Oriented strand board, also known as OSB, waferboard, Sterling board or Exterior board (UK) and SmartPly (UK & Ireland), is an engineered wood product formed by layering strands (flakes) of wood in specific orientations. In appearance, it may have a rough and variegated surface with the individual strips (around 2.5 by 15 cm (approx. 1 in by 6 in) each) lying unevenly across each other. Show More