FIBREBOARD

also spelled Fiberboard, construction material made of low-quality wood fibres by pulping, forming into sheets, pressing, and mixing with binders or other additives to impart water resistance, strength, and fire resistance. The sheets are felted or matted and bonded together by either a dry or a wet process. Denser sheets of fibreboard are used for paneling or exterior siding, the less dense for insulation. Fibreboard may be decorated with patterns or overlays.