Advanced Envelope Research 

for Factory Built Housing, 

Phase 3—Design 

Development and Prototyping

E. Levy, B. Kessler, M. Mullens, and P. Rath 

ARIES Collaborative 

January 2014
i 

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iii

Advanced Envelope Research for Factory Built Housing

Phase 3—Design Development and Prototyping

Prepared for:

The National Renewable Energy Laboratory

On behalf of the U.S. Department of Energy’s Building America Program

Office of Energy Efficiency and Renewable Energy

15013 Denver West Parkway 

Golden, CO 80401 

NREL Contract No. DE-AC36-08GO28308 

Prepared by: 

E. Levy, B. Kessler, M. Mullens, and P. Rath 

ARIES Collaborative 

The Levy Partnership, Inc.

1776 Broadway, Suite 2205 

New York, NY 10019 

NREL Technical Monitor: Michael Gestwick

Prepared under Subcontract No. KNDJ-0-40347-03

January 2014
iv

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v

Contents

List of Tables ............................................................................................................................................ viii

Definitions................................................................................................................................................... ix

Acknowledgments ...................................................................................................................................... x

Abstract....................................................................................................................................................... xi

Executive Summary.................................................................................................................................. xii

1 Introduction........................................................................................................................................... 1

1.1 Background..........................................................................................................................1

1.2 Project Scope .......................................................................................................................3

1.3 Research Partners.................................................................................................................3

1.3.1 Steering Committee .................................................................................................4

1.3.2 Insulation Manufacturers.........................................................................................4

1.3.3 ARIES Technical Team...........................................................................................5

1.4 Research Process..................................................................................................................5

1.5 Research Questions..............................................................................................................6

2 Mathematical and Modeling Methods................................................................................................. 8

2.1 Thermal Modeling and Cost-Benefit Analysis....................................................................8

2.2 Moisture Analysis................................................................................................................8

3 Research/Experimental Methods........................................................................................................ 9

3.1 Racking Test ........................................................................................................................9

3.1.1 Test Specimen Sampling..........................................................................................9

3.1.2 Test Procedure .........................................................................................................9

3.2 Wall Panel Mockup Demonstration.....................................................................................9

3.3 Window Framing Evaluation.............................................................................................10

3.4 Testing Apparatus..............................................................................................................10

4 Results: Phase 3—Design Development and Prototyping............................................................. 12

4.1 Overview of the Advanced Envelope Research Concept—Stud Walls With Continuous 

Exterior Insulation .............................................................................................................12

4.2 Design Development..........................................................................................................17

4.2.1 AFM Corporation...................................................................................................17

4.2.2 BASF Corporation .................................................................................................20

4.2.3 The Dow Chemical Company................................................................................26

4.2.4 Johns Manville Corporation...................................................................................28

4.2.5 Saint-Gobain/CertainTeed .....................................................................................32

4.3 Production Analysis...........................................................................................................35

4.4 Thermal and Cost Benefit Analysis...................................................................................36

4.5 Moisture Analysis..............................................................................................................38

4.6 Prototyping and Testing.....................................................................................................41

4.6.1 Location and Participants.......................................................................................42

4.6.2 Racking Tests.........................................................................................................42
vi

4.6.3 Process Mockup Evaluation and Observation .......................................................43

4.6.4 Window Construction Assessment ........................................................................44

5 Discussion........................................................................................................................................... 46

5.1 Stud Walls With Styrofoam...............................................................................................46

5.1.1 Construction Detailing...........................................................................................46

5.1.2 Installing Windows and Doors...............................................................................47

5.1.3 Fasteners ................................................................................................................49

5.1.4 Assembly/Production.............................................................................................51

5.1.5 Racking Test Results..............................................................................................53

5.2 Stud Walls With Foam-Control Nailbrace.........................................................................56

5.2.1 Construction Detailing...........................................................................................57

5.2.2 Installing Windows and Doors...............................................................................58

5.2.3 Fasteners ................................................................................................................61

5.2.4 Assembly/Production.............................................................................................64

6 Conclusions ........................................................................................................................................ 67

References................................................................................................................................................. 69

Appendix A: Detailed Test Description................................................................................................... 71

Appendix B: Equipment and Material Needs ......................................................................................... 76
vii 

List of Figures

Figure 1. Plan view of testing apparatus ................................................................................................ 10

Figure 2. Front elevation (left) and side elevation (right) of testing apparatus .................................. 11

Figure 3. Corner detail of testing apparatus .......................................................................................... 11

Figure 4. Stud wall with exterior insulation, Design 1 (climate zone 5) .............................................. 16

Figure 5. Stud wall with exterior insulation, Design 2 (climate zones 6, 7, and 8)............................. 17

Figure 6. Stud wall with exterior insulation, Design 3 (climate zones 6, 7, and 8)............................. 17

Figure 7. Foam-Control Nailbrace Concept A, Design 1 (climate zone 5)........................................... 18

Figure 8. Foam-Control Nailbrace Concept A, Design 2 (climate zones 6, 7, and 8) ......................... 18

Figure 9. Foam-Control Nailbrace with let-in bracing (without WRB) ................................................. 18

Figure 10. Foam-Control Nailbrace - top view (without WRB).............................................................. 18

Figure 11. NEOPOR Concept A, Design 1 (climate zone 5) .................................................................. 21

Figure 12. NEOPOR Concept A, Design 2 (climate zones 6, 7, and 8)................................................. 21

Figure 13. NEOPOR Concept B, Design 1 (climate zone 5) .................................................................. 21

Figure 14. NEOPOR Concept B, Design 2 (climate zones 6, 7, and 8)................................................. 21

Figure 15. NEOPOR Concept C, Design 1 (climate zone 5) .................................................................. 22

Figure 16. NEOPOR Concept C, Design 2 (climate zones 6, 7, and 8)................................................. 22

Figure 17. NEOPOR Concept D, Design 1 (climate zone 5) .................................................................. 22

Figure 18. NEOPOR Concept D, Design 2 (climate zones 6, 7, and 8)................................................ 22

Figure 19. NEOPOR R-value at 75°F and 40°F ....................................................................................... 25

Figure 20. Stud wall with Styrofoam, Design 1 (climate zone 5)......................................................... 27

Figure 21. Stud wall with Styrofoam, Design 2 (climate zones 6, 7, and 8) ....................................... 27

Figure 22. ValuTherm Concept A (climate zones 5, 6, 7, and 8)........................................................... 29

Figure 23. AP foil-faced sheathing Concept B (climate zones 5, 6, 7, and 8) ..................................... 29

Figure 24. SIS sheathing Concept C (climate zones 5, 6, 7, and 8) ..................................................... 29

Figure 25. Stud wall with faced CertaPro, Design 1 (climate zone 5) .................................................. 33

Figure 26. Stud wall with faced CertaPro, Design 2 (climate zones 6, 7 and 8).................................. 33

Figure 27. WUFI results for wall with R-10 (2 in. XPS) insulation in International Falls .................... 40

Figure 28. WUFI results for wall with R-5 (1 in. XPS) insulation in International Falls ...................... 41

Figure 29. Detail 1—Window frame bearing on foam............................................................................ 44

Figure 30. Detail 2—Window framing with buck lumber....................................................................... 45

Figure 31. Detail 3—Window framing with metal L-section.................................................................. 45

Unless otherwise noted, all figures were created by the ARIES team.
viii

List of Tables

Table 1. Desired Properties of Advanced Wall Designs With Composite Insulative Sheathing....... 13

Table 2. Foam-Control Nailbrace—Sizes and Weights ......................................................................... 19

Table 3. NEOPOR—Physical Properties ................................................................................................. 23

Table 4. R-Value of NEOPOR Rigid Thermal Insulation........................................................................ 24

Table 5. NEOPOR—Sizes and Weights................................................................................................... 25

Table 6. Styrofoam—Sizes and Weights................................................................................................. 28

Table 7. JM Products—Physical Properties........................................................................................... 30

Table 8. ValuTherm—Sizes and Weights................................................................................................ 31

Table 9. AP Foil-Faced Insulation—Sizes and Weights ........................................................................ 31

Table 10. AP Foil-Faced Insulation—Weather Resistive Properties.................................................... 32

Table 11. CertaPro—Physical Properties ............................................................................................... 34

Table 12. CertaPro—Sizes and Weights ................................................................................................. 35

Table 13. Impact Summary—Work Content ........................................................................................... 36

Table 14. Allowable Cost of Insulative Sheathing To Qualify as Cost Effective ................................ 37

Table 15. Comparison of U-Values.......................................................................................................... 38

Table 16. Racking Tests—Stud Walls With Styrofoam ......................................................................... 43

Table 17. Racking Tests—Stud Walls With Foam-Control Nailbrace .................................................. 43

Table 18. Process Mockups—Stud Walls With Styrofoam ................................................................... 43

Table 19. Process Mockups—Stud Walls With Foam-Control Nailbrace ............................................ 44

Table 20. Racking Test Results—Stud Walls With Styrofoam ............................................................. 54

Table 21. Racking Test Results—Stud Walls With Foam-Control Nailbrace ...................................... 65

Table 22. Details on Racking Tests—Stud Walls With Styrofoam ....................................................... 72

Table 23. Details on Racking Tests—Stud Walls With Foam-Control Nailbrace................................ 73

Table 24. Details on Mockups—Stud Walls With Styrofoam................................................................ 74

Table 25. Details on Mockups—Stud Walls With Foam-Control Nailbrace......................................... 75

Table 26. Fasteners and Associated Tools (Senco Products) ............................................................. 76

Table 27. Fasteners and associated tools (FastenMaster products)................................................... 77

Unless otherwise noted, all tables were created by the ARIES team.
ix

Definitions

BEopt Building Energy Optimization

CI Continuous insulation

EPS Expanded polystyrene

XPS Extruded polystyrene

HUD U.S. Department of Housing and Urban Development

IECC International Energy Conservation Code

IRC International Residential Code

JM Johns Manville

N/A Not available

OEM Original equipment manufacturer

OSB Oriented strand board

pcf per cubic foot

plf per linear foot

RD&D Research, design, and development

SIP Structural insulated panel

VR Vapor retarder

WRB Weather resistive barrier

WUFI Wärme und Feuchte instationär (Transient heat and moisture)
x

Acknowledgments

ARIES Collaborative would like to recognize the support of the U.S. Department of Energy’s 

Building America Program and Michael Gestwick of the National Renewable Energy Laboratory

for technical guidance. We also would like to acknowledge the research direction provided by 

the factory built housing industry represented by leading home manufacturers. We were 

fortunate to have some of the prominent insulation manufacturers of the nation weighing in on 

the credibility of the technology options to make them more viable and cost effective.
xi

Abstract

The Advanced Envelope Research effort will provide factory homebuilders with high 

performance, cost-effective alternative envelope designs. In the near term, these technologies 

will play a central role in meeting more stringent energy code requirements. For manufactured 

homes, the thermal requirements, last updated by statute in 1994, will move up to the more 

rigorous International Energy Conservation Code (IECC) 2012 levels in 2013, the requirements 

of which are consistent with site built and modular housing. This places added importance on 

identifying envelope technologies that the industry can implement in the short timeframe. The 

primary goal of this research is to develop wall designs that meet the thermal requirements based 

on 2012 IECC standards. Given the affordable nature of manufactured homes, impact on first 

cost is a major consideration in developing the new envelope technologies.1

This work is part of a four-phase, multiyear effort. Phase 1 identified seven envelope 

technologies and provided a preliminary assessment of three selected methods for building high 

performance wall systems. Phase 2 focused on the development of viable product designs, 

manufacturing strategies, addressing code and structural issues, and cost analysis of the three 

selected options. An industry advisory committee helped critique and select the most viable 

solution to move further in the research—stud walls with continuous exterior insulation. Phase 3, 

the subject of the current report, focused on the design development of the selected wall concept 

and explored variations on the use of exterior foam insulation. The scope also included material 

selection, manufacturing and cost analysis, and prototyping and testing. Phase 4, starting in 2013, 

will complete the testing, cull down to designs with the greatest market potential, and begin to 

clear the code, production, and design hurdles to commercial use. 

Key words

Factory built housing

Manufactured housing

Modular housing

Research, design, and development

Advanced envelope research

Energy efficiency

Envelope technology

Advanced wall strategy

Walls with exterior sheathing

Continuous exterior insulation

 1 First cost impacts are more meaningful for buyers of modestly priced homes and therefore decisions about 

efficiency measures must be made in light of both impact on cost and cost effectiveness.
xii

Executive Summary

The Advanced Envelope Research project seeks to improve the energy performance of new 

factory built homes. Factory building divides into manufactured and modular homes. Most 

factory built homes are termed “manufactured” and are constructed under the nationally preemptive manufactured housing standards (referred to as the U.S. Department of Housing and 

Urban Development standards), which were last updated in 1994. The U.S. Department of 

Energy is currently working on changes to these standards that are anticipated to be enacted in 

2013 and are expected to be based on IECC 2012. The industry currently has no broadly 

implemented, competitive options for meeting the anticipated thermal provisions of these 

standards. Modular homes are built in a factory using methods that are similar to, or the same as,

manufactured homes. Modular homes generally meet the same state-based energy standards as 

site built homes, standards that are also in the process of becoming more stringent.

In response, this effort is intended to create and demonstrate new envelope design and building 

practices that are cost effective, that can be successfully applied in a factory setting, and that 

result in substantial reductions in energy use. This research will yield new practices for building 

envelope components that meet these criteria and initiate the process of moving these practices 

into commercial use. 

The primary goal of this research is to achieve a target wall thermal value based on future code 

requirements. The current work is part of a multiyear development effort, divided into four 

phases. Phase 3, the subject of this report, focused on the design development, prototyping, and 

testing of high performance wall systems sharing a common characteristic: all employed stud 

wall construction with continuous exterior insulation. The research involves key industry

stakeholders as active partners whose input and contribution to the effort are integral to 

accomplishing the project goals. Major stakeholders in Phase 3 included insulation 

manufacturers, companies that eventually will be suppliers of products specified for the options 

and the factory built home manufacturers that are the end users. Insulation companies played a 

key role in the design development. Selected designs were prototyped and tested at a partner 

manufacturing plant. Key results include performance analysis and selection of designs that will 

move forth to the next phase of the project. With the impending code changes, the factory built 

manufacturing companies are keen to see the research result in cost-effective solutions that could 

be taken to market quickly. In short, all of the stakeholders are heavily invested in seeing this 

work succeed and the results put into practice.
1

1 Introduction

The Advanced Envelope Research project seeks to improve the energy performance of new 

factory built homes, a segment of the housing industry that accounts for about 12%–14% of the 

nation’s total annual housing sales.2 The largest segment of the factory building industry, 

manufactured homes, historically has had to meet energy standards less stringent than current 

International Energy Conservation Code (IECC)-based codes. As a consequence, the industry 

has evolved few cost-effective options for reaching ambitious energy efficiency targets, such as 

the Building America goals. This research, design, and development (RD&D) effort will fill this 

void by creating and demonstrating new design and building practices that minimize cost, that 

can successfully be applied in a factory setting, and that result in substantial reductions in energy 

use. The research will yield new practices for building envelope components that meet these 

criteria and initiate the process of moving these practices into commercial use.

