Abstract: A modular deck construction characterized by having one or more prefabricated floor panels with prefabricated stair parts, i.e., treads and side runners, together with prefabricated banisters and side railing members. The deck frame and other parts are pre-drilled as necessary to provide a fail-safe arrangement for mounting the stairs, banisters, and side rails with the floor panel such that the stair may be positioned on either side or either end of the floor deck. The modular system facilitates assembling a deck of any number of the prefabricated floor panels. The invention also includes connecting means for joining interior corners of adjacent floor panels and supporting them in an elevated position above ground level.