Abstract: Mechanically fastened appended tabs invisibly secure common edge-abutting wallboard panels to common wood or metal framing members. The fastener appendants are spaced apart tabs extending from the back of and exposed beyond the vertical edges of the wallboard panels so as to be conveniently screw fastened. When screw fastened to common wall framing members, the appended tabs secure the wallboard panels slightly off the framing member front surface to permit offset appendant tabs of abutting wallboard panels to slide between the fastened wallboard panels and the framing members and be engaged by the fastened wallboard panels in a tongue and groove relationship.

Abstract: An intersection cap for covering the ends of a plurality of pieces of grid celing trim mounted on grid ceiling supports where such supports intersect, usually at right angles, includes a base member, usually cruciform in shape, but sometimes readily convertible to T-shape, for covering the horizontal surfaces of the trim and of any exposed support, wall members extending upwardly from the base member, for covering the sides of the trim and of any exposed support and opposed retainers located at tapered portions of the walls at the ends thereof and beyond the base member which readily, yet firmly, snap fasten onto the trim. Also described is the injection molding of such intersection caps in which the mold parts are moved together in simple linear relative motion to obviate the employment of complex mold part motions to form suitable retainers integral with the walls of the intersection cap.

Abstract: A decorative trim strip and a suspended ceiling construction employing the trim strip with structural T- and L-beams having laterally extending portions or portion, wherein such trim strip is a resilient longitudinal "J" channel section having a lengthwise opening communicating with the interior thereof through which a laterally extending portion of a structural beam can be inserted internally to engage and maintain the decorative trim strip.