There are a variety of different types of insulation, each with their own unique properties.

Insulation is a material that prevents heat or sound from passing through it. It is typically used to keep heat and/or sound in or out of your home or to limit it to specific areas of your home. Insulation can function in a variety of ways, but it is most commonly comprised of materials that contain millions of tiny pockets of air. Still air is an excellent insulator, and trapped pockets of air are responsible for most types of insulation having a high thermal resistance.

Types of Insulation

Blanket insulation (batts and rolls)

Blanket insulation is one of the most commonly used types of insulation and is available in batts or rolls. Batt insulation comes in pre-cut panels. Insulation in continuous rolls can be cut and trimmed to fit the area you need to cover. Fiberglass batts and rolls are common, but minerals (rock and slag) and other materials can also be used. 

Blanket insulation is typically installed in unobstructed areas such as unfinished walls, floors, and ceilings. It is often used in new construction projects and is installed between joists, studs, and beams.

In addition to providing thermal insulation for spaces inside the home, blanket insulation is frequently used in attics and as acoustical insulation for commercial buildings.

Concrete block insulation

It is possible to insulate a block wall from within, believe it or not. Filling the gaps between the concrete blocks with insulation can make a difference in energy consumption, sound transfer, and comfort within the space as long as the gaps remain accessible.

Generally, spray foam, loose-fill mineral wool or polystyrene beads are suitable materials for concrete block insulation. By filling up the wall cavity at the bottom, these materials will stop air and sound from passing through the wall. There are also expanded polystyrene (EPS) blocks that are cut to fit inside a concrete masonry unit’s cavity (CMU). However, some of these materials aren’t easily accessible, so it’s usually best to leave the job to a pro during the building process. 

Best for: New concrete block walls in new construction.

Loose-fill insulation, blown-in insulation

Loose fill insulation, also known as cellulose, is a type of blow-in insulation that is commonly used in attics and other horizontal structural spaces. Typically, cellulose is made from recycled newspaper or denim. The cellulose is then sprayed with a chemical that prevents pests and bugs from burrowing through and making a home. 

Typically, cellulose is blown into an open attic floor or similar space by installers. However, DIYers can spread bags with gloved hands in small areas if necessary, as long as they fluff up the settled cellulose to achieve the lofty texture. It will not insulate as well if it is overly compacted.

Radiant barriers

Radiant barriers are constructed from heat-reflective materials.

It is made of a foil-like material that, when facing inward, reflects heat back into your home and, when facing outward, reflects heat away from your home, reducing your air conditioning costs.

Rigid foam or foam board

Foam boards and rigid foam panels can be used to insulate a floor or an unvented low-slope roof. They reduce the amount of heat that is conducted through wood, wall studs, and other structural elements of a home.

This kind of of insulation, which is typically made of polyurethane, polystyrene, or polyisocyanurate, is used by many homeowners for both the exterior and interior wall sheathing. Everything from basement and foundation walls to unfinished floors and ceilings can be insulated well with foam boards. R-values for foam boards and rigid foam panels typically range between R-4 and R-6.5 per inch of thickness, indicating that they reduce energy consumption better than some other types of insulation on the market.

Sprayed-foam insulation, foamed-in-place insulation

Spray foam insulation fills gaps and seals leaks inside existing walls. Spraying liquid polyurethane into the wall cavity causes it to expand and solidify into foam. Homeowners can use pressure-sprayed (foamed-in-place) foam insulation when working with a larger area.

There are two types of spray foam: open-cell foam and denser, closed-cell foam. Although it can be pricey, closed-cell foam has one of the highest R-values of any insulation, at about R-6.2 per inch. The R-value of open-cell foam insulation is around R-3.7 per inch of thickness. Since installation can be more difficult than simply aiming and spraying, it is advisable to hire a professional when using spray foam to increase the R-value of a home’s insulation. However, determined DIYers with a DIY kit can complete this task on their own.

Structural insulated panels

The structural insulated panel is an innovative type of wall insulation.

This prefabricated material is made of polystyrene foam sandwiched between boards. When constructing a building, they fit together to create the walls and floors.

Materials Used in Insulation

There are many different types of insulation materials, such as fiberglass, mineral wool insulation, cellulose insulation, natural fiber insulation, and many more.

Fiberglass

Fiberglass is the most commonly used insulation material in loose-fill and blanket insulation. It is also used in rigid boards and duct insulation. Manufacturers are now producing medium- and high-density fiberglass batt insulation with R-values slightly higher than standard batts.

Mineral Wool Insulation Materials

Mineral wool has an average of 75% post-industrial recycled content. This insulation material does not need additional chemicals to make it fire-resistant. Mineral wool is commonly used in blankets and loose-fill insulation. Mineral wool is classified into two types: rock wool and slag wool.

Cellulose Insulation Material

Cellulose insulation is made out of recycled paper products, particularly newsprint. It is used in both old and new buildings, as densely packed insulation in building cavities such as cathedral ceilings and walls, and as loose-fill insulation in open attic installations. Additionally, it is used in new buildings by installing dry behind netting or damp-spraying it. Cellulose insulation has an R-value of 3.6–3.8 per inch.

Plastic Fiber Insulation Material

Recycled plastic milk bottles are the primary raw material used in the production of plastic fiber insulation material. The fibers are made into batt insulation in the same way that high-density fiberglass is. Although the insulation is fire resistant due to the fire retardant treatment, it melts when exposed to flame. The R-values of batts vary with density, ranging from R-3.8 per inch at 1.0 lb/ft3 density to R-4.3 per inch at 3.0 lb/ft3 density.

Natural Fiber Insulation Materials

Insulation can also be made from natural fibers such as hemp, straw, sheep’s wool, and cotton. Cotton insulation is nontoxic, but it is more expensive to insulate than fiberglass batt insulation. Cotton and sheep’s wool have R-values of 3.4 and 3.5 per inch, respectively. Straw boards can also be used to make sound-absorbing panels for interior partitions.

Polystyrene Insulation Materials

Polystyrene is widely used in the manufacturing of concrete block insulation, beadboard or foam board insulation, and a type of loose-fill insulation composed of small polystyrene beads. Polystyrene insulation materials on the market include expanded polystyrene (EPS), molded expanded polystyrene (MEPS), and extruded polystyrene (XPS). The R-value depends on the density of the material and ranges from R-3.8 to R-5.0 per inch.

Polyurethane Insulation Materials

Polyurethane is a type of foam insulation material made up of cells that contain a low-conductivity gas. Because of the high thermal resistance of the gas, the R-value of this insulation material ranges from R-5.5 to R-6.5 per inch. It is available in both closed-cell and open-cell formulations. 

The insulation material has a spongy texture and a lower R-value due to the open-cell foam cells’ low density and air content. In contrast, closed-cell foam has a high density and a gas inside that allows it to expand to fill the surrounding space. 

Polyurethane insulation is available in rigid foam board and liquid-sprayed foam forms. It is also available with different facings as laminated insulation panels.