definition
strict definition
perlite loose fill
Loose expanded perlite particles used as thermal insulation, made by heating naturally occurring volcanic glass.
Perlite loose fill is a thermal insulation material made from expanded grains of perlite, a naturally formed amorphous (non-crystalline) volcanic glass which expands when heated. It typically contains high levels of silicon oxide and aluminum oxide. It is generally light in color, usually white or yellowish.
Heating expands the perlite into lightweight porous particles. The pores reduce the bulk density of the resulting loose insulating material.
The particles remain loose within the space being insulated. Perlite incorporated into a bonded board or another manufactured assembly has a different material form.
Related definitions
-
cellulose loose fill
Particles or loose pieces of organic plant fiber used as thermal insulation. -
fiberglass loose fill
Glass fibers stuffed loosely into wall or roof cavities for thermal insulation. -
granulated cork
Granules of cork-oak bark used as loose thermal insulation in wall or roof spaces. -
hemp loose fill
Loose hemp fibers packed into wall or roof cavities as thermal insulation, generally from low-psychoactivity plant varieties. -
mineral wool loose fill
Unbound mineral fibers used as loose thermal insulation, including rock wool and blast-furnace slag wool. -
straw bales
Bales of straw from grasses such as wheat or rice used as thermal insulation within a building assembly. -
vermiculite loose fill
Loose expanded particles of vermiculite mineral used as thermal insulation in building spaces.