Fiberglass Insulation

Fiberglass insulation is a lightweight thermal insulation material made of fine glass fibers, typically produced as batts, rolls or loose fill, that trap air within the fiber matrix to slow heat transfer through a building envelope. The material, commercially known as glass wool, was invented between 1932 and 1933 by Games Slayter, with the first commercial production following in 1936. Commercialized in the United States from the 1930s onward, it became the dominant residential insulation material across North America through the twentieth century for its low cost and ease of installation between standard wood or metal wall studs and roof framing, though it offers less fire resistance than mineral wool and requires careful installation to avoid gaps that reduce its insulating performance.