This document defines wood-based panels for use in construction and specifies the relevant characteristics and the appropriate test methods to determine these characteristics for wood-based panels, unfaced, overlaid, veneered or coated: for internal use as structural components in dry conditions1); for internal (or protected external) use as structural components in humid conditions2); for external use as structural components3); for internal use as non-structural components in dry conditions1); for internal (or protected external) uses as non structural components in humid conditions2); for external use as non-structural components3); for use as structural floor decking on joists in dry1) or humid2) or external3) conditions; for use as structural roof decking on joists in dry1) or humid2) or external3) conditions; for use as structural wall sheathing on studs in dry1) or humid2) or external3) conditions. It provides for the evaluation of conformity and the requirements for marking these products. This document covers wood-based panels in the form of solid wood panels, LVL 4 ), plywood, OSB, particleboards (chipboards) either resin- or cement-bonded, wet process fibreboards (hardboards, medium boards, softboards) and dry process fibreboards (MDF) for use in construction. They may contain chemical agents to improve their reaction to fire and their resistance to biological attack, e. g. by fungi and insects. This document is not intended to be applicable to wood-based panels for use in non-constructional applications.