Tongue and Groove—helps to prevent both buckles and bows.
Staggered Seams—creates a more stable roof. Don't line up the sheathing sheets right above the other. Stagger them by starting every other row with a 4x4 sheet rather than a full 4x8 sheet.
Sheathing Thickness—will depend upon the type of sheathing used, however it is "Wise" to
Type of Material Used—Plywood, Wafer Board, or Particle Board. Through the knowledge and experience that I have gained, the best is tongue and groove plywood—especially if ever there is ever a leak. Other materials may weaken, or even disintegrate in a very short time when wet.
Moisture Prevention—Once the sheathing is installed, it is imperative that roofing felt be applied over it right away to prevent the sheathing from getting wet. When sheathing gets wet, it can warp, bow, and buckle.