Integral Vapor-Permeable WRB Building Board for Liner-Free Installation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vapor-permeable water-resistant barrier (WRB) sheets for building construction require additional installation steps and generate waste due to the use of release liners, and they can adhere to unintended surfaces during application.
Innovation Solution
A building board with an integral WRB sheet is created by layering a WRB sheet and a polymer tie layer, made from thermally or high frequency activated fibrous web, which is non-tacky and non-blocking, allowing it to be packaged without a release liner and integrated with a board substrate, ensuring moisture vapor permeability and resistance to overdriven fasteners.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a peel-and-stick WRB sheet with adhesive and release liner is used, then the WRB sheet can be installed without mechanical fasteners, but the release liner creates considerable waste equal to the entire outer surface area of the building
Solution Approach 1:
The invention removes the release liner component entirely from the WRB sheet system. The WRB sheet is provided without any release liner, eliminating the waste problem while maintaining the ability to install without mechanical fasteners through alternative means such as self-adhering properties or integration with building boards.
Solution Approach 2:
Instead of discarding a release liner after use, the invention eliminates the need for a disposable release liner by designing a WRB sheet that can be handled and installed without one, thereby recovering what would have been waste material.
2Ease of operation
If a peel-and-stick WRB sheet with adhesive is used, then the WRB sheet can be installed without mechanical fasteners, but the adhesive causes the WRB sheet to stick to unwanted surfaces during installation
Solution Approach 1:
The invention applies adhesive only in specific localized areas rather than across the entire WRB sheet surface. This allows the sheet to be installed without mechanical fasteners while preventing unwanted sticking to surfaces during handling and installation, as the adhesive is present only where needed for bonding.
3Reliability
If a preformed WRB sheet is mechanically fastened to board substrates after wall construction, then the building envelope sealing is improved, but an additional installation step is required
Solution Approach 1:
The invention combines the WRB sheet functionality with the building board itself, creating an integral WRB sheet that is part of the building board structure. This eliminates the separate installation step of attaching a preformed WRB sheet while maintaining the building envelope sealing function, as the WRB properties are built into the board during manufacturing.
Solution Approach 2:
The WRB sheet is pre-integrated into the building board during manufacturing rather than being installed separately after wall construction. This preliminary integration maintains the reliability of building envelope sealing while improving productivity by eliminating the additional installation step.
4Reliability
If a thin WRB sheet with high vapor transmission is used, then vapor permeability is improved, but the sheet may have reduced durability and resistance to fasteners
Solution Approach 1:
The invention uses a composite structure where a thin WRB sheet providing high vapor transmission is combined with a polymer tie layer that adds strength and resistance to fasteners. The composite material maintains the vapor permeability benefits of the thin WRB sheet while the polymer layer provides the necessary mechanical strength and durability.
Solution Approach 2:
The polymer tie layer is applied locally at specific positions where fastener resistance is needed, such as at fastener penetration points or in regions subject to mechanical stress. This allows the thin WRB sheet to maintain its vapor permeability while gaining localized strength where required.
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 eliminates the need for separate WRB sheet installation, reduces waste, and maintains vapor permeability while providing effective sealing against overdriven fasteners, meeting building code requirements.
Implementation Method 1
a polymer tie layer comprising of a thermally or high frequency activated fibrous web
Implementation Method 2
a polymer tie layer comprising of a thermally or high frequency activated fibrous web
Implementation Method 3
a moisture vapor transmission rate, of at least 40 grams per square meter per 24 hours
Implementation Method 4
a Gurley Hill porosity of 250 seconds or greater
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A building board having an integral vapor-permeable water-resistant barrier (WRB) sheet, and a process for making same, and a two-material layered laminate useful for making said building board, wherein the building board comprises in order, a WRB sheet, a polymer tie layer, and a board substrate bonded together in a face-to-face relationship, the polymer tie layer comprising of a thermally or high frequency activated fibrous web and having voids through the thickness of said layer such that the polymer tie layer has a moisture vapor transmission rate through said layer of at least equal to or greater than that of the WRB sheet, the polymer of the polymer tie layer having an elastic modulus (G') greater than 1 x 106 Pa at 20° C and a softening temperature of greater than 122° F (50 C) , the softening temperature being the temperature at which the polymer elastic modulus (G') drops below 30 percent of the elastic modulus (G') of the polymer at 20° C; and wherein the moisture vapor permeability through the building board is 5 perms or greater.