Glasull

Glasull is the common Scandinavian term for glass wool, a fibrous insulating material used in building and other applications to provide thermal and acoustic insulation. It is composed of extremely fine glass fibers formed by melting silica-based glass and drawing it into long, hairlike strands, often combined with a binder to form mats or blankets. Modern glasull products may include recycled glass as part of the raw material and are manufactured in a range of densities and thicknesses, depending on the intended use.

Glasull products are used to reduce heat transfer and improve sound absorption in walls, roofs, attics, floors, pipes, and industrial equipment. They are valued for being lightweight, flexible, non-combustible, and resistant to moisture in fiber form, though the binder and facing materials can affect moisture handling and installation. Some products are faced with foil, paper, or foil-faced paper to provide additional barrier properties.

Safety and handling: During installation, glass fibers can irritate skin, eyes, and lungs if fibers become airborne. Protective clothing, gloves, and respiratory protection are recommended, and installation should follow local building codes and manufacturer instructions. Once installed and sealed behind appropriate facings, glasull generally provides long-term insulation.

Etymology and usage: The term glasull derives from Swedish, where glas means glass and ull means wool. The English equivalent is glass wool or fiberglass. Similar terms are used in Norwegian and Danish.

See also: Glass wool, Fiberglass, Mineral wool.