R-value requirements also vary based on the spot in your home in which the insulation is installed. When it comes to the best insulation for walls, the insulation material can also impact the R-values needed for good energy efficiency.
Insulation Materials
Fiberglass: Fiberglass is the most common insulation material. It’s made from fine glass fibers and is most often used in batts, rolls and loose-fill insulation. Fiberglass is a skin and lung irritant, so always wear protective eyewear, gloves, masks and clothing when working with fiberglass insulation.
Cellulose: Cellulose insulation is made from recycled paper products. Manufacturers also add borate for fire and insect resistance. Cellulose insulation is usually a loose-fill insulation.
Foam: Foam insulation may be made from polystyrene, polyisocyanurate or polyurethane, which are all types of plastic. You can also install cementitious foam insulation, which is cement-based. Foam insulations can be sprayed or installed in rigid foamboards.
Mineral wool: Mineral wool can refer to either rock wool or slag wool. Rock wool is a man-made material made from a combination of natural minerals. Slag wool is also a man-made material but is made from a waste product of molten metal known as slag. Both mineral wool insulations are naturally fire-resistant. They come as batts, rolls and loose-fill.
Natural fibers: Insulation can also be made from various natural materials, including cotton, sheep’s wool, straw and hemp. Typically, these materials are from recycled sources and are treated to be fire, mold and insect resistant.
Denim insulation is made from recycled jeans and post-industrial denim cotton. Denim is non-toxic and non-irritating, making it easy for DIYers to install. It’s typically more expensive than fiberglass or other insulation materials.
The most common insulation materials are fiberglass, cellulose and foam. Home insulation types include any of the above materials in the form of loose-fill, batts, rolls, foam board, spray foam and radiant barriers.
Loose-Fill Insulation
Loose-fill insulation, also known as blown-in insulation, is blown or sprayed into place with special equipment. You can rent an insulation blowing machine to install this insulation yourself, but most choose to leave this installation to professionals.
Best for attics, hard-to-reach or oddly shaped areas and already insulated areas.