The majority of factory built housing manufacturers have been slow to adopt new building 

products and technologies on their own for many reasons, including: (1) the development costs 

are prohibitively high for any single manufacturer; (2) developing proprietary envelope solutions 

would be difficult to defend in the market, meaning that the RD&D investment by one company 

would benefit competitors; and (3) while most companies have engineering staff, they lack a

tradition of building technology RD&D and are ill-equipped to conduct the type of cross cutting 

research that involves the complex set of interrelated technical issues envisioned for this project.

Success of the proposed work—the demonstration of how advanced envelope designs can 

replace conventional frame construction without a significant impact on total cost—will yield 

cornerstone technologies the industry will need in moving toward the nation’s ambitious energy 

efficiency goals. While the results of this research will have immediate application to 

manufactured homes, the technologies developed will have relevance for modular construction 

as well. Modular homes are subject to similar factory construction issues and manufacturing 

constraints and generally have a higher price point than manufactured housing, allowing for 

greater design flexibility.

1.1 Background

Lacking the regulatory pressures that would necessitate high performance envelope designs and 

marketing homes to buyers with little discretionary buying power, the factory built housing has 

been slow to develop envelope construction practices that approach Building America targets. As 

a result, the industry has few proven and cost-effective building solutions for responding to a fast 

changing marketplace that is demanding greater energy efficiency and impending regulatory 

changes that will require them.

3

 2 Estimate derived from the National Modular Housing Council’s Quarterly Modular Housing Report and the 

Manufactured Housing Institute’s Monthly Economic Reports (2010). Source of the reports—

www.manufacturedhousing.org/reports/ (available to Manufacturing Housing Institute members only). The 

percentage share shown is new factory built homes relative to the number of total new houses sold. This figure is in 

terms of number of housing units.

3 The modular housing industry has limited prior experience building walls with continuous exterior insulation, the 

focus of this research effort. One of the project goals is to develop simple designs with few materials that perform 
2

Most factory built homes are constructed under the nationally pre-emptive manufactured housing 

standards (also referred to as the U.S. Department of Housing and Urban Development [HUD]

standards). The thermal provisions of the standards were last updated in 1994 (HUD 1994). As a 

result, manufactured housing currently lags behind other types of housing in terms of energy 

performance, particularly in states that routinely adopt the most recent version of the IECC. The 

U.S. Department of Energy is currently working on changes to the HUD standards that are 

anticipated to set the bar for performance based on the IECC 2012, that, when implemented, are 

expected to result in major changes in how the industry approaches thermal envelope design and 

construction. 

Although the potential benefits of proving high performance envelope component designs for 

factory application are huge, the technical hurdles for factory builders are formidable.

Implementing changes to envelope components can engender a host of major changes in plant 

layout, workflow, materials handling, and safety issues. Potentially, some of the proposed 

changes would increase production rates while improving quality, magnifying the benefits of this 

research. Other elements of the needed research include assessing the impact of changes on 

structural performance, moisture dynamics, integration of services, and code acceptance. This 

research effort sets the stage for elevating factory production to address these factors and fully 

and seamlessly incorporating advanced methods into the industrialized building fabric.

The home building industry generally lacks a tradition of research, and home manufacturers in 

particular have limited internal expertise and capacity to develop new technologies. Further

constraining individual companies is the lack of discretionary spending on new product 

development due, in part, to the massive losses that every company has suffered over the last 

decade. As noted, the dynamics have changed and the industry must now find cost-effective and 

high performance envelope solutions to meet future code requirements and market pressures.

The industry’s initial attempts to develop cost-effective approaches to improving energy 

performance (including the use of structural insulated panels [SIPs] and other open and closed 

cell insulation products) convinced many in the industry that such technologies have the 

potential to revolutionize manufacturing practice. However, the resources (financial and 

technical) needed to tackle the myriad interrelated challenges are well beyond the capacity and 

skills of a single or even a group of manufacturers. The other drag on innovation is the fact that 

the industry is highly competitive and advances underwritten by a single company are readily 

adopted by other manufacturers, diluting the value of the research investment. Patents are few 

and expensive to defend, in part explaining why most buildings-related research is conducted by 

product manufacturers, not home building companies.

This work initiates a new direction for Building America activities. Introducing new envelope 

construction practices in a factory setting will provide valuable insights into how high 

performance products can be applied to home building, yielding new measure guidelines and 

potentially identifying practices that can be used by site and componentized homebuilders.

 

multiple functions minimizing the number of individual products that must be purchased, inventoried, and installed 

by the plant, saving cost in both handling and main line construction time. 
3

1.2 Project Scope

The study is exclusively focused on advancing envelope design’ and the current work is part of a 

multiphase effort to improve the performance of wall components. The team recognizes that 

having viable and cost-effective envelope technologies is a prerequisite in formulating whole 

building solutions. The current research effort focuses on factory built homes located in IECC 

2009 climate zones 5 and higher. Insulation requirements underwent significant changes for 

these northern, primarily heating-dominated climate zones that will benefit most from these 

research findings. 

The approach to the project and scope is shaped by the following three overarching 

considerations:

1. Minimize cost, maximize performance: One of the major challenges in the 

development process is creating a product design and fabrication method that minimizes 

total cost while maximizing product performance. The product and process designers 

each start with a set of goals but must engage in a development process that arrives at a 

common, integrated, and optimized solution. The process of bringing diverse goals to a 

common development process, in which several disciplines simultaneously re-engineer 

the building product and process and work to integrate and synergize their solutions, is 

often referred to as concurrent engineering.

4

2. Reinvent the whole system: This research work is being driven by the unique 

requirements of factory homebuilding. Researchers seek synergies among building 

materials, automated production equipment, and information technology. Then, guided 

by the principles of lean production, researchers will explore how the whole system can 

be reinvented to dramatically improve quality, energy efficiency, safety, cost 

effectiveness,

5 productivity, and design flexibility.

3. System integration: In all homes, but particularly in factory built housing, performance 

of systems, subsystems, and components is dependent on other systems within the 

structure, and improving performance in one area has collateral impacts elsewhere. For 

example, changes in the envelope subsystem intended to improve energy efficiency may 

affect the production process and may alter the structural characteristics of the home. 

Optimization of any single part of the home therefore depends on balancing 

considerations elsewhere. The team employs a systems approach designed to find 

combinations of changes that together improve overall performance when gauged relative 

to an objective baseline.

1.3 Research Partners

This effort is cooperatively sponsored by the Systems Building Research Alliance. Technical 

direction is provided by an industry-led Steering Committee acting under the Systems Building 

Research Alliance umbrella and consisting mainly of factory building company representatives. 

 4 Concurrent engineering benefits factory built housing more than other less industrialized forms of housing for 

several reasons, including the fact that the economics of the plant construction process are far more dependent upon 

speed, coordination of trades, and dimensional precision. In addition, quality control and coordination of the trades 

is more easily accomplished in the factory than at the building site.

5 Cost effectiveness is a general expression intended to convey that costs and benefits have been balanced using 

some generally accepted econometric process. 
4

Participating insulation manufacturers are key contributors to the work and the concepts 

developed. ARIES team members facilitate the work and provide technical support, analysis, 

evaluation and documentation. Members of the research team are listed below:

1.3.1 Steering Committee

Michael Wade, Cavalier Homes, Committee chair

Ronnie Richards, American Homestar Corp.

Jayar Daily, American Homestar Corp.

John Meredith, Beracah Homes, Inc.

Jerome Alexander, BlueLinx Corporation

Mark Klaus, Cavco Industries, Inc.

Manuel Santana, Cavco Industries, Inc.

Phillip Copeland, Champion Home Builders, Inc.

David French, Champion Home Builders, Inc.

Bill Stamer, Champion Home Builders, Inc.

Tony Watson, Champion Home Builders, Inc.

Mark Ezzo, Clayton Homes

Gary Butler, Commodore Homes, Inc.

Nader Tomasbi, Commodore Homes, Inc.

Robert Bender, Commodore Homes, Inc.

Jim Dunn, Eagle River Homes, Inc.

Alan Behrent, Excel Homes, Inc.

Delma Sheaffer, Excel Homes, Inc.

Bill Langdon, Forest River Housing, Inc.

Luca Brammer, Hallmark—Southwest Corp.

Mark Tackett, Louisiana Pacific Corporation

Lois Starkey, Manufactured Housing Institute

Mike Clementoni, Muncy Homes, Inc.

Rich Bird, Muncy Homes, Inc.

Woody Bell, Nationwide Custom Homes

Andy Miller, Nationwide Custom Homes

Eric Tompos, NTA, Inc.

Bert Kessler, Palm Harbor Homes

Bryan Huot, Preferred Building Systems

Richard Shives, Premier Builders

Terry Dullaghan, Senco 

1.3.2 Insulation Manufacturers

Mike Tobin, AFM Corp.

Paul Fox, BASF

Brian Lieburn, Dow Corp.

Bryan Mallon, Dow Corp.

Francis Babineau, Johns Manville Corp.

Craig Marden, Owens Corning

Daniel Small, Saint-Gobain/CertainTeed
5

1.3.3 ARIES Technical Team

Emanuel Levy, The Levy Partnership, Inc.

Michael Mullens, The Levy Partnership, Inc.

Pournamasi Rath, The Levy Partnership, Inc.

1.4 Research Process

The research will develop the next generation of envelope component designs for the factory 

building industry. This work consists of identifying alternative options, critically evaluating their 

potential to meet a set of performance goals, selecting option(s) for development, developing a 

design/engineering solution for the option(s), and testing and evaluation. The project spans 

several years and is divided into four phases as follows:

Phase 1. Identification and characterization of options. Completed in 2011, this phase 

identified a wide range of innovative envelope technologies that were culled down to 

a short list of three methods for building high performance wall systems.

Phase 2. Preliminary design. Completed in January 2012, Phase 2 focused on the 

development of viable product designs, manufacturing strategies, addressing code and 

structural issues, and cost analysis of the three innovative wall concepts. An industry 

advisory committee was convened to help critique and select the most viable solution.

Phase 3. Design development and prototyping. Phase 3, the subject of the current report, 

focused on design development exploring variations on the use of exterior foam 

insulation, one of the three core concepts. The scope of work also included material 

selection, manufacturing and cost analysis, and prototyping and testing.

Phase 4. Proof of concept and market readiness. Phase 4, scheduled to start in late-2013, 

will complete the testing of wall designs that feature exterior foam insulation. The 

work will identify designs with the greatest market potential, and begin to clear the 

code, production, and design hurdles to commercial use.

The research methods and results of Phases 1 and 2 are discussed in detail by Levy et al. (2012).

Phase 1 of the Advanced Envelope Research was initiated by an industry advisory committee 

meeting held in early 2011. Leading insulation companies were invited to present envelope 

solutions with project potential. The presentations provided numerous ideas that were debated 

and discussed by the industry advisory committee. The concepts were honed by the ARIES team 

and narrowed to a short list of seven candidate technologies, as follows:

• SIPs for ceilings

• SIPs for walls

• Stud wall with insulating sheathing board

• Unvented attic with continuous exterior insulation

• Flash and batt wall construction

• Poured closed cell foam

• Innovative new floor design.
6

Following a preliminary design development of the seven identified options, a qualitative

assessment pinpointed the benefits and drawbacks of each of the technologies when used in the 

factory building setting. Criteria for comparison included energy performance, 

manufacturability, code compliance, and cost. The advisory committee and industry experts rated 

the options and selected the following for subsequent research:

• SIPs for walls

• Stud walls with continuous exterior insulation

• Flash and batt wall construction.

In Phase 2, the three concepts were further developed and refined. The characterizations 

provided sufficient detail to allow a detailed assessment of the costs associated with adopting the 

technology, impact on current manufacturing processes, value of the technology in helping to 

comply with stringent energy codes (now and in the future), market appeal, and other attributes 

essential for commercial acceptance. The research in this phase included a “base case” wall 

design that would likely be used by industry in the absence of an advanced solution to meet 

stringent energy standards.

The ARIES technical team and the industry advisory committee discussed the findings,

identifying those that were most cost effective and had potential wide market appeal and 

application (potentially attractive to most manufacturers). Subsequently, one technology—based 

on the use of continuous exterior sheathing combined with batt insulation—was deemed by the 

committee as having the greatest commercial potential. The analysis of SIPs helped the industry 

representatives recognize that this technology has real advantages that were not manifest when 

used for wall construction, but that might be viable for other components. The committee also 

concluded that a major redesign of the roof and floor system used by most builders of 

manufactured homes continues to be a crucial part of the effort to improve overall envelope 

thermal performance. Further developing the wall with exterior insulative sheathing is the 

subject of the current work which includes exploring variations on the use of different insulation 

products resulting in multiple wall assembly combinations. 

1.5 Research Questions

This phase of the research sought to answer the following questions:

• What options exist for building wall components that incorporate off-the-shelf or readily 

developable insulative sheathing materials that minimize cost, substantially improve 

thermal performance and leverage the inherent efficiencies of factory production?

• What are the detailed performance characteristics of such a wall system?

• How do these options compare with regard to structural properties? Specifically, how can 

they contribute to wall shear resistance?

• For walls with insulative sheathing, what are the preferred strategies for controlling 

moisture when used in a factory built assembly? In particular, what are the desired vapor 

retarder (VR) properties of the materials and how is this best achieved through design and 

product fabrication and assembly?
7

• What are the major technical hurdles to using insulative sheathing in the factory 

environment? To what extent can these barriers be surmounted by further research and 

product development?
8

2 Mathematical and Modeling Methods

2.1 Thermal Modeling and Cost-Benefit Analysis

Thermal modeling and cost-benefit analysis were performed using BEopt (Building Energy 

Optimization), software developed by the National Renewable Energy Laboratory for the 

purpose of selecting among measures based on their relative cost effectiveness. However, one of 

the primary goals of research is to achieve a fixed wall thermal value based on future code 

requirements. Therefore, the measure value (thermal resistance) was fixed and BEopt was 

instead used to identify a target cost, a figure that would meet predefined cost-benefit goals while 

achieving the stipulated measure thermal value. Of course, the effort was designed to leverage 

factory building methods in ways that minimize costs, recognizing that the target wall thermal 

values were fixed by statute and that even at the lowest achievable cost the measure might not be 

cost effective. Results of the analysis are provided in Section 4.4.

