What is the basic difference among fiberglass, rock and slag wool, cellulose, and foam insulations?

Fiberglass is made from molten sand or recycled glass and other inorganic materials under highly controlled conditions. Fiberglass is produced in batt, blanket, and loose-fill forms.

Rock and slag wool are manufactured similarly to fiberglass, but use natural rock and blast furnace slag as its raw material. Typical forms are loose-fill, blanket, or board types.

Cellulose is a loose-fill made from paper to which flame retardants are added.

Foam insulations are available as rigid boards or foamed-in-place materials that can fill and seal blocks or building cavity spaces. Foams are also used in air sealing to fill gaps, cracks, or openings.

Reflective materials are fabricated from aluminum foils with a variety of backings such as polyethylene bubbles and plastic film. Reflective insulations retard the transfer of heat; they can be tested by the same methods as mass insulation and therefore assigned an R-value.

A Radiant Barrier is a building construction material consisting of a low emittance (normally 0.1 or less) surface (usually aluminum foil) bounded by an open air space. Radiant barriers are used for the sole purpose of limiting heat transfer by radiation.