Weep Hole Insert with Heat-Resistant Grate

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Solution Overview

Problem

Existing weep hole devices in masonry walls are prone to failure during high temperatures, such as bushfires, allowing firebrands and sparks to enter the wall cavity, and lack easy access for inspection or maintenance, while also being susceptible to vermin and insect infestations and mortar clogging.

Innovation Solution

A weep hole insert with a hollow body and a heat-resistant, self-extinguishing polymer grate that maintains structural integrity during high heat exposure, featuring a stainless steel screen with small cells to prevent insects and firebrands, and a hinged design for easy inspection and access, along with a mortar guard to prevent clogging during rendering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a traditional weep hole opening is used in masonry walls, then ventilation and drainage are provided, but the opening allows firebrands and sparks to penetrate the building, and provides entry for vermin and insects

Engineering Contradiction:
Improvefirebrand penetration preventionVSAvoidstructural integrity during high heat
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The device segments the weep hole function into distinct components: a screen component with small apertures for firebrand filtration, a grate component for vermin and insect prevention, and a body component for structural support. Each component addresses specific harmful factors while maintaining overall system reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The device employs composite material construction combining metal screens for fire resistance, polymer grates with heat-resistant properties, and mortar-resistant materials. This composite approach ensures the structure maintains integrity during high heat events while providing multiple protective functions.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If a screen and grate are installed in the weep hole device, then firebrands and vermin are prevented from entering, but the device becomes complex and difficult to install

Engineering Contradiction:
Improvevermin and insect entry preventionVSAvoidinstallation complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The screen, grate, and body are merged into a single integrated assembly that functions as one unit. This merging eliminates the need for separate installation steps for each component, reducing installation complexity while maintaining all protective functions including vermin and insect prevention.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated device performs multiple functions simultaneously: firebrand screening, vermin prevention, insect blocking, and ventilation. This multi-functionality is achieved through a single universal component assembly that replaces multiple separate devices, simplifying installation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If the weep hole device is made from heat-resistant material, then structural integrity is maintained during bushfires, but the material may be expensive or difficult to manufacture

Engineering Contradiction:
Improveheat resistanceVSAvoidmanufacturing ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Heat-resistant properties are applied locally to specific components (such as the screen and grate areas most exposed to fire) rather than requiring the entire device to be made from expensive heat-resistant materials. This local quality approach maintains reliability during bushfires while improving ease of manufacture.

Inventive Principle:
Principle #3Local quality

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 solution effectively prevents firebrand penetration, retains structural integrity during high heat events, allows for easy inspection and maintenance, and prevents vermin and insect entry, while ensuring easy installation and adjustment within weep hole openings.

Implementation Method 1

a screen extending across the conduit near the first open end and adapted to prevent fire brands and sparks from passing through the body

Methodology Applied
Scientific EffectPhysical barrier blocking:

Implementation Method 2

the locating member is formed from a material that substantially retains its spatial integrity when exposed to a predetermined heat flux profile and continues thereafter to locate the screen

Methodology Applied
Scientific EffectThermal stability:

Implementation Method 3

a hollow body defining an air flow conduit and including first and second open ends

Methodology Applied
Scientific EffectAir flow through conduit:

Data Source

PatentEP1984580B1An insert for a weep hole opening in a masonry wall
Publication Date: 2014.06.11 FLINT
  • EP1984580B1 patent drawingFigure 1~2
  • EP1984580B1 patent drawingFigure 3~4
  • EP1984580B1 patent drawingFigure 5

AI summary

An insert (1) for a weep hole opening in a masonry wall is disclosed. The insert (1) includes a hollow body (2) defining an air flow conduit (3) and including a first open end (4) and a second open end (5). A stainless steel mesh screen (6) extends across the conduit (3) near the first open end (4) and is adapted to prevent fire brands and sparks from passing through the body (2). A locating member, in the form of a grate (7), is hingedly connected to the body (2) adjacent the first open end (4). The screen (6) is located in a recess (8) in the rear of the grate (7) and friction between the screen (6) and the grate (7) retains the screen (6) in the recess (8). The grate (7) is formed from a material that substantially retains its spatial integrity when exposed to the heat flux profile generated by a typical forest fire, such that the grate (7) continues thereafter to locate the screen (6). The grate (7) also has a plurality of ventilation apertures (9) to allow air to pass through the air flow conduit (3). A mortar guard (10) releasably snap-lockingly engages the grate (7) to cover the ventilation apertures (9) to prevent mortar clogging the apertures (9) during rendering.