2.2 Moisture Analysis

WUFI (Wärme und Feuchte instationär), used for moisture analysis, is a software family that 

allows realistic calculation of the transient coupled one- and two-dimensional heat and moisture 

transport in multilayer building components exposed to natural weather (ORNL 2013). It was 

developed by Institut Bauphysik and is based on the newest findings regarding vapor diffusion 

and liquid transport in building materials. The research is being conducted in the context of 

different regulatory frameworks for modular and manufactured homes. Modular homes must 

meet the same code as site built homes. While the requirement varies by location, generally the 

prevailing code requirements are based on a version of the International Residential Code (IRC). 

Manufactured homes conform to the HUD Standards. In selecting wall characteristics, 

researchers identified a provision in the IRC (Section R702.7) that eliminates the Class I or II

VR requirement on the interior (a cost saving measure) if, among other conditions, exterior 

insulated sheathing is used. (While this provision is not currently provided for in the HUD 

Standards, the current research and work of other Building America teams could provide the 

technical basis for recommending to HUD a future change in the standards.) Therefore, part of 

the purpose of the moisture analysis was to assess how moisture flow is impacted if the interior 

materials provide little resistance to vapor transmission (Class III) coupled with exterior 

materials that can be Class I, II, or III VRs. Results of the analysis are provided in Section 4.5.
9

3 Research/Experimental Methods

Experimental methods for this research project comprised the following tests/evaluation 

methods:

• Racking test to evaluate structural capacity

• Wall panel mock-up demonstration

• Window framing assessment.

Multiple iterations of each selected wall option were subject to testing and mockups.

3.1 Racking Test

A racking test was performed on developed wall designs to evaluate structural compliance with 

ASTM E72-80 or E564 as required for compliance under the HUD standards. The objective of 

the test was to determine the ultimate racking capacity of a framed shearwall with or without 

gypsum board adhered to one side and siding nailed to the opposite side.

3.1.1 Test Specimen Sampling

The racking tests were performed along the lines of the ASTM E564 testing protocol. Unlike the 

ASTM sampling protocol where the procedure is performed on three test specimens, testing for 

this research project was performed on one specimen wall only (but there were multiple wall 

options tested). This was largely owing to the scope of work in the current phase of the research

which is limited to preliminary technology assessment. Testing was performed as a comparative 

study between selected wall options and not so much as certifying them for code compliance.

3.1.2 Test Procedure

Each wall specimen was tested for ultimate load testing as per the requirements outlined in 

Manufactured Home Construction and Safety Standards 3280.401(b). The racking load was 

applied parallel to and at the top plate of the wall. The load was applied continuously at a 

uniform rate in increments of 1000 lb. The duration of each load application was maintained for 

10 min before taking load and deflection readings. After the load was removed any residual 

deflection was recorded after 5 min of recovery. The specimen was reloaded to the next higher 

load above the back off load. The loading and unloading cycles were continued until ultimate 

load or maximum allowable deflection was reached.

Ultimate load is defined as the inability of the specimen to hold any additional load. The target 

design load for the wall options was 210 plf.

6

3.2 Wall Panel Mockup Demonstration

Wall panel mockup demonstration was conducted to assess the fabrication sequence and 

manufacturability of selected wall options. The panels were assessed based on the following 

factors: assembly, production, installing doors and windows, fastening techniques, building 

details, and other related issues.

 6 210 plf is standard structural target for HUD code homes in wind zone 1 covering most of the United States.
10

3.3 Window Framing Evaluation

Various window framing options were explored to be part of the process mockup at the 

demonstration. Of a significant number of developed details, three framing options (see Section 

4.6.4) were selected that were innovative, functional, and adaptive to factory built construction.

3.4 Testing Apparatus

The apparatus for each test consisted of a boxed frame that measured 8 ft × 2 ft, 8 in. in plan and 

8 ft high. The front panel (sized 8 ft × 8 ft) of each frame was used for conducting racking tests 

and demonstrating process mockups. Studs in panels were 2 in. × 4 in. for R-10 walls and 2 in. × 

6 in. for R-5 walls. A partial floor and partial roof were fabricated for each frame to receive the 

walls. Sidings and insulation varied depending on the wall combination being tested (see Section

4.6). A plan view of the boxed frame is shown in Figure 1.

Figure 1. Plan view of testing apparatus

Figure 2 shows the front and side elevations of the testing apparatus framework. The front panel 

included a door and a window for the process mockups only. Panels used for racking tests did 

not have any wall openings.
11

Figure 2. Front elevation (left) and side elevation (right) of testing apparatus

Figure 3 shows the corner detail of the testing apparatus.

Figure 3. Corner detail of testing apparatus
12

4 Results: Phase 3—Design Development and Prototyping

Phase 3 of the Advanced Envelope Research focused on the detailed design development and 

prototyping of wall options based on one of the three core concepts identified in the prior phase 

of the work. In Phase 2, designs were developed for three high thermal performance envelope 

technologies: SIPs for walls, stud walls with continuous exterior insulation, and flash and batt 

wall construction. The “stud walls with continuous exterior insulation” option was selected by 

the industry-led Steering Committee as the most viable option to move further in the research 

process.

The objective of this phase was to explore variations on the use of exterior foam insulation and 

develop wall options based on superior insulation products so that wall performance and 

functionality are optimized for factory built housing. This information provided the basis for the 

industry committee to compare and contrast the options to select promising designs for 

prototyping and testing, also conducted in this phase of research.

4.1 Overview of the Advanced Envelope Research Concept—Stud Walls With 

Continuous Exterior Insulation

Advanced wall designs were developed with the goal of meeting the prescriptive requirements of 

the IECC 2012 standards. The industry committee developed a detailed set of wall performance 

specifications as guidance to the insulation suppliers in recommending design options. These are 

considered ideal attributes that potentially would be satisfied by a single product incorporated 

into the overall wall design. Insulation suppliers were encouraged to recommend composite 

panel concepts based on their proprietary materials that satisfied as many of the conditions as 

possible. The goal in packing multiple attributes into a single product is to minimize the number 

of individual products that must be purchased, inventoried, and installed by the plant, saving cost 

in both handling and main line construction time. The desired attributes are described in Table 1.
13

Table 1. Desired Properties of Advanced Wall Designs With Composite Insulative Sheathing

Properties

IECC Climate Zone 5 IECC Climate Zones 6, 7, and 8

Reference Design Design 1 Design 2 Design 3

Required Properties

Insulative 

Sheathing 

R-Value

Not applicable R-5 R-10 R-5

Vapor 

Management7

Class I/II VR on 

inside.

Preferred: Class I/II insulative 

sheathing on exterior with Class 

III VR on inside.

Alternative:8 Class III insulative 

sheathing on exterior; Class I/II 

VR on inside.

Preferred: Class I/II insulative 

sheathing on exterior with 

Class III VR on inside.

insulative sheathing on exterior; 

Class I/II VR on inside.

Class I/II VR on inside; 

Insulative sheathing perm 

rating at least >1.

Desired Properties

Rain Water 

Management/

Water

Resistive 

Barrier

(Note: Drainage 

plane shall be 

No. 15 asphalt 

layer compliant 

with ASTM D 

226 Type 1 or 

other approved 

Install drainage plane 

to the exterior side of 

the framing/ 

insulation. Air space 

recommended with 

drainage plane

(Lstiburek 2006).

Preferred: Using the insulative 

sheathing as a drainage plane 

(subject to demonstrated longterm durability of the sheathing 

or facing material)

(Lstiburek 1999).

Alternative: Install drainage 

plane to the exterior/interior of 

the insulative sheathing. Air 

space recommended with 

drainage plane.

Preferred: Using the insulative 

sheathing as a drainage plane 

(subject to demonstrated longterm durability of the sheathing 

or facing material).

Alternative: Install drainage 

plane to the exterior/interior of 

the insulative sheathing. Air 

space recommended with 

drainage plane.

Preferred: Using the 

insulative sheathing as a 

drainage plane (subject to 

demonstrated long-term 

durability of the sheathing 

or facing material).

Alternative: Install 

drainage plane to the 

exterior/interior of the 

insulative sheathing. Air 

space recommended with 

drainage plane.

 7 Class I VR: 0.1 perms or less (Vapor impermeable); Class II VR: ≤ 1.0 perms and > 0.1 perm (Vapor semi-impermeable); Class III VR: ≤ 10 perms and >n 1.0 

perm (Vapor semi-permeable); Not a VR: > 10 perms (Vapor permeable).

8 Mandatory requirement for HUD code homes.
14

Properties

IECC Climate Zone 5 IECC Climate Zones 6, 7, and 8

Reference Design Design 1 Design 2 Design 3

water resistive 

barrier.

9

)

Air Infiltration 

Resistance

Install a continuous air 

infiltration barrier on 

the exterior side of the 

framing/ insulation.

Install a continuous air 

infiltration barrier on the 

exterior/interior of the insulative 

sheathing.

Install a continuous air 

infiltration barrier on the 

exterior/interior of the 

insulative sheathing.

Install a continuous air 

infiltration barrier on the 

exterior/interior of the 

insulative sheathing.

Shear 

Resistance10, 11

(non-wind zone 

areas)

Sheathing on the 

exterior side with 

structural strength of 

210 plf minimum.

Sheathing on the exterior side 

with structural strength of 210 

plf minimum.

Sheathing on the exterior side 

with structural strength of 210 

plf minimum.

Sheathing on the exterior 

side with structural 

strength of 210 plf 

minimum.

 9 R703.2 Water-resistive barrier. IRC 2012.

10 Using the gypsum board with a proper adhesive is expected to provide sufficient shear resistance in most areas, at least for homes built under the HUD 

standards. For modular homes, additional shear resistance may need to be provided by the materials placed outside of the framing, whether as a property of the 

insulative board (preferred) or through the use of an additional material, such as OSB.

11 Focus on shear strength is a reflection of the industry need to build homes that stand up to racking during transportation. 
15

Properties

IECC Climate Zone 5 IECC Climate Zones 6, 7, and 8

Reference Design Design 1 Design 2 Design 3

Additional Specifications

Cladding 

Attachment

Direct cladding attachment 

to structural sheathing.

Preferred: Direct cladding 

attachment through 

sheathing into the studs 

using extra-long fasteners 

(nails, screws etc.) that can 

be collated. Certain 

fasteners allow up to 4 in.

of foam sheathing 

thickness.

Alternative: Using furring 

or hat-channel over foam 

sheathing to support the 

siding.

Preferred: Direct cladding 

attachment through sheathing 

into the studs using extra-long 

fasteners (nails, screws etc.) 

that can be collated. Certain 

fasteners allow up to 4 in. of 

foam sheathing thickness.

Alternative: Using furring or 

hat-channel over foam 

sheathing to support the siding.

Preferred: Direct cladding 

attachment through 

sheathing into the studs 

using extra-long fasteners 

(nails, screws etc.) that 

can be collated.

Other Wall Characteristics

Siding Material Vinyl or fiber cement Vinyl or fiber cement Vinyl or fiber cement Vinyl or fiber cement

Nominal 

Insulation R-21 HD batt insulation R-13 batt insulation R-13 batt insulation R-21 HD batt insulation

Framing 2 in. × 6 in. 2 in. × 4 in. 2 in. × 4 in. 2 in. × 6 in.

Frame 

Spacing12 16 in. o.c. 24 in. o.c. 16 in. o.c. 24 in. o.c. 16 in. o.c. 24 in. o.c. 16 in. o.c. 24 in. o.c.

Wall U-Value 0.052 0.050 0.054 0.053 0.042 0.041 0.040 0.039

 12 Assumed framing fraction – 14.98% for studs at 16 in. o.c. and 12.15% for studs at 24 in. o.c. 
16

Figure 4 through Figure 6 below were developed and provided to the participating insulation 

companies as typical wall sections with the thermal and vapor management properties meeting 

the IECC 2012 and IRC 2012 requirements, respectively. These figures were intended to be used 

as a base for developing variations on their current product offerings aimed at performing 

multiple functions, some of which were specific to the needs of factory homebuilders.

Figure 4 is a typical wall section of a stud wall with exterior insulation meeting the thermal 

requirements of IECC 2012 climate zone 5, based on the following heat flow targets:

• Prescriptive: R-20 or R-13+5 (wall insulation R-value)

or,

• Whole wall performance: 0.057 (wall U-factor).

Figure 4. Stud wall with exterior insulation, Design 1 (climate zone 5)

Figure 5 and Figure 6 are typical wall sections of stud walls with exterior insulation meeting the 

thermal requirements of IECC 2012 climate zones 6, 7, and 8, based on the following thermal 

resistance targets:

• Prescriptive: R-20+5 or R-13+10 (wall insulation R-value)

• Whole wall performance: 0.048 (wall U-factor).

Figure 5 is a stud wall with 2 in. × 4 in. framing, R-13 cavity insulation and R-10 exterior 

insulation. Figure 6 is a similar wall section but with 2 in. × 6 in. framing and R-5 exterior 

insulation. Cavity insulation is R-20.
17 

Figure 5. Stud wall with exterior insulation, 

Design 2 (climate zones 6, 7, and 8)

Figure 6. Stud wall with exterior insulation, 

Design 3 (climate zones 6, 7, and 8)

4.2 Design Development

This section describes the various advanced wall solutions developed based on superior 

insulation products from the participating insulation manufacturers integrated with the provided 

wall performance specifications.

4.2.1 AFM Corporation

4.2.1.1 Company Background

AFM Corporation is the manufacturer of Foam-Control expanded polystyrene (EPS) and RControl branded SIPs. Foam-Control and R-Control products are available through a network of 

AFM licensed manufacturing facilities.

4.2.1.2 Concept Overview 

AFM Corporation proposed advanced wall designs for the factory built housing industry 

incorporating the use of Foam-Control Nailbrace. The proposed design concept is as follows: 

• Concept A: Stud walls with Foam-Control Nailbrace with integrated structural sheathing 

and weather resistant barrier (WRB). 

The following sketches show the Foam-Control Nailbrace wall concepts designed for as per the 

specifications for Designs 1 and 2 (see Table 1) in climates zones 5, 6, 7, and 8. Similar designs 

were also developed in response to the requirements for Design 3. 
18

Figure 7. Foam-Control Nailbrace Concept A, 

Design 1 (climate zone 5)

Figure 8. Foam-Control Nailbrace Concept A, 

Design 2 (climate zones 6, 7, and 8)

4.2.1.3 Design and Materials

Foam-Control Nailbrace is a continuous insulation (CI) 

board applied to the exterior side of framed walls. This 

product incorporates EPS insulation laminated onto a 

structural engineered wood sheathing backer. The design 

incorporates a let-in strip for fastening the siding. This 

design makes the Foam-Control Nailbrace lighter and 

easier to handle in a production setting.

