A modular panel, the panel comprising a first member including a top surface and a bottom surface; an optional second member joined to the bottom surface of the first member; at least two reinforcing elements integrally disposed on the bottom of the first member; at least two elements integrally disposed on the bottom surface of the first member or on the second member for affixing and/or aligning the modular panel to at least two support members, each support member including a top surface; and a support flange integrally disposed about the periphery of the first member for engaging the top surface of the support member. The modular panel being constructed of a thermoplastic material or metal.