Typical Types of Insulation
Loose fill. Fiberglass is the most common loose fill material. Loose fill is preferred by insulation contractors for finished wall spaces, attics, and hard-to-reach areas, because it can be blown in. This type of insulation is relatively inexpensive, and many cellulose-based varieties are made with up to 80 percent recycled materials. Loose fill insulation is often used to retrofit older homes.
Blankets. Fiberglass blankets are usually precut into either rolls or batts. Batts are sheets specifically sized to fit between wall studs. They are typically used during the building process to insulate walls before sheetrock is hung. Fiberglass rolls are commonly used to insulate basement or crawl space ceilings.
Spray Polyurethane Foam. Spray Polyurethane Foam (SPF) is a mixture of two components that form a dense but expanding material, which can be sprayed into walls and crevices, on concrete slabs, or on the interior side of wood sheathing. The foam is highly mold-resistant, cannot be damaged by water, and can easily be injected into irregular spaces. The foam also meets air barrier requirements in building codes, without the use of additional materials.
SPFs are usually classified as either an open-cell foam or a closed-cell foam. Closed-cell foam is stronger and has a somewhat higher R-value than open-cell foam. Because of its higher density, much more of the material can be needed to complete certain types of projects, thereby significantly increasing cost. In many instances, open-cell SPF can still provide the same insulating and vapor-controlling properties.
One downside of spray foam insulation is that the initial cost is significantly higher than most other insulation materials. Also, the foam will tend to lose a little of its R-value over time; however, the process stops when it achieves equilibrium with the surrounding environment, and the R-value will still remain very high compared to other types of insulation.
Radiant barrier or reflective insulation. Radiant barriers are foils, films, or paints engineered to reflect radiant heat back in the direction from which it came. Radiant barriers can be installed in a number of areas in the home and are commonly installed in the attic. The radiant barrier foil is typically stapled to the underside of the roof rafters, while in paint form it is applied directly to the underside of the roof decking.