Problem statement

Separation materials are used in wall construction to separate exterior from interior environments. Multiple components are generally needed to perform all the “barrier” jobs necessary (air, water, vapor, fire, sound, and thermal). Construction miscues such as reverse lapping of housewraps or water infiltration at fasteners can compromise in-service performance. To the extent that one component can do multiple jobs, other layers can be eliminated, saving on materials, labor, and miscues.

One separation layer can perform multiple functions. For example, gypsum sheathing can be both a fire barrier and a sound barrier. Air barriers can resist air leakage, water penetration, and vapor diffusion while remaining relatively thin and inexpensive. Adding more multi-functionality to separation layers would improve building performance at lower cost and complexity.

Possible approaches

Any solutions that add multi-functionality to separation materials will be considered. Traditional separation materials include board products such as gypsum board, spray-applied products such as fluid-applied air barriers, sheet goods such as building papers and felts, and polymeric water-resistive barriers. Example solutions include waterborne coatings applied with airless spray equipment or by brush/roller to wood and gypsum based sheathing substrates or coated fabric laminates for factory application onto sheathing.

Known approaches not of interest

Unless significant performance/cost breakthroughs or innovative applications can be achieved, the following materials represent known state-of-the-art and are thus not of interest:

• Common air barriers such as Polymeric housewraps (e.g. Dupont Tyvek), peel and stick membrane products (e.g. Henry Blueskin), and fluid applied products (e.g. Prosoco R-Guard)
• Factory-laminated sheathing panels (e.g. USG, Huber Engineered Woods), laminated insulation for cement board (e.g. ThermaDry), and other multi-functional wall separation materials that fail to exceed the performance, cost, or innovativeness of existing state-of-the-art solutions

Key success criteria

Required:

• Performs all existing functions (e.g. air barrier, fire resistance, etc.) without adding layers
• Adds new functionality (e.g. 3D texture for water drainage, acoustic insulation, etc.)
• Can be easily installed on-site or pre-applied to existing layers (e.g. sheathing) in-factory

Desired:

• Materials that provide superior properties such as structural support and wind load resistance
• Innovative wall assemblies that take advantage of prefabrication and modular construction
• Ability to “tune” individual properties (e.g. vapor permeance) in the factory or on-site
• Fire resistance, which is a highly desired property, is being addressed separately (Category 3)