Effect of an Intermediate Material Layer on the Lateral Load-Slip Characteristics of Nailed Joints

The current understanding of the performance of nailed connections within light frame shear walls is limited to situations where sheathing is either in direct contact with framing, or with a small air gap in between the sheathing and framing. Current design standards in Canada conditionally allow the use of shear walls with a layer of gypsum wallboard between the sheathing and framing without compromising shear wall capacity. This type of wall assembly was experimentally tested on 132 tensile specimens replicating nailed connections in shear walls, incorporating intermediate material thicknesses ranging from 0 mm to 38.1 mm of gypsum wallboard or rigid insulation. Finite element and analytical models were created to simulate the performance of a nailed connection, and were validated by the experimental results. Results from this study suggest that adding gypsum or insulation will greatly decrease the capacity and stiffness of the connection.