Abstract: An aluminum deck structure, of the general type in which floor joists support and are secured to transverse decking members, is characterized by an assembly arrangement permitting rapid and inexpensive installation of decking members on floor joists without tools or fasteners, and allowing considerable thermal elongation and contraction of long decking members such as are used in platform tennis courts or other playing surfaces. In the deck structure, extruded aluminum decking members are formed with a floor plate and two depending vertical legs having bearing flanges and horizontally opposed latching members at their lower ends. Extruded aluminum floor joists have longitudinal ribs along their top supporting surfaces with pairs of notches in the ribs to receive the vertical legs of a decking member. The notches form opposed latching surfaces which meet and then snap into interlocking engagement with the latching members on the vertical legs as the legs descend into the notches.