High Heel Roof-to-Wall Connection Testing

This study is Phase III of a test program that responds to the new requirements for roof-to-wall connections in 2012 International Residential Code (IRC) and expands upon the previous phases that evaluated innovative roof-to-wall connection systems.

The new IRC provisions specify complex details for attachment of rafters and trusses to the supporting walls (ICC 2012). These new requirements, which apply to high-heel energy trusses even in the low-wind areas, are labor intensive and add cost to construction of light-frame wood buildings. A previous testing project (NAHBRC 2011) conducted to evaluate optimized structural roof-to-wall attachment solutions demonstrated the effectiveness of wood structural panels in restraining high heel (i.e., energy) trusses against rotation. Further testing conducted by the NAHBRC (NAHBRC 2012) confirmed the ability of OSB wall sheathing panels extended over the roof heel to resist combined uplift and shear forces without additional roof-to-wall hardware.

Phase III builds upon this previous testing by evaluating the performance of the extended wall structural panel connection in resisting combined uplift and shear forces at the roof-to-wall interface with a focus on a truss heel height of 24 inches to address the expected increases in the depth of attic insulation used in Climate Zones 5 and higher.

The results of this study are expected to further expand prescriptive construction solutions optimized for performance from the structural, energy, and constructability standpoint.

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