Metal decking underlayment material of interlocking pieces, namely, metal joists, metal connectors for decking and decking joists, and metal brackets, fitting and trim all for use in the construction and assembly of decking to provide horizontal surface for mounting decking material

extruded aluminum structural joist; interlocking tongue and groove underlayment panels of metal for receiving decking; prefabricated decking platforms of metal; flooring underlayment in the nature of a structural platform of metal for installing traditional decking and flooring materials