1.1 This specification covers the composition and physical properties of insulating boards composed of wood fiber insulation board laminated to rigid cellular polystyrene insulation board, flat or tapered, used principally above structural roof decks for thermal insulation as well as a base for roofing in building construction.

1.2 The values stated inch-pound units are to be regarded as the standard. The values in parentheses are provided for information only.

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.