Floor Truss Rimboard: Framing member installed on edge of the exterior perimeter, usually tying the ends of floor trusses together. Also called rim joist, ribbon, or band board. Continuous ribbons provide stability for installed trusses, and also provide solid nailing surface for the edge nailing of floor sheathing. This eliminates the need for larger “band-board” solutions required by dimensional lumber and other engineered wood products.