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Strong-Drive® SDWF FLOOR-TO-FLOOR Screw 

Strong-Drive® SDWF FLOOR-TO-FLOOR Screw

The Strong-Drive SDWF Floor-to-Floor screw is designed to simplify the wind-uplift restraint connection while providing superior performance over the life of the structure. The unique design of the SDWF enables it to attach upper and lower walls together from the top, spanning the floor system and providing an easy-to-install connection within the continuous uplift load path of the structure.

The innovative Take-Up Washer (TUW) plays a key role in the long-term performance of the SDWF when installed between the screw head and the sole plate of the upper floor. As the structure settles because of shrinkage and construction loading, the threaded portion under the head of the screw ratchets up through the tabs of the TUW, which is fastened with Simpson Strong-Tie Strong-Drive SD screws. The interlock between the tabs of the take-up washer and the threads under the head of the SDWF prevent the screw from sliding back under load, providing a simple yet reliable means of shrinkage compensation up to 3/4" per story.

Key Features

  • Faster to install than other floor-to-floor connection methods — drive the screw, install the take-up washer and the connection is made from plate-to-plate
  • Shrinkage compensation ensures a tight connection even after initial shrinkage and settlement occur
  • Installs from inside the structure, eliminating exterior work on upper stories and enhancing job safety
  • Fastening can be done before or after exterior sheathing is applied for added flexibility
  • One screw length can be used for multiple floor depths (refer to chart to select appropriate screw size), reducing the need for many screw lengths

Applications

  • Wind-uplift restraint connections

Product Includes

Kit includes all required installation hardware:

  • (25) Strong-Drive SDWF Floor-to-Floor screws
  • (25) TUW take-up washers (washer is galvanized 10 ga. steel)
  • (100) Strong-Drive SD Connector screws (#9)
  • 5/16" hex driver bit (replacement driver bit — BITHEXR516-134)
  • Screw depth guide to ensure proper SDWF engagement with TUW

Related Literature

Product Information Table

Model No. Length (in.) Drive Type Head Diameter (in.) Head Type Thread Length Thread Type Shank Diameter (in.) Point Type Coating/Material Packaging Quantity UPC
SDWF2716-TUW 16 5/16 in. Hex 0.73 Hex Washer Head 5 Variable Thread Design 0.270 Type-17 Point E-Coat™ Electrocoating 25 707392478805
SDWF2720-TUW 20 5/16 in. Hex 0.73 Hex Washer Head 5 Variable Thread Design 0.270 Type-17 Point E-Coat™ Electrocoating 25 707392885405
SDWF2724-TUW 24 5/16 in. Hex 0.73 Hex Washer Head 5 Variable Thread Design 0.270 Type-17 Point E-Coat™ Electrocoating 25 707392845904
SDWF2726-TUW 26 5/16 in. Hex 0.73 Hex Washer Head 5 Variable Thread Design 0.270 Type-17 Point E-Coat™ Electrocoating 25 707392448709

Load Tables

Product Information and Withdrawal Loads

  1. Allowable loads are for CD=1.0 and may be increased for load duration up to CD = 1.6.
  2. Joist depth listed based on the 3/4" subfloor and 3" of thread penetration into double top plates.

SDWF-TUW Floor-to-Floor Screw — On Center Spacing for Uniform Uplift Loads

  1. Spacing listed based on lesser of: single bottom plate bending allowable load, single bottom plate deflection limited to spacing/240 and 1/4" max, screw allowable withdrawal load, and take-up washer allowable load.
  2. Withdrawal load is based on a CD = 1.6 and minimum 3" penetration into lower wall double top plates.
  3. Stud-to-plate connections are required to complete the load path. These connections shall not exceed the lesser of 48" o.c. or SDWF spacing.
  4. Spacing values listed for SP lumber consider new base values adopted by AWC on June 1, 2012.

Concentrated Uplift Loads

  1. Allowable loads listed include a wood load duration factor of CD = 1.6 for wind or earthquake loading with no further increase allowed; reduce when other loads govern.
  2. Single and double SDWF-TUW applications listed are for concentrated load uplift restraint conditions (i.e. end of header, at girders, or at the end of shearwalls).

See additional Load Tables, Technical Data and Installation Instructions for the Strong-Drive® SDWF Floor-to-Floor screw

Drawings

Part Orthographic Perspective
SDWF
Wind Uplift Restraining Strong-Drive Screw Fastening Systems
DWGDXF
SDWF Installation
DWGDXF
SDWF front view
DWG DXF
SDWF left view
DWG DXF
High Wind-Resistant Construction D46: Stud to Stud
DWG DXF
SDWF
DWG DXF
SDWF Installation
DWG DXF
SDWF2716
Wind Uplift Restraining Strong-Drive Screw Fastening Systems
DWGDXF
SDWF2716 bottom view
DWG DXF
SDWF2716 front view
DWG DXF
SDWF2716 left view
DWG DXF
SDWF2716 right view
DWG DXF
SDWF2716 top view
DWG DXF
SDWF2716
DWG DXF
SDWF2720
Wind Uplift Restraining Strong-Drive Screw Fastening Systems
DWGDXF
SDWF2720 bottom view
DWG DXF
SDWF2720 front view
DWG DXF
SDWF2720 left view
DWG DXF
SDWF2720 right view
DWG DXF
SDWF2720 top view
DWG DXF
SDWF2720
DWG DXF
SDWF2724
Wind Uplift Restraining Strong-Drive Screw Fastening Systems
DWGDXF
SDWF2724 bottom view
DWG DXF
SDWF2724 front view
DWG DXF
SDWF2724 left view
DWG DXF
SDWF2724 right view
DWG DXF
SDWF2724 top view
DWG DXF
SDWF2724
DWG DXF
SDWF2726
SDWF2726 bottom view
DWG DXF
SDWF2726 front view
DWG DXF
SDWF2726 left view
DWG DXF
SDWF2726 right view
DWG DXF
SDWF2726 top view
DWG DXF
SDWF2726
DWG DXF
TUW38
Wind Uplift Restraining Strong-Drive Screw Fastening Systems
DWGDXF
TUW38 back view
DWG DXF
TUW38 front view
DWG DXF
TUW38 left view
DWG DXF
TUW38
DWG DXF