1. Scope1.1General This Standard provides minimum requirements for insulating fibreboard manufactured from wood or other vegetable fibre. The boards may be surface-coated or uncoated and either single-ply or multiple-ply.1.2Types This Standard covers the following types of insulating fibreboards: (a) Type I - roof board; (b) Type II - sheathing; (c) Type III - interior boards: (i),building board (sound-deadening); (ii) ceiling tile; (iii) lay-in panel. (d)Type IV - backerboard.