expensive than other types of insulation. But R-values are generally higher and there’s no air movement, so overall performance is better. The process is quick, and foam does not need a vapor barrier.
