Fire Separation Wall Hanger With Minimal Sheathing Cutout
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Solution Overview
Problem
Existing building codes require fire separation walls to maintain fire resistance while attaching structural components like trusses or joists, but attaching these components to wall framing disrupts the integrity of fire retardant sheathing, such as gypsum board, leading to a loss of fire resistance rating.
Innovation Solution
A hanger system with a channel-shaped portion and extension flanges that secure structural components to a wall while maintaining the integrity of fire retardant sheathing by extending through it, with back flanges engaging the wall to stabilize the hanger and prevent disruption of the sheathing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the entire cross section of the truss is cut out for attachment, then the truss can be securely attached to the wall, but the fire retardant sheathing is disrupted and the fire-resistant rating is compromised
Solution Approach 1:
The hanger is divided into distinct functional segments: a channel-shaped portion for receiving the truss, an extension portion for penetrating the sheathing, and a connection portion for attaching to the wall. This segmentation allows each part to perform its specific function while maintaining the overall integrity of the fire separation wall.
Solution Approach 2:
The hanger extracts only the minimal necessary portion of the sheathing (through the extension portion) rather than requiring a large cutout. This minimizes the disruption to the fire retardant sheathing while still providing adequate attachment capability.
2Reliability
If the fire retardant sheathing is maintained with minimal interruptions, then the fire-resistant rating is preserved, but the truss cannot be attached to the wall
Solution Approach 1:
The hanger acts as an intermediary device that bridges the truss and the wall without requiring direct attachment through large sheathing cutouts. It provides a mechanical connection path that bypasses the need for extensive sheathing removal.
Solution Approach 2:
The connection is achieved by extending the attachment path into the depth of the wall structure (through the extension portion penetrating the sheathing to engage the wall at a spaced location), rather than relying solely on surface-level attachment.
3Reliability
If extension flanges are used to extend through the sheathing, then the sheathing integrity is maintained, but the device complexity increases
Solution Approach 1:
The extension flanges serve multiple functions: they penetrate the sheathing, provide structural support, and enable attachment to the wall. This multi-functionality reduces the need for additional separate components.
Solution Approach 2:
The extension portion is integrated with the channel-shaped portion and connection portion as a unified hanger structure, combining multiple functional elements into a single device that can be installed as one unit.
Data Source
AI summary
A hanger for connecting a structural component to a wall that can have sheathing mounted thereon either before or after the hanger is connected to the wall. The hanger includes a channel-shaped portion configured to receive the structural component. An extension portion extends from the channel-shaped portion and is configured to extend through the sheathing to engage the wall at a first location. A connection portion is configured for attachment to the wall at a second location spaced from the first location.