The let-in strip in the Foam-Control Nailbrace panel is 

designed for easy attachment of the siding. Specialty 

fasteners are required for bracing and to protect against 

fastener bending and pull-out/pull-through.

4.2.1.3.1 Strengths and Limitations

Foam-Control Nailbrace potentially provides the following 

strengths and limitations:

Strengths

• Braces framed walls and provides structural 

support

• Provides attachment for exterior cladding

• Pre-installed WRB and air barrier.

Figure 9. Foam-Control Nailbrace 

with let-in bracing (without WRB)

(Image credit: AFM Corporation, 

used with permission)

Figure 10. Foam-Control Nailbrace - top 

view (without WRB)

(Image credit: AFM Corporation, 

used with permission)
19

Limitations, restrictions on use, general technical challenges

• Alignment of let-in bracing with fastening may be a challenge.

• Cost of composite panel fabrication is likely to be higher than standard sheathing.

4.2.1.3.2 Thermal Properties

Foam-Control Nailbrace incorporates EPS foam insulation with a thermal resistance of R-4/in.

4.2.1.3.3 Available Sizes and Weights

Foam-Control Nailbrace is available in the following sizes and weights (Table 2).

Table 2. Foam-Control Nailbrace—Sizes and Weights

(Source: Tobin 2012)

R-Value Thickness*

(in.)

Panel Size

(ft)

Weight

(lb/ft2)

R-5 1.625

4 × 8

4 × 9

4 × 10

4 × 12

8 × 24 (custom-made)

1.5

R-10 2.875

4 × 8

4 × 9

4 × 10

4 × 12

8 × 24 (custom-made)

1.6

*

Foam-Control Nailbrace can be manufactured with NEOPOR providing a higher R-value (R-4.8)/in. NEOPOR is a 

registered trademark of BASF.

4.2.1.3.4 Structural Performance

The backer in the Foam-Control Nailbrace panel is designed to provide structural strength. 

Testing is required to establish the structural performance of this composite board. The following

structural tests may need to be conducted for code compliance:

• ASTM E72 or ASTM E564—shear-wall/racking

• Fastener pull-out

• AF&PA NDS–05 (wood)

• AISI S100-2007 (steel)

• ICC-ES AC 269—CI used as bracing.

Performance and structural tests conducted would be used to include Foam-Control Nailbrace in 

AFM Corporation’s ICC ESR–1006.
20

4.2.1.3.5 Weather Resistive Properties

Foam-Control Nailbrace can be manufactured with a factory applied WRB. In this case, edges 

are required to be taped. Testing is required to establish the WRB and air barrier properties of 

Nailbrace. The following tests may need to be conducted for code compliance:

• ICC-ES AC 71—foam as a WRB

• ASTM E2357—air infiltration

• ASTM E1677—air barrier performance.

4.2.1.3.6 Vapor Management Properties

Foam-Control Nailbrace classifies as a Class III VR.

4.2.2 BASF Corporation

4.2.2.1 Company Background

BASF is a chemical company that provides raw materials to fabricators and intermediaries that 

produce construction-ready products. In the case of NEOPOR—a BASF-produced and patented 

raw material—NEOPOR rigid thermal insulation is produced in the United States and Canada 

under a brand marketing agreement by customers of BASF Corporation and BASF Canada, 

respectively, who convert NEOPOR (the raw material) to NEOPOR foam (rigid thermal 

insulation).

4.2.2.2 Concept Overview

BASF proposed four advanced wall designs incorporating insulation made from its NEOPOR

(BASF 2011) rigid thermal insulation product. The four proposed design concepts are as follows:

• Concept A: Stud walls with NEOPOR rigid thermal insulation

• Concept B: Stud walls with oriented strand board (OSB) laminated to NEOPOR rigid 

thermal insulation

• Concept C: Stud walls with poly-faced NEOPOR rigid thermal insulation

• Concept D: Stud walls with foil-faced NEOPOR rigid thermal insulation.

Figure 11 through Figure 14 show wall sections of the four NEOPOR-based concepts in 

accordance with wall Designs 1 and 2 (see Table 1). Similar designs were also developed in 

response to specifications for Design 3.
21

Figure 11. NEOPOR Concept A, Design 1

(climate zone 5)

Figure 12. NEOPOR Concept A, Design 2

(climate zones 6, 7, and 8)

Figure 13. NEOPOR Concept B, Design 1

(climate zone 5)

Figure 14. NEOPOR Concept B, Design 2 

(climate zones 6, 7, and 8)
22

Figure 15. NEOPOR Concept C, Design 1

(climate zone 5)

Figure 16. NEOPOR Concept C, Design 2 

(climate zones 6, 7, and 8)

Figure 17. NEOPOR Concept D, Design 1

(climate zone 5)

Figure 18. NEOPOR Concept D, Design 2

(climate zones 6, 7, and 8)

4.2.2.3 Design and Materials

BASF NEOPOR is a unique and patented material used, in its final form, as “rigid thermal 

insulation” in the construction industry as thermal insulation. This material attributes a 

distinctive silver-gray color to graphite contained within a polystyrene-based polymer matrix. 

BASF incorporates high-purity graphite into the polymer matrix. The graphite particles both 

reflect and absorb radiant energy, thereby increasing the materials insulation capacity, or R-
23

value, while retaining all of the performance benefits inherently found in standard white EPS. 

NEOPOR rigid thermal insulation can be block molded and wire-cut to form both simple and 

complex profiles using standard industry equipment and processes.

The physical properties of NEOPOR are outlined in Table 3.

Table 3. NEOPOR—Physical Properties

(Source: BASF 2012, used with permission)

4.2.2.3.1 Strengths and Limitations

The strengths and limitations of NEOPOR insulation board are summarized below.

Strengths

• Lightweight

• Easy to cut, shape, install

• GreenGuard Gold certified for Indoor Air Quality by Underwriters Laboratories 

Environment

• Long-term stable R-value of 4.5–4.6/in., depending upon density

• Dimensionally stable 

• Expansion agent has zero ozone depletion potential

• Expansion agent has low global warming potential.
24

Limitations, restrictions on use, general technical challenges

• NEOPOR boards are nonstructural.

4.2.2.3.2 Thermal Properties

NEOPOR has an average R-value of 4.8/in. over the temperature range of 23°–75°F and density 

range of 1.15 pcf (ASTM Type VIII) to 1.80 pcf (ASTM Type IX). The R-value increases as the 

temperature decreases. The thermal resistance (R-value) properties of NEOPOR are outlined in 

Table 4.

Table 4. R-Value of NEOPOR Rigid Thermal Insulation

(Source: BASF 2013, used with permission)

NEOPOR 5300 PLUS is a raw material used to produce rigid thermal insulation made of 

NEOPOR that has the highest R-value of any NEOPOR rigid thermal insulation. Wall systems 

designed with the R-values for NEOPOR 5300 PLUS should specify “NEOPOR 5300 PLUS” on 

all system and material specifications.

NEOPOR F 5300 and NEOPOR F 5300 PLUS is a raw material used to produce rigid thermal 

insulation and uses a polymeric flame retardant instead of HBCD. R-values of NEOPOR at 

various temperatures and material densities are shown in Figure 19.
25

Figure 19. NEOPOR R-value at 75°F and 40°F

(Source: BASF 2013, used with permission)

4.2.2.3.3 Available Sizes and Weights

NEOPOR boards are commonly available in the following sizes and weights. However, 

NEOPOR is adaptable and can be specified in any thickness and density to achieve specific Rvalue performance targets.

Table 5. NEOPOR—Sizes and Weights

(Source: Fox 2012)

R-Value Thickness

(in.)

Panel Size

(ft)

Weight

(lb/panel)

R-5 1.125 4 × 8 4

R-10 2.25 4 × 8 N/A

OSB-laminated R-5 1.5 4 × 8 54

OSB-laminated R-10 2.625 4 × 8 N/A
26

4.2.2.3.4 Structural Performance

Concepts A, C, and D incorporate NEOPOR boards that are nonstructural. The OSB-laminated 

NEOPOR board in Concept B provides structural strength. Testing is required to establish the 

shear resistance of this composite board.

4.2.2.3.5 Weather Resistive Properties

Concepts A and B call for the use of a separate WRB to provide water and air resistance13 to the 

wall system. The OSB-laminated NEOPOR board has the option of a factory-applied WRB 

(poly- or foil-faced) to act as a water resistive and an air infiltration barrier. Additional testing is 

required to confirm its performance.

4.2.2.3.6 Vapor Management Properties

Depending on density, 1 in. thick NEOPOR has a perm rating of 1.5–3.5 (ng/Pa·s·m2). The 

classification of the various NEOPOR products based on their permeance is as follows:

• Unfaced foam: Class III VR

• OSB-laminated panel: Class III VR

• Poly- and foil-faced foam: Class II VR.

4.2.3 The Dow Chemical Company

4.2.3.1 Company Background

Dow is a global business with a broad range of insulation and other building products for the 

construction industry.

4.2.3.2 Concept Overview

Dow proposed advanced wall designs incorporating its Styrofoam brand extruded polystyrene

(XPS) insulation board. Figure 20 is a wall section with Styrofoam XPS designed to meet the 

2012 IECC prescriptive code requirements for climate zone 5. Figure 21 shows the wall design 

meeting code requirements for climate zones 6, 7, and 8 with R-13 in the cavity and R-10 

exterior insulation. A similar design was also developed for climates zones 6, 7, and 8 with R-21 

in the cavity and R-5 exterior insulation.

 13 The OSB or NEOPOR layers can provide air resistance to the wall system if properly taped and sealed or an 

additional barrier is required.
27

Figure 20. Stud wall with Styrofoam, 

Design 1 (climate zone 5) Figure 21. Stud wall with Styrofoam, 

Design 2 (climate zones 6, 7, and 8)

4.2.3.3 Design and Materials

Styrofoam brand is an XPS foam board used for exterior wall sheathing.

4.2.3.3.1 Strengths and Limitations

The strengths and limitations of Styrofoam brand XPS board are summarized below.

Strengths

• Lightweight

• Higher per inch R-value than EPS

• Easy to cut, shape, install

• Can serve as a WRB.

Limitations, restrictions on use, general technical challenges

• Styrofoam boards are nonstructural.

4.2.3.3.2 Thermal Properties

Styrofoam brand XPS foam insulation has a thermal resistance of ~R-5/in.

4.2.3.3.3 Available Sizes and Weights

Styrofoam boards are available in the following sizes and weights (Table 6).
28

Table 6. Styrofoam—Sizes and Weights

(Source: Mallon and Lieburn 2012)

R-Value Thickness 

(in.)

Panel Size

(ft)

Weight 

(lb/panel)

R-5 1 4 × 8

4 × 9 N/A

R-10 2 4 × 8

4 × 9 N/A

4.2.3.3.4 Structural Performance

Styrofoam brand foam board is nonstructural.

4.2.3.3.5 Weather Resistive Properties

Styrofoam brand foam board is ICC-ES code approved WRB, with tape, sill pans, flashings, 

spray foam, and foam sealants. It also passes the ASTM E331 wall assembly test for determining 

resistance to water penetration.

4.2.3.3.6 Vapor Management Properties

R-5 Styrofoam brand foam board is a Class III VR, while R-10 board is classified as Class II.

4.2.4 Johns Manville Corporation

4.2.4.1 Company Background

Johns Manville (JM) is a manufacturer and marketer of building insulation, commercial roofing, 

roof insulation, and specialty products for commercial, industrial, and residential applications. 

JM’s product offerings include formaldehyde-free fiberglass, spray polyurethane foam, 

polyisocyanurate foam board, and mineral fiber building insulations, commercial roofing 

membranes and roof insulations, filtration media, and mats and reinforcements.

4.2.4.2 Concept Overview

JM proposed the following three wall designs incorporating polyisocyanurate insulation.

• Concept A: Stud walls with ValuTherm sheathing

• Concept B: Stud walls with AP foil-faced sheathing

• Concept C: Stud walls with structural insulated sheathing (SIS).

Figure 22 through Figure 24 show typical wall sections based on JM’s three proposed concepts 

designed for climate zones 5, 6, 7, and 8.
29

Figure 22. ValuTherm Concept A

(climate zones 5, 6, 7, and 8)

Figure 23. AP foil-faced sheathing Concept B 

(climate zones 5, 6, 7, and 8)

Figure 24. SIS sheathing Concept C (climate zones 5, 6, 7, and 8)

4.2.4.3 Design and Materials

Concept A has a polyisocyanurate foam core with fiberglass reinforced paper facers. Concept B 

has a polyisocyanurate foam core with bi-laminate foil facers. Concept C has a polyisocyanurate 

foam core with a foil facer on one side and a reinforced/structural facer on the other. The 

physical properties of the polyisocyanurate insulation products in the three proposed concepts are 

outlined in Table 7.
30

Table 7. JM Products—Physical Properties

(Sources: JM 2009, 2013a)

Property ValuTherm AP Foil-Faced Sheathing Structural Insulated 

Sheathing*

R-Value and 

Thickness

R-5 @ 0.89 in.

R-10 @ 1.78 in.

R-5 @ 0.77 in.

R-10 @ 1.55 in.

R-5 @ 0.77 in.

R-10 @ 1.55 in.

Compressive 

Strength 16 psi 16 psi 20 psi

Dimensional 

Stability ≤ ± 2% ≤ ± 0.2% (length and width)

< ± 2% (thickness) ≤ ± 2%

Water Vapor 

Permeance

1.0 perm-in. 

(Class II VR)

0.05 perm-in. 

(Class I VR)

0.05 perm-in. 

(Class I VR)

Water 

Absorption ≤ 1.5% 0.3% ≤ 1%

Flame Spread/ 

Smoke 

Developed**

N/A ≤ 25 / 450 ≤ 25 / 450

Complies With

ASTM C1289-

12, Type II, 

Class 1, Grade 2

ASTM C1289-12, Type I, 

Class 1, Grade 1

ICC-ESR 3398

ASTM C1289-12, 

Type I, Class 1

AC 269/269.2

* The SIS sheathing product is currently under development and its properties are subject to development and/or 

testing. Values provided in this table are estimates.

**Foam core, 4 in. thickness

4.2.4.3.1 Strengths and Limitations

The strengths of the polyisocyanurate foam board and limitations of the products for the

proposed concepts are listed below:

Strengths

• R-value of the foam is the highest of the products considered in this research phase

• Lightweight

• Easily cut by razor, utility knife, band saw, hot wire, etc.

• Dimensional stability < 0.3%,

14 Foam core flame spread/smoke developed indices low 

compared to standard products

• Concept B product can be used as an air barrier and drainage plane

• Concept C has a structural facer eliminating the need for additional structural support

 14 Babineau, F. (November, 2012). Johns Manville Insulating Sheathing Concepts. (PowerPoint slides). Presented at 

the Building America Expert Meeting, Harrisburg, PA.
31

Limitations, restrictions on use, general technical challenges

Concept A

• Requires a separate, exterior water barrier

• No fire certification on the foam board

• No tested structural benefit from ValuTherm.

