OSB Board (Oriented Strand Board) OSB3 Square Edge 2440 X 1220 X 18mm Strong, stable and more sustainable, oriented strand board (OSB) is replacing plywood - especially for timber framed houses and in the packaging industry. OSB is used instead of standard silica or plaster-based construction materials. To produce oriented strand board, timber is sliced into long chips called strands. These are laid in three or four perpendicular layers and bonded using ECO resin. The result is a strong board that resists moisture, giving it a high load capacity. Flexible yet strong, OSB board is used for many applications.