Truss Bracket Shear Fastening for Studless Wall Systems
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Solution Overview
Problem
Traditional construction methods for securing roof trusses and floor joists to wall systems without a top plate nailing surface face challenges due to fasteners being in tension under uplift loads, reducing the structural integrity, especially under high wind conditions.
Innovation Solution
A truss bracket apparatus with a base plate, mounting tabs, and a vertical receiving plate is designed to attach roof trusses and floor joists to wall systems, where all fasteners are arranged in shear, enhancing the connection strength by using a top track with ribs and grooves to secure the bracket and track to the panels, ensuring that uplift loads are distributed through shear rather than tension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If toe nailing or L-clip arrangements are used to attach roof trusses to wall systems without top plate nailing surfaces, then the attachment can be made, but the fasteners are placed in tension under uplift loads, significantly reducing the connection strength
Solution Approach 1:
A metal bracket is introduced as an intermediary component between the roof truss and the wall system. The bracket includes a horizontal leg that attaches to the truss and a vertical leg that extends down into the wall cavity to engage with wall panels or blocking, thereby mediating the connection and eliminating the need for top plate nailing surfaces.
Solution Approach 2:
The fastening mechanism transitions from a two-dimensional surface attachment (nailing to top plate) to a three-dimensional volumetric engagement (vertical leg extending into wall cavity). This dimensional change allows the bracket to anchor within the wall assembly itself, providing tension resistance without requiring external nailing surfaces.
2Productivity
If traditional nailing methods are used, then attachment can be made, but uplift forces can dislodge fasteners by pulling nails from studs or top plate
Solution Approach 1:
The bracket is pre-assembled with the horizontal leg attached to the roof truss before installation. During installation, only the vertical leg needs to be positioned and fastened within the wall cavity, eliminating the need for现场 nailing operations and ensuring proper fastener placement without requiring top plate surfaces.
Solution Approach 2:
The bracket is divided into two functional segments: a horizontal leg for truss attachment and a vertical leg for wall engagement. This segmentation allows each leg to be optimized for its specific function and enables independent installation sequences that improve both speed and reliability.
3Device complexity
If wall systems use high in-plane end load bearing panels without studs or wood frame, then the structural system is simplified, but no nailing surface is available along the top of the wall for mounting clips or toe nailed roof trusses
Solution Approach 1:
The bracket design provides universal adaptability by accommodating multiple wall system configurations. The vertical leg can engage with various wall panel types, blocking arrangements, or structural elements within the wall cavity, making the solution applicable to different studless wall system designs while maintaining the same basic bracket form.
Data Source
AI summary
A truss bracket for mounting roof trusses and floor joists to wall systems absent traditional wood frame top plates utilizing in-plane end load bearing panels, resembling a chair, comprises a base plate with a vertical receiving plate extending upwards from the rear of the base plate for receiving a typical roof truss or floor joist and having downwardly extending mounting tabs along the left and right sides of the base plate suitable for being received by grooves in top track grooves of an in-plane end load bearing panel wall system or for attachment to the vertical sides of panels of a wall. The truss bracket provides high uplift load capacity by arranging all fasteners to the wall system and the truss or joint in shear when loaded.