Uplift Capacity of Light-Frame Rafter to Top Plates Connections Applied with Elastomeric Construction Adhesives

Abstract

The effects of the application of elastomeric construction adhesives on the wind uplift resistance of light-frame wood connections were investigated and are presented in this paper. Previous research has revealed that proper roof-to-wall connections play a critical role in mitigating structural damage during severe winds by providing a continuous load transfer path from the roof down to the foundation. Monotonic uplift tests of 30 rafter-to-top-plates connections of six configurations were conducted. Two specimen groups, standard ring shank nails alone and strengthened with hurricane ties, were constructed with and without elastomeric adhesive application, and their wind uplift resistances were compared to explore the effectiveness of the two adhesives (i.e., polyurethane and polyether) when applied to the roof connections. Experimental results show that the addition of adhesives allowed both groups to resist higher uplift loads (approximately 200%–460%) and dissipate considerably more energy (approximately 200%–750%). Replacing hurricane ties with the adhesives approximately doubles the uplift capacity but reduces the energy dissipation by nearly half owing to reduced deformation capacity. Failure modes were also examined to provide reasonable explanations for the observed performance of the connections.