Cavity Wall Flashing with Porous Screen for Debris Blockage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In cavity wall construction, excess mortar and debris can block weep holes, reducing the effectiveness of flashing systems and leading to water accumulation, which can cause damage and mold growth.
Innovation Solution
A flexible flashing and drainage system with a water-permeable body and drainage channels that prevent mortar and debris from passing through, while allowing water to drain through weep tabs and channels, and includes a scrim to keep channels open.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional flashing systems with weep holes are used, then water drainage is enabled, but mortar and debris block the weep holes reducing drainage effectiveness
Solution Approach 1:
The flashing member is divided into multiple segments or sections along its length, with each segment containing weep holes or drainage openings. This segmentation allows debris to fall through gaps between segments while maintaining drainage functionality, preventing complete blockage of the drainage system.
Solution Approach 2:
A screen or mesh material is introduced as an intermediary element within the flashing member, positioned between the cavity space and the weep holes. This intermediary structure allows water to pass through while blocking mortar and debris, resolving the contradiction between maintaining open drainage paths and preventing blockage by construction debris.
2Ease of operation
If weep holes are formed to drain water, then moisture removal is enabled, but the same holes become blocked by mortar droppings
Solution Approach 1:
Different portions of the flashing member have different properties: the main body provides structural support and water shedding, while specific localized regions contain screen materials or mesh that selectively allow water passage while blocking debris. This local differentiation enables the flashing to perform both drainage and debris protection functions simultaneously.
Solution Approach 2:
The flashing member incorporates porous or screened materials in strategic locations that allow water molecules to pass through while blocking larger mortar particles and debris. The porosity is carefully controlled to maintain drainage effectiveness while preventing blockage by construction debris.
3Reliability
If flashing is installed to direct water, then water management is improved, but mortar and debris reduce flashing effectiveness
Solution Approach 1:
The flashing member is designed with built-in debris protection features (screens, meshes, or segmented structures) that are installed simultaneously with the flashing itself, rather than as a separate subsequent measure. This preliminary incorporation of protective elements ensures that debris blockage is prevented from the outset while maintaining water direction control.
Solution Approach 2:
The flashing member combines different materials with complementary properties: a water-resistant base material for effective water direction, combined with porous or screened sections that filter out debris. This composite construction allows the flashing to simultaneously direct water effectively while resisting debris interference.
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 directs water away from the wall, preventing damage and mold growth by ensuring unobstructed drainage and maintaining the integrity of the cavity wall construction.
Implementation Method 1
the water permeable body has a porosity sufficient to permit water to pass therethrough but substantially insufficient to permit mortar and debris to pass therethrough
Implementation Method 2
the flashing member is flexible along the length of the flashing member and most preferably capable of being rolled, as into a cylindrical shape
Data Source
AI summary
A flashing and drainage system for use in a cavity wall construction, including a flashing member, is disclosed. The flashing member includes an upper portion and a lower portion. The flashing member may be provided in the form of a continuous roll.