Concept B

• No tested structural benefit from the AP foil-faced sheathing.

Concept C

• The SIS sheathing product is under development (not commercially available yet). 

Additional tests and code approval are pending.

4.2.4.3.2 Thermal Properties

JM’s proposed wall concepts incorporate closed cell polyisocyanurate insulation with a thermal 

resistance of ~R-6.5/in.

4.2.4.3.3 Available Sizes and Weights

Table 8 and Table 9 provide information on available sizes and weights of ValuTherm and AP 

foil-faced insulation. Since the SIS sheathing product is under development, information on sizes 

and weights is not available.

Table 8. ValuTherm—Sizes and Weights

(Source: JM 2013b)

R-Value Thickness

(in.)

Panel size

(ft) Weight

R-5 N/A 4 × 4 N/A

R-10 N/A 4 × 8 N/A

Table 9. AP Foil-Faced Insulation—Sizes and Weights

(Source: JM 2013c)

R-Value Thickness 

(in.)

Panel size

(ft)

Weight 

(lb/panel)

R-5 N/A 4 × 8

4 × 9

4.1

4.6

R-10 N/A 4 × 8

4 × 9

8.3

9.3
32

4.2.4.3.4 Structural Performance

For concepts A and B, the polyisocyanurate foam board is nonstructural. Concept C, SIS

sheathing is manufactured with a structural facer and, pursuant to test verification, eliminates the 

need for additional shear resistance.

4.2.4.3.5 Weather Resistive Properties

Concept A requires the use of a separate, exterior WRB. In concepts B and C, the facers function 

as water resistant and air infiltration barriers when taped and sealed. Table 10 specifies the 

weather resistive properties of AP foil-faced insulation.

Table 10. AP Foil-Faced Insulation—Weather Resistive Properties

(Source: JM 2013c)

Function Criteria and Results Details

Water Drainage 

(WRB)*

AC 71: No visible leakage after 

2-h test Exova report 12-06-M0306-2

Water Drainage (WRB)

AC 71 weathering: No visible 

leakage after UV light exposure 

and accelerated aging

Exova report pending

Air Barrier ASTM E2357: 0.00426 L/sm2

(~1% of allowable leakage) Exova report 12-06-M0306-1

Lateral Wind Loads ASTM E1233: resisted -1880 Pa Exova report pending

* WRB, air leakage, and wind loading tested with 3M 8067 flashing tape, Tremco Spectrem I sealant, and 2 in.

fastener plates

4.2.4.3.6 Vapor Management Properties

All three proposed products have a perm rating of 1.0 or lower, making them Class I and II VRs.

4.2.5 Saint-Gobain/CertainTeed

4.2.5.1 Company Background

CertainTeed Corporation is a manufacturer of building materials including roofing, vinyl and 

fiber cement siding, trim, fence, railing, decking, foundations, insulation, gypsum, ceilings, and 

pipe products. CertainTeed is a subsidiary of Saint-Gobain.

4.2.5.2 Concept Overview

CertainTeed proposed an advanced wall solution incorporating their brand product CertaPro 

fiberglass insulative sheathing with an optional WRB facing.

Figure 25 and Figure 26 show typical wall sections proposed for climate zones 5, 6, 7, and 8 in 

response to the specifications in Designs 1 and 2, respectively. A similar design was developed 

for climate zones 6, 7, and 8 meeting Design 3 requirements. 
33

Figure 25. Stud wall with faced CertaPro, Design 1 (climate zone 5)

Figure 26. Stud wall with faced CertaPro, Design 2 (climate zones 6, 7 and 8)

4.2.5.3 Design and Materials

The physical properties of unfaced CertaPro fiberglass insulation are outlined in Table 11 below.
34

Table 11. CertaPro—Physical Properties

(Source: CertainTeed 2010)

Property Value

Density (lb/ft3) 4.0

Thermal Resistance (R/in.) 4.3

Water Vapor Absorption (by weight) 2.0%

Compressive Strength (psi @ 10% def) 0.75

Recycled Content Approx. 60%

Flame Spread Index 25

Smoke Developed Index 50

Water Vapor Permeance (perm) >10

Noise Reduction Coefficient 0.8 (1-3/16 in. thick) 1.0 (23⁄8 in. thick)

4.2.5.3.1 Strengths and Limitations

The strengths and limitations of CertaPro fiberglass insulation are summarized below.

Strengths

• Higher R-value per inch than standard EPS

• Provides high sound absorption

• Contains approximately 60% recycled content

• Offered in a variety of stiffness properties from flexible to rigid and all can be easily 

cut, handled, fabricated, and installed

• Resists mold and mildew and will not rot or deteriorate

• Has superior fire performance (25/50).

Limitations, restrictions on use, general technical challenges

• CertaPro boards are nonstructural.

4.2.5.3.2 Thermal Properties

CertaPro fiberglass insulation board has a thermal resistance of R-4.4/in.

4.2.5.3.3 Available Sizes and Weights

CertaPro insulation is available in the following sizes and weights.
35

Table 12. CertaPro—Sizes and Weights

(Source: CertainTeed 2010)

R-Value Thickness

(in.)

Panel Size 

(ft)

Weight

(lb/ft2)

R-5 1-3/16 4 × 8 0.39

R-10 23⁄8 4 × 8 0.78

4.2.5.3.4 Structural Performance

CertaPro fiberglass insulation board is nonstructural.

4.2.5.3.5 Weather Resistive Properties

CertaPro insulation is available with an optional WRB facing. The WRB facing with taped 

seams qualifies as a water resistive and air barrier.

4.2.5.3.6 Vapor Management Properties

The WRB facing on CertaPro insulation classifies as a Class III VR.

4.3 Production Analysis

This section addresses production impact of the designs. The team conducted an independent 

assessment of the process by which the options would be integrated into the manufacturing 

fabric, considering the following factors:

• Safety: risk of injury when performing the operations, using the equipment and handling 

the material

• Quality: likelihood of scrap, rework, delays in the factory and, worst of all, service calls

• Labor: added work content for sheathing activity

• Flow: increased risk of line disruptions, added workstations and subsequent activities 

pushed down-line, etc.

The impact of the proposed options on standard production process is graphically presented 

below. The steps involved in standard wall production are listed to the left. An “X” indicates that 

the product has a measurable impact on production. The relative size of the impact is suggested 

by color coding. The colors are in order of greatest to least impact: red, orange, and yellow.
36

Table 13. Impact Summary—Work Content

AFM BASF Dow JM SG OC

Production Issues Nailboard NEOPOR Styrofoam AP Foil S. I. S. CertaPro Foamular

Separate OSB 

Installation X X X X

Separate Batten 

Boards/Furring 

Strips

X* X* X

Screws Used To 

Install Insulation X X

Fasteners for R-5 

Insulation Not 

Collated

Fasteners for R-10 

Insulation Not 

Collated

X X X X X X X

Cladding Attached 

To Frame Through 

Insulation

X * * X

Fasteners for 

Cladding Not 

Collated, R-5 Panel

* *

Fasteners for 

Cladding Not 

Collated, R-10 Panel

X X

* These products require furring strips to attach foam/cladding (except vinyl attached to R-5); vinyl is attached 

through R-5 using 2.5-in. noncollated nails.

The effects of increased work content compared to standard wall production process are 

summarized below:

• Sheathing labor cost is twice as much for nonstructural concepts

• Nonstructural concepts requiring furring and noncollated fasteners through 2 in. or 

thicker exterior insulation layers show a threefold increase in sheathing labor cost

• There is an increased risk of flow disruptions

• Sheathing workstations would require one additional station for nonstructural concepts

• Two additional workstations would be needed for nonstructural concepts requiring furring 

and noncollated fasteners.

4.4 Thermal and Cost Benefit Analysis

Typically, simulation tools such as BEopt are used to help differentiate among alternative 

measures for reducing energy use. Measures are assigned costs, their energy savings are 
37

estimated and then are ranked in terms of cost effectiveness. This approach allows different types 

of measures (impacting different end uses, with varying impacts on energy use and with different 

costs) to be readily compared and combined into cost-optimized whole building solutions. 

However, the team was operating within a different context for cost optimization where the end 

result is fixed (in this case, wall R-value to be achieved using insulative sheathing). The 

questions revert to: 

• What is the least cost way to reach the specified R-value?

• What should the target cost be to achieve a designated economic return, such as payback 

or return on investment?

The first question is readily answered by comparing costs of alternatives: in this case, more than 

50 options for using R-5 and R-10 insulative sheathing developed in partnership with six original 

equipment manufacturer (OEM) insulation suppliers. The task is simply to determine which 

option(s) is the least costly; material, labor, and related costs considered. The second question—

what should the cost be to satisfy preset financial criteria—is more salient. Different parties may 

have divergent views on what qualifies as cost effective. To begin to place bounds on the answer, 

an analysis was conducted for representative locations in IECC regions 5, 6, and 7 (all are in 

zone 3 of the HUD thermal standards). Energy savings was projected using BEopt and maximum 

measure costs were calculated that satisfy three economic metrics: simple pay back (7-year time 

horizon); return on investment (target 10%); and net zero cash flow (first year). The results are 

shown on Table 14.

Table 14. Allowable Cost of Insulative Sheathing To Qualify as Cost Effective

Location IECC 

Region

Energy 

Savings 

($/ft2/yr)

Maximum Allowable Cost ($/ft2)

Simple 

Payback 

(7-yr)

Return on 

Investment 

(10%)

Net Zero 

Cash Flow 

(year 1)

Lancaster, Pennsylvania 5 $0.114 $0.80 $1.14 $1.53

Great Falls, Montana 6 $0.157 $1.10 $1.57 $2.11

International Falls, 

Minnesota 7 $0.189 $1.32 $1.89 $2.54

For these three methods of measuring cost-benefit, the threshold maximum cost when adding 

insulative sheathing is $0.80–$2.54 (a huge range reflecting, in part, climate variations, energy 

costs, and differences in requirements by climate region, among other factors). To be deemed 

cost effective, the incremental cost of the measure will need to be equal to or below these values; 

that is, if the cost of the measure is higher than this range it can be broadly deemed not to be cost

effective. (The three methods for conducting cost-benefit analysis are intended to be illustrative, 

not exhaustive. For example, using a life cycle cost optimization criterion would likely result in 

different [higher?] allowable measure costs, as would modifying the assumptions used with any 
38

of the economic models.) The bottom line for the team is finding insulative sheathing solutions 

that will have a net cost to the consumer of less than $2.00/ft2 for IECC region 5 designs and less 

than $3.00/ft2 for homes in regions 6 and 7.

At this stage in the analysis the actual anticipated costs of the proposed measures (materials, 

inventorying, added labor to install, amortization of special equipment, etc.) are not sufficiently 

detailed to be reliable. However, the allowable cost approach provides a valuable reference point 

for the team going forward. As noted earlier, these measures are likely to be mandated by code in 

the near future; that is, cost-benefit analysis results will be instructive but will not impact the

decision by factory builders to construct walls with insulative sheathing.

The wall measures under investigation are part of a wider effort to move factory built homes to 

levels of energy use that are 50% less than current construction. The ARIES partnership with the 

industry is focusing attention on each envelope component sequentially (starting with walls) with 

the goal of developing and transitioning to market viability component designs predicated on 

cutting energy use by half. Table 15 suggests the extent to which the insulative sheathing 

solutions will impact energy use.

Table 15. Comparison of U-Values

Description Base 

Case

Design 1

IECC Region 5

Design 2

IECC Regions 6 and 7

Effective R-Value 

(Insulation Only) 11.4 17.0

(R-5 insulative sheathing)

22.2

(R-10 insulative sheathing)

Component U-Value

(per BEopt) 0.877 0.059 0.045

Change in U-Value

(%) – 32% 49%

Compared with current typical construction, future changes in the building code alone are 

expected to reduce wall-related thermal transmission energy use by about 32% (IECC region 5) 

and 49% (IECC regions 6 and 7), respectively. (The HUD standards (base case) currently have a 

single requirement for areas covered by IECC regions 5, 6, 7, and 8.) Moving practice to the R10 insulative sheathing solution for homes in all of these regions (the 49% solution) is feasible 

provided the research can yield designs using R-10 insulative sheathing for a net cost of about 

$3.00/ft2

, as discussed above. Achieving this cost target is a major goal of the next research 

phase.

4.5 Moisture Analysis

With the emphasis on providing greater insulation value on the exterior of the wall framing, the 

team considered how altering the thermal balance of the wall would change the dynamics of

moisture flow and, consequently, the need for and location of a Class I or II VR. Common

practice in the northern, mainly heating-dominated climates is to place materials with low perm 

ratings on the interior of the wall. During the heating season, water vapor produced in the home 

is kept from entering the wall cavity where it might condense. However, many in the building 
39

science community contend that using a Class III VR on the interior is appropriate when 

applying insulative sheathing to the exterior of the wall. This view is codified in Section 

R702.7.1 of the 2012 IRC.

15, 16

In setting desired wall properties for the design development work, the team provided for three 

ways to approach moisture control: (1) using a Class I or II VR on the exterior of the wall; (2)

applying a Class I or II material on the interior of the wall (as traditionally built); or (3) having 

no Class I or II VR anywhere in the wall. Preliminary WUFI analysis was conducted on several 

of the designs. Two cases illustrate the results. 

Figure 27 shows a cross section of a wall with 2 in. of XPS insulation (blue bar). The wall, from 

exterior to interior, has exterior vinyl siding, XPS, OSB, framing with batt insulation, and 

gypsum board finished with two coats of latex paint. The insulation has a Class II VR rating; all 

other materials are rated Class III or are vapor permeable. The graph below charts the relative 

humidity (RH) and temperature at the inside surface of the OSB, the place in the wall 

experiencing the highest RH readings. As can be seen, RH, an indicator of the propensity of the 

wall to experience conditions that might be conducive to mold growth and condensation, peaks 

in the shoulder months. However, the conditions rarely exceed 95% RH for sustained periods,

suggesting that this wall is unlikely to experience moisture-related failures.

WUFI results for the 6 in. frame wall with R-5 insulative sheathing show a similar pattern with 

lower RH values (see Figure 28). This wall uses the same materials, although a Class II VR is 

applied between the framing and gypsum board. It is likely that removing the VR would elevate 

RH levels but not to a degree that would cause concern. This configuration will be explored 

further in subsequent phases of the research.

 15 During a project Expert Meeting, Joe Lstiburek of Building Science Corporation discussed the testing and 

research conducted to support this approach and the genesis of the IRC requirement.

