SDWF Structural Wood Screw for Floor-to-Floor Connections

The Simpson Strong-Tie® SDWF structural wood screw is designed to simplify the floor-to-floor connection while providing superior performance over the life of the structure. The unique design of the SDWF allows it to attach the top and bottom walls together from the top, spanning the floor system and providing an easy-to-install connection within the continuous load path of the structure.

A key to the long-term performance of the SDWF lies in the innovative TUW take-up washer that is installed between the screw and the bottom plate of the top floor. As the structure settles due to shrinkage and construction loading, the threaded portion under the head of the screw ratchets up through the tabs of the TUW (which is secured in place). 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.

Features:

Faster to install than other methods – drive the screw and the connection is made
Shrinkage compensation ensures a tight connection even after initial shrinkage and settlement occur
Fastening can be done before or after exterior sheathing is applied for added flexibility
Installs from inside the structure, eliminating exterior work on the upper stories and enhancing job safety
The TUW take-up washer installs with (4) #9x2 1/2" Strong-Drive® SD structural-connector screws (provided)

Material: Carbon steel

Finish: SDWF—E-Coat™; TUW—Galvanized

Installation:

See General Notes.
To choose the appropriate SDWF length, add 6" to the joist size.
SDWF installs best with low-speed, high torque (200 in-lbs minimum) drill with a 5/16" hex-head driver.
See details for minimum edge/end fastener distances.
To install:
- Drive the SDWF into the upper-wall bottom plate vertically (90°± 2°), until the head is a minimum of 2" above the plate.
- Slide the TUW over the SDWF head and center.
- Continue driving the SDWF until the washer head contacts the TUW tabs and bends them until they engage the shank of the SDWF directly under the head.
- Secure the TUW to the upper-wall bottom plate with #9x2 1/2" SD screws (provided)

Table based on testing conducted in accordance with ICC-ES AC233. Design values presented are based on average ultimate divided by 5.
Allowable loads are shown at a wood load duration factor of C_D = 1.0. Loads may be increased for load duration up to C_D = 1.6.

Spacing listed based on limits 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. Screw allowable withdrawal as described in footnote 2.
Spacing listed considers reference allowable withdrawal load with C_D = 1.6 and minimum 3" penetration into lower wall double top plates.
Minimum end distance to any top plate splice is 4" for all SDWF fasteners. Minimum edge distance is 1".
One SDWF screw must be installed between 4"-12" from any upper-wall bottom-plate splice.
Stud-to-plate connection to be designed and detailed by designer of record to complete continuous load path. Consider the SDWC screw for stud-to-plate connection..

Download the Simpson Strong-Tie® AutoCAD® Menu, which allows you to insert Ortho views directly into your AutoCAD drawing.

	ORTHOGRAPHIC	PERSPECTIVE
SDWF	SDWF Installation: DWG \| DXF SDWF front view: DWG \| DXF SDWF left view: DWG \| DXF	SDWF: DWG \| DXF SDWF Installation: DWG \| DXF
SDWF2716-TUW	None for this model	None for this model
SDWF2720-TUW	None for this model	None for this model
SDWF2724-TUW	None for this model	None for this model
TUW38	TUW38 back view: DWG \| DXF TUW38 front view: DWG \| DXF TUW38 left view: DWG \| DXF	TUW38: DWG \| DXF

					Legacy Reports
	IAPMO ES ER	ICC-ES ESR	CITY OF LOS ANGELES	STATE OF FLORIDA	ICC-ES NER	ICC-ES ER	ICC-ES ES
SDWF	No code listing. Please contact us for test data.
SDWF2716-TUW	No code listing. Please contact us for test data.
SDWF2720-TUW	No code listing. Please contact us for test data.
SDWF2724-TUW	No code listing. Please contact us for test data.