When designing for shearwall overturning restraint, the designer is responsible for verifying that the building drift is within the acceptable code limitations. The designer should include project specific deformation limits for shearwall overturning restraint (Strong-Rod ATS) in the construction drawings and specifications including whether deformation is to include wood crushing under the bearing plate as well as any requirements set forth by local jurisdictions. Serviceability should also be considered.
Studs, posts and blocking details shall be specified by the designer and are not provided by Simpson Strong-Tie. Refer to strongtie.com/srs for compression member allowable capacities, design assumptions and general notes.
Anchorage solutions shall be specified by the designer. Foundation size and reinforcement shall be specified by the designer. Contact Simpson Strong-Tie to coordinate connecting components at the first level.
The Simpson Strong-Tie Strong-Rod Anchor Tiedown System for shearwall overturning restraint (Strong-Rod ATS) is designed to be installed floor-by-floor as the structure is built. Installation in this manner, with shearwalls, will provide lateral stability during construction.
Do not specify welding of products listed in this design guide unless this publication specifically identifies a product as acceptable for welding, or unless specific approval for welding is provided in writing by Simpson Strong-Tie. Cracked steel due to unapproved welding must be replaced.
Simpson Strong-Tie strongly recommends the following addition to construction drawings and specifications: “Simpson Strong-Tie connectors and tiedown components are specifically designed to meet the structural loads specified on the plans or provided by the designer. Before substituting an alternate rod system, confirm load capacity and system displacement (rod elongation and shrinkage compensation device displacement) are based on reliable published testing data and/or calculations and meet the design intent requirements specified by the designer. The designer should evaluate and give written approval for substitution prior to installation.
The allowable loads published in this guide are for use when utilizing the Allowable Stress Design methodology. A method for using Load and Resistance Factor Design (LRFD) for wood has been published in ANSI/AWC NDS-2018. If LRFD capacities are required, contact Simpson Strong-Tie.
Local and/or regional building codes may have additional requirements. Building codes often require special inspection of anchors installed in concrete and masonry. For compliance with these requirements, it is necessary to contact the local and/or regional building authority.
Steel bearing plates shall be sized for proper length, width and thickness based on steel bending capacity and wood bearing. Deflection of bearing compression (up to 0.04") must be included in overall shearwall deflection calculations where applicable by local and/or regional building authorities.
Available Strong-Rods, fully threaded rod sizes and material grades are listed at strongtie.com/srs.
When drilling thru-holes to accommodate the threaded rods, Simpson Strong-Tie strongly recommends that one continuous hole be drilled upon completion of the entire floor system at each level. Misalignment may occur when drilling is staged over several different construction steps, which leads to binding and bending of the threaded rod. See installation animations for further description at strongtie.com/srs.