16 It should be noted that the moisture analysis considers vapor flow and ignores air transported moisture. Airflow 

and air leakage typically are much more significant to moisture transport than vapor diffusion.
40

Figure 27. WUFI results for wall with R-10 (2 in. XPS) insulation in International Falls
41

Figure 28. WUFI results for wall with R-5 (1 in. XPS) insulation in International Falls

4.6 Prototyping and Testing

An Expert Meeting was held on November 29, 2012 where the insulation companies presented 

the wall design concepts to an expert panel consisting of representatives of the factory built 

housing industry, the ARIES technical team, selected product supplier representatives, and other 

stakeholders. Subsequent to this meeting, the ARIES team and industry committee convened to 

discuss and debate the relative merits of the proposed wall options. The group identified five 

solutions to move to the next step in this research phase: prototyping and testing.

The group agreed that the first round of prototyping and testing would focus on the following 

two options:

• Stud walls with Styrofoam (in collaboration with Dow Corporation)

• Stud walls with Foam-Control Nailbrace (in collaboration with AFM Corporation).
42

The insulation type for both products is polystyrene; EPS (Foam-Control Nailbrace) and XPS 

(Styrofoam) in two thicknesses each, to achieve R-5 and R-10.

The two-day meeting consisted of the following evaluations:

• Racking test demonstrating structural compliance with ASTM E72-80 or ASTM E564 

required for compliance under the HUD standards.

• Wall panel mockup for assessing fabrication sequence, building details, and related issues.

• Window construction assessment, particularly with regard to structural support of the 

window when perched over the exterior insulation.

4.6.1 Location and Participants

Prototyping and testing of the selected solutions was conducted on February 6 and 7, 2013 at a 

participating partner manufacturing plant—Fleetwood Homes, Inc.— in Riverside, California. 

Fleetwood Homes is a subsidiary of Cavco Industries.

The meeting was attended by the project steering committee, the insulation manufacturers 

involved in the design development of the selected wall options, and the ARIES technical team.

4.6.2 Racking Tests

Racking tests were conducted on the Dow and AFM products in a few different configurations.

The purpose of the racking tests was to develop a ballpark estimate of racking strength, a 

preliminary figure to guide future analysis and design direction. A single test was performed for 

each wall following the ASTM E564 protocol with regard to load application and load cycling

(typically the testing protocol involves the averaging of results from three samples).

Only walls with R-5 were tested, the most likely insulation level to be used in the short term. For 

the testing of the wall with Dow Styrofoam, the team speculated that the siding and gypsum 

board might impact the ultimate shear load. Four tests were conducted, two with each siding 

material representative of the typical products used by the factory building industry that were 

expected to provide some racking strength (vinyl was not tested). The siding materials were each 

tested with and without interior gypsum board.

17 Table 16 lists the variations of wall type 

combinations with Styrofoam that were subject to the ASTM E72-80/E564 racking test.18 See 

Appendices A and B for details on the tests and equipment and material needs. 

 17 Testing was done on wall assemblies without gypsum board to compare results with assemblies that included 

gypsum board. As noted earlier, gypsum board with the proper adhesive may provide sufficient shear resistance but 

only in certain areas. Additional shear resistance may be needed in higher wind zones.

18 The tests followed the procedures described in the ASTM protocol except only a single sample of each wall was 

tested. The full qualifying protocol requires testing three samples of each wall and averaging the results.
43

Table 16. Racking Tests—Stud Walls With Styrofoam

Case No. R-Value 

(thickness) Siding Gypsum Board Present

Ultimate Load 

(lb)

RD1 (a) R-5 (1 in.) LP SmartSide Yes 6,701

RD1 (b) R-5 (1 in.) LP SmartSide No 5,842

RD2 (a) R-5 (1 in.) Cempanel Yes 4,523

RD2 (b) R-5 (1 in.) Cempanel No 6,200

Table 17 lists the racking test iterations for wall options based on the “stud walls with FoamControl Nailbrace” design.

Table 17. Racking Tests—Stud Walls With Foam-Control Nailbrace

Case No. R-Value 

(thickness) Siding Gypsum Board Present

Ultimate Load 

(lb)

RA1 (a) R-5 (15⁄8 in.) LP SmartSide Yes 7,154

RA1 (b) R-5 (15⁄8 in.) LP SmartSide No Excessive 

deflection

4.6.3 Process Mockup Evaluation and Observation

The purpose of the partial wall mockups was to consider issues that will arise in a plant setting 

when the materials, associated with the Dow and AFM design concepts move into production. 

Again, this was a limited evaluation intended to reveal general issues of material assembly and 

production friendliness. The mockups were intended to expose major stumbling blocks to be 

addressed by future research. The design of the mockups followed from discussions with the 

industry panel and reflected, in part, their preferences with regard to combinations of materials. 

Table 18 lists the different wall type combinations with Styrofoam that were mocked up.

Table 18. Process Mockups—Stud Walls With Styrofoam

Case No. R-Value 

(thickness)

Separate Structural 

Sheathing Present Siding Window Framing Detail No.*

MD1 R-5 (1 in.) No LP SmartSide 1

MD2 R-5 (1 in.) No LP SmartSide 3

MD3 R-5 (1 in.) Yes (OSB) Cempanel 2

MD4 R-10 (2 in.) No Cempanel 1

*See Section 4.6.4 for a description of the window framing details.
44

Table 19 lists the process mockup iterations for wall options based on the “stud walls with FoamControl Nailbrace” design.

Table 19. Process Mockups—Stud Walls With Foam-Control Nailbrace

Case No. R-Value 

(thickness)

Separate Structural 

Sheathing Present Siding Window Framing Detail No.*

MA1 R-5 (15⁄8 in.) No LP SmartSide 1

MA2 R-5 (15⁄8 in.) No Vinyl 3

MA3 R-5 (15⁄8 in.) No Vinyl 2

*See Section 4.6.4 for a description of the window framing details.

4.6.4 Window Construction Assessment

One of the major issues of concern is the durability of the window attachment to the structural 

frame when the window partially or entirely sits over the exterior insulation. The group agreed to 

consider three methods of detailing the window frame for comparative analysis in Riverside: 

having the window sit on the foam insulation and secured to the frame with nails, creating a buck 

lumber frame around the window, and inserting a thin profile rail or clip that attaches to the 

frame and supports the window. The three options are shown in Figure 29 through Figure 31

below.

Figure 29 (Detail 1) shows a simple installation option where the window frame bearing rests on 

the foam.

19

Figure 29. Detail 1—Window frame bearing on foam

Figure 30 is a wall opening detail with a protruding frame designed to provide the window with 

solid wood bearing. This design also includes a foam spacer that reduces thermal bridging.

 19 Placing the flange over the siding is standard industry practice. 
45

Figure 30. Detail 2—Window framing with buck lumber

Figure 31 shows detail of a window frame installation option with a metal L-section providing a 

rigid surface to support the window.

Figure 31. Detail 3—Window framing with metal L-section
46

5 Discussion

5.1 Stud Walls With Styrofoam

In general, the use of Dow Styrofoam brand XPS insulation board and related products offered a 

solution that is fairly well-resolved with regard to construction detailing but requires further 

development for factory use. For the most part, the tongue and groove material fit together with 

relative ease, presenting no apparent thermal breaks—realizing the primary goal of substantially 

increasing the thermal integrity of the wall. The relative high density and compression strength 

of the foam may be sufficient to allow the window to bear partially or entirely on the foam,

enabling the use of fairly simple windows and door framing details. Visually, the foam coverage 

gave the impression of a CI layer that is durable, virtually eliminates thermal bridging, and can 

be installed in the plant with little training. Application of tape to the joints enabled the material 

to also serve as the air and water resistive barrier, providing potential cost savings. Easily 

installed plastic window pan flashing is an appealing part of the overall package.

General observations and items that require further analysis and development are described 

below:

5.1.1 Construction Detailing

The foam may require additional blocking to 

provide adequate nail base at vertical 

transitions of materials. The goal is to 

develop a corner framing detail that 

accommodates varying foam thicknesses 

without creating a wood thermal bridge while 

providing a nailing surface for the corner 

molding and siding edge.
47

The detail at the bottom of the wall needs to 

be considered and resolved. The group 

discussed common finish options, including 

adding a finish blocking strip and/or an 

insect screen or leaving the foam exposed.

5.1.2 Installing Windows and Doors

Cutting out openings with a router creates 

debris that must be cleaned up. The proper 

tool was not available for the mockup. The 

routing bit would need to be sufficiently long 

to allow the router lead edge to rest on and be 

guided by the framed opening. Using a 

routing tool is a relatively fast process; 

cutting openings with reciprocating saws 

took longer and was awkward, less accurate,

and created more debris. Even where the 

routing was imprecise, the exposed area was 

small and easily patched. Getting the proper 

routing tool is crucial. The preferred tool for 

this application would be a hot wire or hot 

knife.
48

When 1 in. of foam sheathing is added to a 2

× 4 frame wall assembly, standard 4-6/16 in.

depth door jambs will need a 1 in. extension 

applied to the interior to provide a flush 

surface for the interior trim attachment. 

Standard hinges typically allow a 1 in.

extension to the interior without limiting a 

full 180° door swing. When 2 in. foam 

sheathing is added to a 2 × 4 frame wall 

assembly, standard 6-9/16 in. jambs can be 

used with no additional steps.

How the window is supported when 

cantilevered over the foam could have a 

significant influence on the framing details. 

Kinro (the HUD industry’s major window 

supplier) volunteered to conduct tests of 

windows on foam with various foam 

densities, bearing and siding materials. 

Testing will focus on the robustness of the 

fastening under cyclical loading.
49

Various window framing options were 

explored (Figures 32 through 34, Details 1–

3). The Kinro evaluations will be based on 

simplest of these options (photo above) 

where the window is resting partly on the sill 

or entirely on the insulation. The protruding 

frame (see photo) was designed to provide 

the window with solid wood bearing looked 

feasible, but it was cumbersome to fabricate 

and install (cutting and fitting lumber for 

each opening). This is a less desirable 

solution. Installation of the metal L-section 

providing a rigid surface for the window to 

sit on needs work (metal supplied for the 

mockup was too thick for practical use) and 

was the least desirable solution. The latter

option would require cutting metal sections 

that might prove difficult to install and 

creates a thermal bridge.

5.1.3 Fasteners

Dow representatives indicated that the 

insulation fastening schedule developed for 

site builders may not apply to factory 

building. In the plant, the material needs to 

be held in place only until the siding is 

applied with fasteners sufficient to hold both 

insulation and siding, which is simpler 

anyway since, unlike site building,

construction is not affected by the weather.
50

Penetration into the structural sheathing or 

framing is a function of the siding material. 

For attaching vinyl, 3⁄4 in. penetration is 

required—5⁄8 in. OSB may be sufficient. For 

1 in. foam, a 3 in. nail was used in the 

mockup to attach the siding. Heavier siding 

material, such as LP SmartSide and 

Cempanel, will require deeper penetration 

into the framing. LP is working on 

details/allowable fasteners when 2 in. foam is 

specified. 1x furring is being considered.

During testing and possibly transport and 

wall build, vibrations may cause nail popping 

possibly because foam is resilient. This issue 

needs more research. It should be noted that 

the gun used to attach the siding did not have 

a pressure regulator. Correct and consistent 

air pressure might have resolved the popping 

issue.
51

Siding was dimpled when fastening guns 

were used to apply siding over foam. This 

can be addressed by using adjustable 

pressure guns. Having to adjust the gun 

pressure on the line for different products 

was cited as a possible drawback.

5.1.4 Assembly/Production

Foam boards were easy to position and tack 

in place. Also it was easy to rout out 

openings.
52

Tape was applied to seal joints, enabling the 

wall to act as an air and moisture barrier. The 

tape was relatively easy to apply to the 

mockup. This might be a bit harder on the 

line since the tape extends to the top of the 

wall. However, applying tape was considered 

far easier and less work than adding a 

separate air barrier (e.g., Tyvek).

Securing the siding through foam is more 

challenging since the fasteners need to travel 

farther (through the insulation) before hitting 

the studs. Finding studs could be expedited 

by printing stud lines on the insulation board.
53

Any impact on the wall after siding 

attachment poses the risk nails popping off 

the surface that will need to be hammered 

back, a step that will slow production. 

Screws would eliminate this problem but 

would cost more and take more time to 

install.

Dow plastic flashing was easy and quick to 

install and appeared to be a good solution for 

plant production.

The thicker Dow board (R-10) looked to 

pose no additional installation problems 

(based on the limited mockup assessment). 

However, this solution is more susceptible to 

above mentioned tests related to window 

bearing. Thicker insulation will require a 

long, expensive screw for attaching the 

furring needed to secure the siding. This 

solution needs more design/development.

5.1.5 Racking Test Results

Four walls using Dow Styrofoam were tested for racking strength distinguished by the type of 

siding applied and the use of interior gypsum board. The results are shown in Table 20 below.
54

Table 20. Racking Test Results—Stud Walls With Styrofoam

Case No. R-Value 

(thickness) Siding Gypsum Board Present

Ultimate Load

lb plf*

RD1 (a) R-5 (1 in.) LP SmartSide Yes 6,701 335

RD1 (b) R-5 (1 in.) LP SmartSide No 5,842 292

RD2 (a) R-5 (1 in.) Cempanel Yes 4,523 226

RD2 (b) R-5 (1 in.) Cempanel No 6,200 310

* Assumes a 2.5 safety factor

Results and examination of the panels after testing suggest the following:

All achieved the target 210 plf, including two 

walls built without interior gypsum. The 

siding (LP SmartSide and Cempanel) likely 

contributed some shear value.
55

The ultimate load for RD2(a) was lower than 

RD2(b), despite the addition of gypsum 

board. This is a counterintuitive result and 

suggests the preliminary nature of these tests. 

The low strength of RD2(a) is an outlier and 

suggests that this test should be revisited.

The RD1 tests indicated that the addition of 

gypsum adds to the shear strength, as 

expected.
56

Examination of the test samples indicated 

that the fasteners in the foam bent in two 

dimensions—a result of cantilevering the 

nails.

5.2 Stud Walls With Foam-Control Nailbrace

The AFM Nailbrace panel design is quite responsive to the industry-authored component 

specifications. The product offered in a single application structural capacity, CI, a nailing 

surface for the siding material and an air barrier. The combination promised to eliminate steps in 

the manufacturing process. During the mockup process, however, several significant hurdles to 

the use of the product in a manufacturing setting were uncovered. These are described in the 

sections below. The mockup and shear testing involved one foam type and thickness, although it 

should be noted that Nailbrace can be manufactured in varying thicknesses with different OEM 

produced insulation materials.
57

5.2.1 Construction Detailing

The use of any foam product creates issues 

with detailing corners particularly evident 

when vinyl siding is used. The goal is to 

develop a corner framing detail that 

accommodates varying foam thicknesses 

without creating a wood thermal bridge while 

providing a nailing surface for the corner 

molding and siding edge.

