This specification covers the principal cellulosic fiber insulating board types, grades, and sizes. Insulating board covered by this specification consists of six types: Types I, II (Grades 1 and 2), III (Grades 1 and 2), IV (Grades 1 and 2), V, and VI. Cellulosic fiber insulating board shall be manufactured from refined or partially refined ligno-cellulosic (wood or cane) fibers, by felting or molding process, into homogeneous panels. The insulating board shall conform to the physical properties specified.

1.1 This specification covers the principal cellulosic fiber insulating board types, grades, and sizes. Requirements are specified for composition, construction, physical properties, tolerances, sampling procedures, and test methods.

1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.3 When the installation or use of thermal insulation materials, accessories, and systems may pose safety or health problems, the manufacturer shall provide the user appropriate current information regarding any known problems associated with the recommended use of the company's products and shall also recommend protective measures to be employed in their safe utilization. The user shall establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.