Constructional panels

A panel construction comprising:

• a plurality of constructional panels, each having first and second edge portions arranged for interconnection with respective second and first edge portions of similar panels, said first and second edge portions being configured for mating engagement at at least two locations, said first edge portion including a generally flat portion arranged to permit attachment of the edge portion to an external support;
• and
• a plurality of fasteners extending through said flat portions of said plurality of constructional panels and mounting them onto an external support,
• adjacent panels being in mating engagement being such that said generally flat portion and said fastener are covered by said second edge portion, and wherein
• each panel comprises first and second spaced apart portions defining respective first and second outer surfaces lying in respective first and second planes, said first edge portion having a third outer surface substantially coplanar with said first surface and said second edge portion having a fourth outer surface substantially coplanar with said second outer surface, and
• said first edge portion defines a first protrusion defining said third outer surface, said first protrusion also defining first and second locking portions, and said second edge portion defines a second protrusion defining said fourth outer surface and a pair of spaced apart teeth mounted onto said second protrusion so as to extend transversely to said second plane and towards said first plane and so as to be lockably engageable with said first and second locking portions, thereby to define said at least two locations.