OSB sheathing is a special type of board that is well-engineered being composed of strands of compressed wood which are layered and unionized together using a resin. It differs from commonly used plywood in many aspects. For example, it does not have voids or knots, or gaps and laps. A lot of ... May 15, 2016 · Now we could have just throw a few new sheets of drywall up but a few months ago. I tore down all the drywall on his garage walls and installed OSB instead . Cody has been really happy with it so since we already have to work on the ceiling, I talked him into replacing all the old sheetrock with OSB here as well.