The detail at the bottom of the wall needs to 

be considered and resolved. The group 

discussed common finish options including 

adding a finish blocking strip and/or an 

insect screen or leaving the foam exposed. 

The manufacturer noted that they have 

details to finish the base of the Nailbrace to 

protect against intrusion from rodents and 

insects.
58

The pattern of inset nailing strips is confined 

to verticals spaced 16 in. oc (closer for the 

edge strips). This raised two concerns. First, 

the lack of a nailing surface at the top and 

bottom plates meant that no fasteners were at 

the top and bottom of the panel (sacrificing 

potential shear resistance) or requiring that 

screws be used in these areas will have 

negative cost consequences. These 

limitations were also an issue at seams that 

do not fall on the 16 in. grid, such as at 

openings.

Nailbrace can perform its bracing benefit 

only if attached with screws; nails are not 

sufficient. Screws are applied through the 

nailstrips and along the top and bottom of the 

Nailbrace into the foam, driven so that the 

screw heads finish snug against the nail strips 

and at the foam just below the surface of the 

foam face. The technique of screwing 

through the foam works at terminations 

around all openings as well. 

5.2.2 Installing Windows and Doors

Cutting out openings with a router creates 

debris that must be cleaned up. The proper 

tool was not available for the mockup. The 

routing bit would need to be sufficiently 

long to allow the router lead edge to rest on 

and be guided by the framed opening. Using 

a routing tool is a relatively fast process; 

cutting openings with a Sawzall took longer 

and was awkward, less accurate, and created 

more debris. Even where the routing was 

imprecise, the exposed area was small and 

easily patched. Getting the proper routing 

tool that can cut structural sheathing and 

foam is crucial.
59

Detailing of door needs consideration to 

make sure hinge action (door swing) is not 

constrained by the foam thickness.

How the window is supported when 

cantilevered over the foam could have a 

significant influence on the framing details. 

Kinro (the HUD industry’s major window 

supplier) volunteered to conduct tests of 

windows on foam with various foam 

densities, bearing and siding materials. 

Testing will focus on the robustness of the 

fastening under cyclical loading.
60

Various window framing options were 

explored. The Kinro evaluations will be 

based on simplest of these options (see 

photo above) where the window is resting 

partly on the sill or entirely on the 

insulation. Installation of the protruding 

frame designed to provide the window with 

solid wood bearing looked feasible but 

cumbersome and took time to install 

(cutting and fitting lumber for each 

opening). This was a less desirable solution. 

Installation of the metal L-section (see 

photo) providing a rigid surface for the 

window to sit on needs work (metal 

supplied for mockup was too thick for 

practical use) and was the least desirable 

solution. This option would require cutting 

metal sections that might prove difficult to 

install and provides a thermal bridge. AFM 

suggested applying a strip of insulating 

foam tape to the inboard flange of the metal 

clip to break the thermal bridge. Metal clips 

will be made in a series of lengths—1 ft to 8 

ft, and can be used in combination when 

doing assembly thereby obviating the need 

to cut pieces at the plant and fabricated 

using thinner material (e.g., 22 gauge) for 

easier penetration by screws and siding 

nails.
61

Routing of openings was done from the 

inside using a Sawzall. This sped up the 

process—the harder surface to cut 

(structural sheathing) is in contact with the 

stud that serves as a guide. Cutting from the 

inside may be easier to do on a production 

basis.

5.2.3 Fasteners 

In general, it appeared that nails won’t 

provide sufficient fastening strength. This 

may be because the strips are embedded in 

the foam which has a tendency to flex 

pulling the nails out of the framing. If 

screws are required in order for the fastener 

to grip the OSB/framing, the material cost 

and labor required for panel installation will 

increase, potentially significantly.
62

Use of screws is more likely to be justified 

if used in limited application (e.g., end 

walls) and if those shear walls can develop 

sufficient strength. Unfortunately, collated 

screws were not available for the tests but 

the plant will consider running an additional 

racking test with screws, including fasteners 

along the top and bottom plates.

The LP representative indicated that the 

OSB would not count toward the required 

depth of nail penetration for the Smart Side 

product.
63

The thickness of the insulation made it more 

difficult to hit the studs with the fasteners, a 

limitation of sheathing materials in general.

Siding was dimpled when fastening guns 

were used to apply siding over foam. This 

can be addressed by using adjustable 

pressure guns. Having to adjust the gun 

pressure on the line for different products 

was cited as a possible drawback. This 

drawback might be addressed by the use of 

different fasteners and tools.

It was evident that the use of a new material 

such as foam sheathing will require worker 

training, careful execution and proper tools.
64

5.2.4 Assembly/Production

In a single product, Nailbrace serves the 

functions of several different products 

currently installed in multiple layers over 

the wall (structural sheathing, insulation, 

WRB, furring for siding application). This 

is potentially a significant cost saver in 

terms of time, possibly material, and 

inventorying costs, and could increase 

plant throughput.

Except for creating a starter hole, cutting 

the panels for openings posed no 

extraordinary challenges. A proper routing 

tool (deep enough for the panel and capable 

of cutting OSB and foam at the same time) 

is essential for this option to work.
65

The panel weights make having two 

workers essential to installation on the line, 

but this is probably similar to (no more 

difficult than) installing structural 

sheathing. The weight of the foam and 

nailstrips adds less than 10 lb to an OSB 

sheet that weighs 45 lb.

5.2.4.1 Racking Test Results

Two walls using AFM Nailbrace were tested for racking strength one with and the other without 

interior gypsum board. It should be noted that Nailbrace was not fastened at the top and bottom 

plates for these tests.

20 AFM noted that attaching Nailbrace with screws will substantially 

improve the load capacity of the wall. The results are shown on Table 21 below. 

Table 21. Racking Test Results—Stud Walls With Foam-Control Nailbrace

Case No. R-value 

(thickness) Siding Gypsum Board Present

Ultimate Load

lb plf*

RA1 (a) R-5 (15⁄8 in.) LP SmartSide Yes 7,154 357

RA1 (b) R-5 (15⁄8 in.) LP SmartSide No Excessive 

deflection na

* Assumes a 2.5 safety factor.

 20 Absence of let-in bracing at the top and bottom was discussed after the tests but not pursued since this option was 

dropped from further consideration.
66 

Results and examination of the panels after testing suggest the following:

The wall with the gypsum board attained a 

significant ultimate load when used in 

combination with the Nailbrace. The lack of 

nailing at the top and bottom plate is likely to 

have significantly reduced the racking 

strength of the wall.

During testing, the RA1(b) wall deformed, 

coming in contact with the testing device (see 

photo above) prior to failure due to bending 

of the fasteners. This negated the result and 

created a challenge to applying the racking 

apparatus.

Fleetwood expressed interest in running an 

additional shear test on Nailbrace using 

screws instead of nails. Tests should be run 

with screws all around the perimeter, 

including top and bottom plates. 
67

6 Conclusions

The research described in this report is part of a multiphase program with the goal of identifying 

and moving toward commercial acceptance of envelope construction methods that are far more 

efficient than current practice and specifically geared to meet the needs of factory builders. This 

current effort is focused on wall component development and involved two parts: identifying a 

range of building solutions that had in common the use of continuous exterior insulation and 

initial testing of some of the solutions developed.

In identifying solutions the team reached out to six of the nation’s leading insulation suppliers,

challenging them to suggest how off-the-shelf or readily developable products could be used as 

part of a comprehensive solution that meets a set of prescribed performance targets. The results 

were presented at an Expert Meeting in November 2012. This was a fruitful endeavor with a total 

of more than 50 unique solutions presented and discussed. In addition to building an impressive 

array of possible technical solutions, the experience reinforced the value of collaborative 

research that can result when all stakeholders are invested as research partners. Among other 

benefits, the team and industry committee were able, with the help and guidance of the insulation 

companies, to begin to comparatively assess a range of alternate construction methods and 

materials in a short period of time and to begin to identify materials and solutions that have the 

greatest potential for factory builders. Specifically, the process is enabling the team to explicitly 

weigh alternatives based on a number of parameters (manufacturability, thermal performance, 

moisture balance, etc.) and not just first cost.

Among the observations and conclusions of the design-development stage with the six insulation 

suppliers are the following:

• The decision about the materials that can be part of a continuous exterior insulation 

solution will partly depend on the location of the VR. The appropriate location of the VR

and the relative perm ratings of materials in the wall continue to be debatable within the 

industry. These issues will require additional analysis and testing to settle following 

which changes and clarifications will be needed within building codes, particularly the 

HUD standards.

• A single product that can be delivered by OEM insulation suppliers that can perform 

multiple functions (weather barrier, air barrier, structural capacity, etc.) will have an 

advantage by enabling manufacturers to eliminate production steps associated with 

applying additional materials to perform those functions. However, these advantages will 

come with a cost that will need to be carefully weighed against the benefits.

• In the factory building environment where production speed is a principle determinant of 

profitability, seemingly small considerations, like required fasteners, weight (i.e., 

transportability) of materials and simplicity of detailing become paramount. For example, 

technologies that require screws in place of nails may dramatically slow the production 

process. 

• Wall technologies that meet the needs of factory building are proving to be, in many 

respects, too broad a goal: solutions that are appealing for manufactured home builders 

may not suit modular builders, and vice versa. This is less a matter of building method 

than home price point and market orientation (e.g., some factory builders will use very 
68

high insulation levels to distinguish their homes and are less concerned about cost 

because of the relatively high price point). While the project will continue to pursue 

solutions for both audiences, the technical direction may need to branch in two directions 

to serve the needs of both.

• There continue to be unresolved technical issues associated with the use of exterior foam 

insulation that, in many instances, are being addressed by others in parallel with this 

work. For example, the durability of windows that, while fastened into the structural 

frame, bear on the insulation is under consideration. The results of those investigations

will benefit this research and help the larger building community looking to use exterior 

foam insulation.

Among the key findings from the limited testing and mockups of the wall designs proposed by 

Dow and AFM are the following general points:

• The general sense of the technical review group was that Dow’s Styrofoam has real 

potential and the hurdles to its use and additional effort that will be required to reach 

proof-of-concept is manageable—Styrofoam is a promising product for factory builders. 

However, questions about cost, compliance with HUD standards, and production 

friendliness will need to be addressed.

• AFM’s Nailbrace has much to recommend it, including its ability to be an almost-all-inone wall solution. However, the preliminary reaction of the industry and supplier group 

assembled for the test is that the product has significant drawbacks (e.g., need to use 

screws instead of nails, lack of flexibility with regard to furring location, weight of the 

panel) that represent formidable hurdles weighing against this option. 
69

References

ASTM E564 ― Standard Practice for Static Load Test for Shear Resistance of Framed Walls for 

Buildings, published by ASTM International, www.astm.org. 

ASTM E72-80 ― Standard Test Methods of Conducting Strength Tests of Panels for Building 

Construction, published by ASTM International, www.astm.org. 

BASF. (2013). “R-Value Data for NEOPOR Rigid Thermal Insulation Produced Under Brand 

Marketing Agreement in the US and Canada.” Memorandum dated January 15, 2013. 

Wyandotte, MI: BASF. http://styropor.basf.us/files/pdf/2013_01_15_Neopor_Rvalue_Comprehensive.pdf. Accessed November 2013.

BASF. (2011). Building and Modernizing With NEOPOR. Ludwigshafen, Germany: BASF. 

www.plasticsportal.net/wa/plasticsEU~en_GB/function/conversions:/publish/common/upload/fo

ams/Neopor_Building_and_modernising_with_Neopor_EN.pdf. Accessed November 2013.

BASF. (2012). “Wall Insulation.” Wyandotte, MI: BASF. 

www.neopor.basf.us/files/pdf/wall.pdf. Accessed November 2013.

CertainTeed. (2010). “CertaPro Commercial Board Specification Sheet.” Valley Forge, PA: 

CertainTeed. www.certainteed.com/resources/30-25-021%20CertaProComBoard%20Spc.pdf. 

Accessed November 2013.

Fox, P.J. (2012). “Building America Advanced Envelope Research—BASF NEOPOR.”

Presented at the Building America Expert Meeting, Harrisburg, PA.

HUD. U.S. (1994).Manufactured Housing Construction and Safety Standards, Subpart 3280. 

Washington, D.C.: U.S. Department of Housing and Urban Development. 

JM. (2013a). “Flat & Tapered ValuTherm Polyisocyanurate Roof Insulation.” Denver, CO: 

Johns Manville. www.specjm.com/files/pdf/RS-5174_ValuTherm.pdf. Accessed November 

2013.

JM. (2013b). “ValuTherm Roof Insulation.” Denver, CO: Johns Manville.

www.specjm.com/files/pdf/RS-5174_ValuTherm.pdf. Accessed November 2013.

JM. (2013c). “AP Foil-Faced Polyiso Foam Sheathing.” Denver, CO: Johns Manville.

http://www.specjm.com/products/foamboards/APFoilFacedPolyisocyanurateFoamSheathing.asp. Accessed November 2013.

JM. (2009). “AP Foil-Faced Polyisocyanurate Foam Sheathing.” Denver, CO: Johns Manville. 

www.jm.com/insulation/building_insulation/products/can283_ap_foilfaced.pdf. Accessed 

November 2013.
70

Levy, E.; Mullens, M.; Tompos, E.; Kessler, B.; Rath, P. (2012). Building America Expert

Meeting Report: Advanced Envelope Research for Factory Built Housing. Golden, CO: National 

Renewable Energy Laboratory. NREL/SR-5500-54439.

Lstiburek, J. (1999). Drainage Planes and Air Spaces. Research Report-9909. Somerville, MA: 

Building Science Corporation. www.buildingscience.com/documents/reports/rr-9909-drainageplanes-and-air-spaces. Accessed November 2013. 

Lstiburek, J. (2006). “BSD 105: Understanding Drainage Planes.” Building Science Digests. 

Somerville, MA: Building Science Corporation. www.buildingscience.com/documents/digests/ 

bsd-105-understanding-drainage-planes. Accessed November 2013. 

Mallon, B.; Lieburn, B. (2012). “Moisture Protection and Energy Efficiency—Advances in Wall 

Construction for Energy Efficiency for Factory Built Homes.” Presented at the Building America 

Expert Meeting, Harrisburg, PA.

ORNL. (2013). Oak Ridge National Laboratory. “WUFI Software.” Oak Ridge, TN: Oak Ridge 

National Laboratory. http://web.ornl.gov/sci/ees/etsd/btric/wufi/software.shtml. Accessed 

November 2013.

