Capacity of Oriented Strand Board Shear Walls with Overdriven Sheathing Nails

Abstract

Eight shear wall specimens sheathed with 11 mm structural oriented strand board panels were assembled with overdriven sheathing nails and tested using a pseudo-dynamic procedure. Specimens used 38×89 mm Douglas Fir-Larch framing members and 8d cooler, gun-driven sheathing nails. Four overdriven nail depths were considered: flush, 1.6, 3.2, and 4.8 mm. Nails were spaced at 76 mm on center along the edges and 305 mm on center along intermediate supports. Edge nailing distance was 9.5 mm. Two specimens were constructed for each aforementioned overdriven depth. To determine a lower bound on capacity, 100% of the sheathing nails in a specimen were driven to the specified depth. Results from this study indicate that any level of sheathing-nail overdrive will reduce the capacity of a shear wall. Compared to specimens with flush-driven nails, specimens with nails overdriven 1.6 mm suffered 5% loss in strength and gained 1% in displacement capacity. Specimens with nails overdriven 3.2 mm had strength and displacement capacity reduced by 12 and 22%, respectively. Specimens with nails overdriven 4.8 mm fared poorly; strength was reduced 24%, and displacement capacity was reduced 56%.