Buckling of Conventionally Sheathed Stud Walls

Sheathing materials such as plywood, oriented strand board (OSB), drywall, and fiberboard are commonly attached to one or both sides of load-bearing stud walls in residential and commercial construction. There is no consensus among structural engineering professionals as to which of these sheathing materials provide protection against weak-axis buckling of the loadbearing wood studs. Plywood is generally accepted as providing the necessary bracing, but building codes do not specifically state which of the other sheathing materials are acceptable for bracing studs against compression buckling. This study involves testing of 2.44 m (8 ft) tall by 1.22 m (4 ft) wide stud wall specimens sheathed with OSB both sides, OSB one side, drywall one side, drywall both sides, Thermo-Ply one side, fiberboard one side, and no sheathing. The allowable axial load according to the wood specification for a 1.22 m (4 ft) long wall specimen with studs braced in the weak direction is 42.5 kN (9,546 lb). Each of the sheathed specimens failed at more than 2.9 times the allowable load; i.e., each sheathing material provided a factor of safety of at least 2.9 against strong-axis buckling under compression load. Therefore, each of the materials, when properly attached, was capable of resisting weak-axis stud buckling. Specimens with drywall fastened to one or both sides had a higher ultimate load than specimens with oriented strand board fastened to one side.