Tobin, M. (2012). “Presentation to the ARIES Collaborative Building America Advanced 

Envelope Research.” Presented at the Building America Expert Meeting, Harrisburg, PA.
71

Appendix A: Detailed Test Description

The following tables provide details on the racking tests and mockups conducted on the 

Styrofoam and Nailbrace-based wall design options. Tabulated information includes intent of 

test, fastener type for components, wall framing, window framing and other details. Fasteners 

have been keyed to a list of all the different types used for the project (see Table 26 and 

Table 27).

Table 22 provides this information on racking tests conducted on multiple iterations of stud walls 

with Styrofoam.
72

Table 22. Details on Racking Tests—Stud Walls With Styrofoam

Case 

No.

Insulation

Framing

Furring or Strapping Siding

Notes Purpose Ultimate

R-Value Load

(thickness) Fastener Type Fastener Type Fastener

RD1

(a)

R-5

(1 in.)

Staple, roof 

nail or cap nail 

(13⁄4 in.) (B)

2 in. × 

6 in. NA NA LP SmartSide 3⁄8 in.

Nail 

(3 in.)

(D)

5

Baseline for assessing 

structural integrity of 

wall with gypsum 

board.

6,701 lb

RD1

(b)

R-5

(1 in.)

Staple, roof 

nail or cap nail 

(13⁄4 in.) (B)

2 in. × 

6 in. NA NA LP SmartSide 

3⁄8 in.

Nail 

(3 in.)

(D)

5, 7

Contrast result of wall 

RD1(a) without 

gypsum

5,842 lb

RD2

(a)

R-5

(1 in.)

Staple, roof 

nail or cap nail 

(13⁄4 in.) (B)

2 in. × 

6 in. NA NA Cempanel

Nail 

(3 in.)

(D)

Contrast shear

resistance result with 

LP SmartSide (RD1).

4,523 lb

RD2

(b)

R-5

(1 in.)

Staple, roof 

nail or cap nail 

(13⁄4 in.) (B)

2 in. × 

6 in. NA NA Cempanel

Nail 

(3in.)

(D)

7

Contrast result of wall 

RD2(a) without 

gypsum 

6,200 lb

RD3 R-10

(2 in.)

Staple, roof 

nail or cap nail 

(23⁄4 in.)

(M or L)

2 in. × 

4 in. 2 × 4

HeadLOK 

24 in. o.c. 

vertical 

spacing (O)

LP SmartSide 

3⁄8 in.

Nail (2 

in.)

(C)

5, 6

Assess the impact that a 

longer fastener has on 

the shear strength of the 

wall.

Not tested

Notes:

1. Most testing to be completed (if possible) prior to February 6. Test RD3 will be conducted on February 6 in the morning. While not intended as 

“witnessed” ASTM tests, the results are intended to provide a rough gauge on how these walls would likely test out by a third party.

2. All walls except RD3 have interior gypsum board finish with PVA adhesive.

3. No fiberglass insulation or weather barrier required for testing.

4. Panel is an opaque wall section (no windows or doors)

5. LP SmartSide requires 11⁄2 in. penetration into structural framing. Siding to be removed after tests to inspect for damage to the foam by nail routing.

6. Length of fastener to be verified. LP SmartSide specs for walls with foam insulation > 1 in. requires 11⁄2 in. × 4 in. vertical strapping for nailing base.

7. Wall tested without gypsum for comparison with RD1(a)/RD2(a).

Table 23 provides detailed information on racking tests conducted on multiple iterations of stud walls with Foam-Control Nailbrace.
73

Table 23. Details on Racking Tests—Stud Walls With Foam-Control Nailbrace

Case 

No.

Insulation 

Framing Furring or 

Strapping

Siding 

Notes Purpose Ultimate 

R-Value Load

(thickness) Fastener Type Fastener

RA1

(a)

R-5

(1-5⁄8”)

Nail (3 in.) or

Opt-Screw (3 

in.) through 

vertical strip

(E or H)

2 in. × 6 

in. NA

LP 

SmartSide 

3⁄8 in.

2 in. nail (6d 

ring shank nail) 

(attached to 

vertical strip) 

(C)

5

Baseline for assessing 

structural integrity of 

wall

Routing out of insulation 

by nails following 

racking test.

7,154 lb

RA1

(b)

R-5

(1-5⁄8”)

Nail (3 in.) or

Opt-Screw (3 

in.) through 

vertical strip

(E or H)

2 in. × 6 

in. NA

LP 

SmartSide 

3⁄8 in.

2 in. nail (6d 

ring shank nail) 

(attached to 

vertical strip) 

(C)

5, 6 Contrast result of wall 

RA1 without gypsum.

Excessive 

deflection

RA2 R-10

(2-7⁄8”)

Nail (4 in.)

through 

vertical strip

(G)

2 in. × 4 

in. NA

LP 

SmartSide 

3⁄8 in.

2 in. nail (6d 

ring shank nail) 

(attached to 

vertical strip) 

(C)

5, 7 Case RA1 with thicker 

insulative sheathing. Not tested

Notes:

1. Testing to be completed (if possible) prior to February 6.

2. Wall has interior gypsum board finish with PVA adhesive.

3. No fiberglass insulation or weather barrier required for testing.

4. Panel is an opaque wall section (no windows or doors)

5. The sample will be assembled so that the let in furring strips receive the nails or screws and, together with the structural sheathing is assumed to 

contribute to wind bracing. This is required to secure the strip for when it receives the siding.

6. Wall tested without gypsum for comparison with RA1.

7. This test is tentative and will be conducted only if time allows.

Table 24 provides detailed information on process mock-ups conducted on multiple iterations of stud walls with Styrofoam. For 

details on window framing options see Section 4.6.4. 
74

Table 24. Details on Mockups—Stud Walls With Styrofoam

Case 

No.

Insulation

Structural Sheathing

Framing

Furring or

Strapping Siding Window

Framing

Notes

Purpose

R-Value 

(thickness)

Fastener

Type

Fastener

Type

Fastener

Detail No.

Fastener

MD1 R-5

(1 in.)

Staple, roof nail 

or cap nail (13⁄4

in.) (B)

No 2 in. × 

6 in. NA NA

LP 

SmartSide 

3⁄8 in.

Nail 

(3 in.)

(D)

1 –

• Baseline for construction evaluation

Evaluate construction details at 

openings and roof and floor 

intersections

Assess difficulty in routing out for 

openings

MD2 R-5

(1 in.)

Staple, roof nail 

or cap nail (13⁄4

in.) (B)

No 2 in. × 

6 in. NA NA Vinyl

Nail 

(3 in.)

(D)

3 –

• Assess additional issues or 

advantages (speed of assembly) when 

using vinyl siding with staples. 

MD3 R-5

(1 in.)

Staple, roof nail 

or cap nail (13⁄4

in.) (B)

Yes 

(OSB)

2 in. × 

6 in. NA NA Vinyl 

Nail 

(3 in.)

(D)

2 –

• Represent typical construction

Assess difficulty in routing out for 

openings

MD4 R-10

(2 in.)

Staple, roof nail 

or cap nail (23⁄4

in.)

(M or L)

No 2 in. × 

4 in. 2 × 4

HeadLOK 

24 in.o.c. 

vert. 

spacing

(O)

LP 

SmartSide 

3⁄8 in.

Nail 

(2 in.)

(C)

1 – 3

• Evaluate construction details at 

openings and roof (side and gable 

end) and floor intersections

Assess difficulty in routing out for 

openings

Notes:

1. Omit gypsum and fiberglass from mockup walls to view missed fasteners from siding to studs. Include flashing around windows and doors, air barrier 

and tapes as required for a typical installation.

2. Reuse windows and doors, if possible.

3. Test MD4 will be conducted only if time allows.
75

Table 25 provides detailed information on process mock-ups conducted on multiple iterations of stud walls with Foam-Control 

Nailbrace.

Table 25. Details on Mockups—Stud Walls With Foam-Control Nailbrace

Case 

No.

Insulation 

Structural 

Sheathing

Framing

Siding Window

Framing

Notes

Purpose

R-value 

(thickness

)

Fastener

Type

Fastener

Detail No.

Fastener

MA1 R-5

(1-5⁄8”)

Nail (3 in.) 

through 

vertical strip

(E or H)

No 2 in. × 

6 in.

LP 

SmartSide 

3⁄8 in.

2 in. nail (6d 

ring shank nail) 

(attached to 

vertical strip) 

(C)

1 – 3, 4

• Baseline for construction evaluation

• Evaluate construction details at 

openings and roof (side and gable end) 

and floor intersections

• Assess difficulty in routing out for 

openings

MA2 R-5

(1-5⁄8”)

Nail (3 in.)

through 

vertical strip

(E or H)

No 2 in. × 

6 in. Vinyl Staple into nailing strip (C) 3 – 4

• Assess additional issues or advantages 

(speed of assembly) when using vinyl 

siding with staples.

MA3 R-5

(1-5⁄8”)

Nail (3 in.)

through 

vertical strip

(E or H)

No 2 in. × 

6 in. Vinyl Staple into nailing strip (C) 2 4

• Assess additional issues or advantages 

(speed of assembly) when using vinyl 

siding with staples.

Notes:

1. Omit gypsum and fiberglass from mock up walls to view missed fasteners from siding to studs. Include flashing around windows and doors, air barrier and tapes as 

required for a typical installation.

2. Reuse windows and doors, if possible

3. Specification of the fastener for attaching the siding is based on LP Technical Bulletin SIP No. 2074, Table 4 (http://www.rcontrol.com/downloads/techbulletin/rcontrol2074.pdf)

Fastener for Nailbrace assumed to penetrate a total of 11⁄2” of the structural sheathing and structural framing. The siding is held by the nail into the vertical strip 

embedded in Nailbrace.
76

Appendix B: Equipment and Material Needs

The section provides details on the equipment and material needs for the testing and 

demonstration.

Fasteners and Associated Tools

Fasteners and associated tools required for the meeting are listed in Table 26 and Table 27.

Table 26. Fasteners and Associated Tools (Senco Products)

Code Fasteners 

Standard Description Quantity Thousands Finish

A Q25BAB 21⁄2 in. × 7/16 Crn 15 Ga Staple 2 carton 10/m Galv

B P21BAB 2 in. × 1 in. Crn 16 Ga Staple 2 carton 10/m Galv

C G621ASBX 2 in. × 0.113 RS Nail 2 carton 5/m Hot dip 

galv

D H627ASBX 3 in. × 0.120 RS Nail 2 carton 5/m Hot dip 

galv

E K528ASBX 31⁄4 in. × 0.131 Coated Nail 2 carton 5/m Hot dip

galv

F K529APBX 31⁄2 in. × 0.131 Coated Nail 2 carton 5/m Bright

G KC31 4 in. Nail – – –

Code Screws Description Quantity Thousands Finish

H 08F300Y 3 in. × # 8 Wood Screw 2 tubs 1.6/m Yellow 

Zinc

Code Special Product Description Quantity – Finish

I SQSSXP 3.5 90MM Europe 1

J WC130SP 41⁄2 in. wide crn Europe 1

K S28BAB 3 in. × 1/2 in. Crn Staple Europe 3 carton Galv

L S29BAB 31⁄2 in. × 1⁄2 in. Crn Staple Europe 3 carton Galv

M SP30BAB 4 in. × 1 in. Crn Staple Europe 4 carton Galv

N SP29BAB 31⁄2 in. × 1 in. Crn Staple Europe 4 carton Galv

Tool Identifier Description Quantity – –

4Y0001N WC200 XP WC Stapler 2

5B0001N SN951XP Framing Nailer 2

660101N SQS55 Stapler 2

6Y00011N DS340A/C Screwdriver 1

2P0001N DS275-18V Cordless Screwdriver 1
77

The following screws were used to attach 2 × 4 (nominal) furring over 2 in. of Styrofoam with 2 

in. embedment into the studs. Screws require Spider drive bits.

Table 27. Fasteners and associated tools (FastenMaster products)

Code Screws Description Quantity Pieces Finish

O HeadLOK 51⁄2 in. min 1 box 50

Insulation and Associated Products

Styrofoam tests (Supplier: DOW)

• 1—Pallet or unit of 4 ftx9 ftx1 in. Dow Styrofoam sheathing panels 96 pcs.

• 1—Pallet or unit of 4 ftx9 ftx2 in. Dow Styrofoam sheathing panels 48 pcs.

• 1—Froth Pak 220 (insulation not sealant) kit, with hose and nozzles

• 1—Case of Great Stuff Gaps and Cracks Pro

• 1—Case of Great Stuff Adhesive

• 1—Case of Great Stuff Window and Door Pro

• 2—Pro 14 Great Stuff Dispensers (guns)

• 1—Case of Great Stuff gun cleaner

• 1—Case Weathermate Construction Tape 2.875 in. wide

• 1—Case Weathermate Construction Tape 1.875 in. wide

• 1—Case of Weathermate Straight Flashing 4 in. × 100 ft

• 1—Case of Weathermate Straight Flashing 6 in. × 100 ft

• 1—Box Weathermate Flexible Flashing 6 in.

• 1—Box Weathermate Flexible Flashing 9 in.

• 1—Box Weathermate window sill pans

Foam-Control Nailbrace tests (Supplier: AFM Corp.)

• 6 pieces—1.625 in. × 4 ft × 8 ft, Foam Control Nailbrace panels

• 8 pieces—1.625 in. × 4 ft × 9 ft, Foam Control Nailbrace panels

• 4 pieces—2.875 in. × 4 ft × 9 ft, Foam Control Nailbrace panels

• 6 rolls edge sealing tape

Siding

LP SmartSide siding (Supplier: LP Corp.)

• 18 each—3⁄8 in. 4 ft × 8 ft 8 in. o/c SmartSide Panel Siding

• 18 each—7/16 in. 4 ft × 8 ft 8 in. o/c SmartSide Panel Siding
78

Cempanel (Supplier: Cavco)

• 10 sheets—4 ft × 8 ft each

Vinyl (Supplier: BlueLinx Corp.)

• 32 squares—D5 Dutch Lap Parkside #115 Pearl

• 50 pieces—Sturdy Vinyl Starter Strip #303

• 40 pieces—5⁄8 in. J-Channel Pearl #36585

• 10 pieces—3 in. Outside Corner Post Pearl #40022

• 10 pieces—4 in. Outside Corner Post Pearl #40020

Window Framing

Metal L-clips (Supplier: AFM Corp.)

• 10 pieces—4 ft long R-5 L-clips

• 4 pieces—R-10 L-clips

Other Wall Build Materials (Supplier: Cavco) (quantities as required)

• Framing

• Gypsum board

• OSB

• Doors

• Windows and doors

• Flashing

• Weather resistant barrier

• Materials for partial floor and roof 
DOE/GO-102014-4293 ▪ January 2014

Printed with a renewable-source ink on paper containing at 

least 50% wastepaper, including 10% post-consumer waste.

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