Abstract: A construction panel having first and second edge portions arranged for interconnection with respective second and first edge portions of similar panels, the first and second edge portions being configured for mating engagement at at least two locations, the first edge portion including a generally flat portion arranged to permit attachment of the edge portion to an external support by a fastener extending through the flat portion, the mating engagement of the first and second edge portions being such that the generally flat portions and the fastener are covered by the second edge portion.