Hook and Strip Roofing Fastener with Lateral Wings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Newer slate tile roofing systems with reduced tile overlap and 'hook and strip' fasteners fail to securely hold tiles in high winds, leading to tile displacement due to wind pressure.
Innovation Solution
A hook and strip roofing system with integral laterally-extending wings and a short shank hook design that secures the fastener to the roof, reducing bending moments and preventing tile release during high winds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional three-layer overlapping slate tile system is used, then wind resistance is improved, but tile weight and material usage increase
Solution Approach 1:
The fastening system is segmented into multiple functional components: anchor portion for roof attachment, shank portion for penetration, and hook portion for tile engagement. This segmentation allows each component to be optimized for its specific function while reducing overall material usage compared to conventional three-layer overlapping systems.
Solution Approach 2:
The invention transitions from a vertical overlapping arrangement (three-layer system) to a horizontal fastening arrangement using hook and strip fasteners. This dimensional change allows for reduced tile weight while maintaining wind resistance through a different mechanical approach - anchoring fasteners to the roof and using hooks to secure tiles laterally.
2Ease of operation
If hook and strip fasteners with long shank are used, then ease of installation is improved, but wind resistance deteriorates due to increased bending moments
Solution Approach 1:
The shank length parameter is changed from long to short, fundamentally altering the bending moment characteristics. The short shank reduces the lever arm for wind-induced bending, preventing the hook from opening up under wind load while still allowing easy installation through the tile edge.
Solution Approach 2:
Instead of using a long shank that cantilevers outward and creates large bending moments, the invention inverts the approach by using a short shank that minimizes exposure to wind forces. The anchor portion is positioned below the tiles to provide upward resistance, effectively inverting the traditional hook and strip fastener configuration.
3Quantity of substance
If reduced overlap tile system is used, then material cost and weight are reduced, but wind resistance deteriorates due to increased lifting forces
Solution Approach 1:
The anchor portion of the fastener is positioned below the tiles and extends downward to engage with the roof deck. This creates a counterbalancing force that resists upward lifting forces generated by wind pressure on the reduced overlap tile system, effectively counteracting the reduced weight advantage.
Solution Approach 2:
The fastener is pre-configured with the anchor portion positioned below the tiles and the hook portion extending upward to engage the tile edge. This preliminary positioning ensures that when wind applies lifting forces, the fastener is already in the optimal configuration to resist these forces, preventing tile displacement without requiring additional material.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively secures slate and ceramic tiles under winds up to 110 miles per hour by minimizing bending forces on the fasteners, preventing tile loss and ensuring robust attachment.
Implementation Method 1
The wings secure the free or bottom end of the fastener and the hook closely to the underlying roof. With a short shank of the hook pressed against a weatherproofing sheet underlying the tile, and the wings pressed against the weatherproofing sheet by the weight of two adjacent tiles, the hook and free end of the fastener from which the hook extends are securely held in place.
Implementation Method 2
This is contrasted with a relatively long cantilevered shank and hook on conventional hook and strip fasteners which are subject to large bending moments from high winds. Once the free end portion and the hook portion of these conventional fasteners begin to bend upwardly as the tiles pivot and lift the fasteners upwardly about their attachment points on a mounting strip, the fasteners quickly lift up from the roof.
Data Source
AI summary
An integral strip and fastener installation system is provided for light weight slate and tile roofing systems installed with a single overlap between each row or course of tile. A specialized fastener hook is formed with one or more lateral projections or wings installed underneath one or more slate tiles to anchor the fastener to the roof at least in part by the weight of the overlying tiles. This anchoring supports and reinforces the open mouth of the hook against deflection from high winds and thereby enables the hook to hold a tile securely under high wind loads.