Abstract: A board for use in constructing exterior floors has a rounded or curved convex top surface to shed water, and a complementally shaped rounded or curved concave bottom surface for nesting engagement with the top surface of an adjacent board so that a plurality of the boards may be stacked in stable relationship. The radius of curvature of the rounded top surface is such that a floor formed by a plurality of the boards placed side-by-side provides a comfortable surface on which to stand and walk. In a modification, the bottom surface has a plurality of stress-relief channels formed therein to prevent cupping or warping of the board.

Abstract: A flooring system in which flooring boards are held to an underlying support structure by use of clips that eliminate the need for fasteners extended through the flooring boards. In a preferred form of the invention, the clips have a barbed projection that is adapted to extend into a groove formed in the bottom of the flooring board to grip the board and hold it to the support structure. With this form of the invention flooring boards may be secured to a support structure simply by fastening the clips to the support structure and then pressing the boards into place on the clips. In another form of the invention, the clip is slidably attached to the support structure so that it can slide along the support structure, thereby enabling the boards to be moved toward one another after assembly to the support structure for reducing any gaps or spaces between adjacent boards.