Subflooring Direction of Installation

(1)  Plywood subflooring shall be installed with the surface grain at right angles to the joists and with joints parallel to floor joists staggered.

 (2)  OSB subflooring conforming to CSA O325, “Construction Sheathing”, or to O-1 and O-2 grades in CSA O437.0, “OSB and Waferboard”, and waferboard subflooring conforming to R-1 grade in CSA O437.0 shall be installed so that the direction of face orientation is at right angles to the joists and the joints parallel to the floor joists are staggered.

Article 9.23.14.4. Ontario Regulation 332/12 Building Code,   Information published by oncodes.ca for educational purposes only.