Simpson Strong Tie SDWC15600-KT Strong Drive Structural Wood Screw
*For further description please see Simpson Strong-Tie Fastening Systems Catalog.
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SDWC Strong-DriveŽ Structural Wood Screw for Truss and Rafter Connections
The Strong-DriveŽ SDWC provides a time-saving and reliable option to fastening trusses and rafters to wall top plates. The SDWC offers fully tested loads in accordance with ICC-ES AC233 (screw) and ICC-ES AC13 (roof-to-wall assembly), and installs easily and effectively without pre-drilling.
The SDWC is sold in a kit (SDWC15600-KT) that includes:
(50) 6" Strong-Drive SDWC screws
Matched tolerance, T-30, 6-lobe driver bit
Metal installation guide tool
Fully-threaded shank engages the entire length of the fastener, providing a secure connection between the roof and wall framing members
Cap-style head countersinks fully into the double top plate to avoid interference with drywall or finish trades
Wide installation-angle range makes it easier to install the SDWC correctly
Can be installed from inside the structure, eliminating exterior work on the upper stories and enhancing job safety
Fastening can be performed before or after exterior sheathing is applied for added flexibility
Metal installation guide tool (included) to help ensure proper installation
Matched-tolerance driver bit (included) engages fastener head securely to allow one-handed driving (replacement bit part no. BIT30T-R1)
Type-17 point for faster starts and easier driving
6-lobe drive reduces cam out, enabling easier driving
Material: Carbon steel
Finish: Clear zinc
See SDWC flier (PDF).
Loads have been increased 60% for wind or earthquake loading with no further increases allowed; reduce where other loads govern.
Allowable loads are for an SDWC installed per the 'Recommended' or 'Optional' installation instructions. The SDWC is to be installed through a double 2x top plate into a minimum 2x4 truss or rafter.
SDWC screws may be used in 2- or 3-ply rafters or trusses.
The allowable uplift load for each screw shall be multiplied by 0.90, but may be limited by the capacity of the plate or the connection between the top plate to the framing below. SDWC screws in multi-ply assemblies must be spaced a minimum of 1 1/2" o.c.
Screws are shown installed on the interior side of the wall. Installations on the exterior side of the wall are acceptable when the rafter or truss overhangs the top plates a minimum of 3 1/2".
For Uplift Continuous Load Path, top plate to stud connectors such as the H2.5A, TSP or MTS12 must be located on the same side of the wall as the screw.
When the screw is loaded simultaneously in more than one direction, the allowable load must be evaluated using the following unity equation:
(Design Uplift ÷ Allowable Uplift) + (Design F1 ÷ Allowable F1) + (Design F2 ÷ Allowable F2) ≤ 1.0.
Table loads do not apply to trusses with end-grain bearing.
Top plate, stud and top plate splice fastened per applicable Building Code.
Continuous Load Path Considerations
Building codes require structures to be designed to create a continuous load path. Forces must be transferred from their point of origin to the building elements that are designed to resist them. When uplift forces act on a roof, the roof must be tied down to the wall below it; and if the uplift forces are large enough, the wall must be tied down to the foundation or wall below.
Like many common hurricane ties, the Strong-DriveŽ SDWC screw fastens the rafter or truss directly to the top plate of the wall below. The wall top plate alone does not offer sufficient resistance to roof uplift forces, and therefore must be tied to the studs or framing below. This connection may be made with structural sheathing designed for uplift or a metal connector installed on the same side of the wall as the SDWC; however, the fasteners of the sheathing or connector must not interfere with the SDWC. The Simpson Strong-TieŽ H2.5A, TSP, and MTS12 are ideal metal connectors for this application.