Top-Plate-to-Stud Rotation Restraint
The roof-structure-to-top-plate connection induces eccentric loads to the top plate. This will require a top-plate-to-stud connection to continue the load path and prevent torsional rotation of the top plates. Simpson Strong-Tie offers a variety of product options to resist the rotational forces from the roof structure.
| AC391 Criteria Section | AC391 Requirement |
|---|---|
| 3.2.2.3 | Top-plate torsion (rotation) must be prevented due to offsets between the point of load application, such as hurricane ties at the sides of the top plates and load resistance (rods at the center of the top plate for example). This can be accomplished by providing a positive connection from the top plate to stud on the same side of the wall as the roof framing to wall connection. |
When connection hardware between the roof framing members and the wall top plate induces eccentric loading about the centerline of the top plate, Simpson Strong-Tie top-plate-to-stud connectors are the optimum installation solution to prevent top-plate rotation as shown in illustration below. The top-plate-to-stud connectors must be installed on the same side of the top plate as the roof-to-wall connectors. Connector models must be selected and installed in a manner that does not induce significant tension stresses perpendicular to the grain of the wood top-plate members.
Required Top-Plate Rotation Restraint Connection Force1
For SI:1 inch = 25.4mm
- The top-plate-to-stud connection used to restrain top plate rotation must be installed on the same side of the wall as the roof-to-top-plate connection.
For hurricane tie components that can connect top plates to studs to resist rotation, refer to the High Wind Guide (F‑C‑HWG) or the Wood Construction Connectors catalog.
