Evaluation of Nailed Roof-to-Wall Connections for Resistance to Uplift
In light-frame wood construction, nails have historically been the primary method for connecting roof members to walls. The connection, known as a toe-nail or a slant-nail, is fabricated by installing nails at an angle through the side of a roof framing members and into the wall’s top plate. Model building codes allowed the use of toe-nails under conventional construction provisions in areas not prone to hurricanes. Recently, proposals to modify the conventional construction provisions to substantially reduce the applicability of toe-nailed connections have been discussed at various code development forums. This study is intended to provide the basis for establishing appropriate scoping limits for toe-nailed roof-to-wall connections in applications under the International Residential Code (IRC).
This testing program is designed to measure the uplift capacity of conventional light-frame roof connections. Testing is conducted on roof systems of rafters, rafters with ceiling joists, and trusses attached to the wall top plate using toe-nailed joints. The purpose of this study is to better understand how the roof-to-top plate connection performs as part of the roof system. Testing conducted by others (see Background) suggests that significant system effects are present when connections are tested as part of a roof assembly as compared to values for individual nails or individual connections predicted by engineering analysis or evaluated by testing. The system response provides potential for load sharing between individual connections, particularly connections with variability in resistance.
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