What is OSB?
Oriented strand board (OSB) is an engineered wood panel made of compressed wood strands bonded with adhesive, used widely as sheathing and subfloor.
OSB is built from layers of wood strands oriented in alternating directions and pressed with resin into a strong, uniform panel. It's a common, economical alternative to plywood for wall and roof sheathing and for floor subfloor.
Like plywood, it's a structural panel rated for its use, and it needs to be kept dry or protected, since prolonged wetting can swell the edges.
More terms
Put it to work
Ask Donnie answers code questions cited to your jurisdiction and turns a plan into a deterministic estimate. Free to start.
Ask Donnie →General information to help you understand industry terms — not legal or professional advice. Confirm code and contract specifics with your local building department (AHJ) and a licensed professional.