nountrademark in UK
Inorganic material made into matted fiber used especially for insulation or soundproofing.
- ‘Pack gaps around an insulated chimney with unfaced rock wool or unfaced fiber glass insulation.’
- ‘The European company produces a mineral wool insulation containing equal amounts of rock wool and slag wool.’
- ‘Pipes for kitchen stoves, wood stoves, and furnaces should only be insulated with fiberglass or rock wool because cellulose may smolder if flue temperatures become hot enough.’
- ‘Loose-fill insulation, usually made of fiber glass, rock wool or cellulose, is blown into the attic or walls.’
- ‘You can compensate for this stacking effect and achieve the desired total R-value by adding about one extra inch of insulation if the old insulation is fiber glass, or about ½ inch if the old insulation is rock wool or cellulose.’