2024 International Building Code® Updates – Fire Safety Provisions for Exterior Wall Assemblies, Foam Plastic Insulations, Section 104  

“INSULATED VINYL SIDING. A continuous insulation cladding product, with manufacturer-installed foam plastic insulating material as an integral part of the cladding product, having a thermal resistance not less than R-2.”

“PEER REVIEW. An independent and objective technical review conducted by an approved third-party.”

“RAINSCREEN SYSTEM. An assembly applied to the exterior side of an exterior wall and consisting of, at minimum, an outer layer, an inner layer and a cavity between them sufficient for the passive removal of liquid water and water vapor.”

“RESPONSIVE VAPOR RETARDER. A vapor retarder material complying with a vapor retarder class of Class I or II, but that also has a vapor permeance of 1 perm or greater in accordance with ASTM E96, water method (Procedure B).”

Turning to existing terms, there are some notable revisions. The EXTERIOR WALL ENVELOPE term is now EXTERIOR WALL ASSEMBLY along with some further substantive modifications enhancing clarity:

2021 IBC text:

“EXTERIOR WALL ENVELOPE. A system or assembly of exterior wall components, including exterior wall covering materials, that provides protection of the building structural members, including framing and sheathing materials, and conditioned interior space, from the detrimental effects of the exterior environment.”

2024 IBC text (revisions in bold):

“EXTERIOR WALL ASSEMBLY. A system including the exterior wall covering, framing, and components such as weather-resistive barriers and insulating materials. This system provides protection of the building structural members and conditioned interior space from the detrimental effects of the exterior environment.

“Envelope” when used in reference to buildings is much more a term of building science and energy efficiency. In the context of IBC requirements, however, the “exterior wall envelope” term and its definition were somewhat confusing. The term seemed to present more focus on the concept of what an exterior wall “does” (i.e., its function) vs. what an exterior wall “is” (i.e., its composition). Such a distinction is important given the scope and purpose of the IBC and its structural and fire performance provisions that include requirements referencing test methods that evaluate assemblies. To this point, revision to the EXTERIOR WALL ENVELOPE term is accompanied by multiple associated revisions to its use throughout the code(s).

The EXTERIOR WALL COVERING term was revised to include the new RAINSCREEN SYSTEM term.

2024 IBC text (revisions in bold):

“EXTERIOR WALL COVERING. A material or assembly of materials applied on the exterior side of exterior walls for the purpose of providing a weather-resisting barrier, insulation or for aesthetics, including but not limited to, veneers, siding, exterior insulation and finish systems, rainscreen systems, architectural trim and embellishments such as cornices, soffits, fascias, gutters and leaders.”

This revision clarifies for code users that rainscreen systems are a type of exterior wall covering where the new definition of rainscreen system further clarifies for the code user more precisely what comprises a rainscreen system.

LISTED was revised to include several examples of common industry/marketplace terminology used to identify equipment, products, or materials that are listed by third-party listing agencies (2024 IBC text [revisions in bold]):

LISTED. Equipment, materials, products or services included in a list published by an organization acceptable to the building official and concerned with evaluation of products or services that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services and whose listing states either that the equipment, material, product or service meets identified standards or has been tested and found suitable for a specified purpose. Terms that are used to identify listed equipment, products or materials include “listed”, “certified", “classified” or other terms as determined appropriate by the listing organization.

The net, collected effect of these terminology updates is the continuation of the IBC’s iterative evolution that allows for the recognition of new building product technologies, changes to design and construction practices, and industry vernacular to ensure not only the clarity of code requirements but also consistency in their application. Said simply, the words are important.

Photo courtesy of EIFS Industry Members Association (EIMA)

IBC Section 705 provides for fire and smoke protection features applicable to exterior walls of buildings.

IBC CHAPTER 7

IBC Section 705 provides for fire and smoke protection features applicable to exterior walls of buildings. This Section was minimally revised for 2024.

Revisions to Section 705 provisions for exterior walls and exterior wall assemblies include a new Section 705.6 that requires that a fire-resistance rating for an exterior wall must extend from the top of the foundation or floor/ceiling assembly to the underside of either (1) The underside of the floor sheathing, roof sheathing, deck or slab above, or (2) the underside of a floor/ceiling or roof/ceiling assembly above that has a fire-resistance rating equal to or greater than the exterior wall and the fire separation distance is greater than 10 feet.

A second new section was added for the condition where floor assemblies in Type III construction support gravity loads of an exterior wall. The requirement is essentially that the portion of the floor assembly supporting the exterior wall assembly must have a fire-resistance-rating that is equal or greater than that required for the exterior wall assembly in Section 601. The net effect of this new provision is to help ensure continuity of the fire-resistance-rating of the exterior wall from the top of the foundation to the top of the exterior wall.

Photo courtesy of Polyisocyanurate Insulation Manufacturers Association (PIMA)

Chapter 14 of the 2024 IBC contains several useful and important updates for various provisions related to fire safety of exterior walls. The addition of exterior wall assemblies effectively removes any ambiguity around “how much” of the exterior wall is subject to the reach of Chapter 14.

IBC CHAPTER 14

Chapter 14 of the 2024 IBC contains several useful and important updates for various provisions related to fire safety of exterior walls. Revisions range from clarifying the Chapter’s Scope, to provisions regarding vertical and lateral flame propagation, to the addition of three new sections containing requirements for different building products and systems.

Scope

Although a simple revision, Section 1401.1 was revised to include “exterior wall assemblies,” and “exterior soffits and fascias” to the scope of Chapter 14. The addition of exterior wall assemblies effectively removes any ambiguity around “how much” of the exterior wall is subject to the reach of Chapter 14. Use of the updated-for-2024 exterior wall assembly defined term throughout Chapter 14 and the rest of the 2024 IBC also confirms (through the defined term) that exterior wall coverings and water-resistive barriers are components of the exterior wall assembly.

Vertical and Lateral Flame Propagation (NFPA 285)

NFPA 285 testing is a critical component of fire safety in buildings where combustible components are used in exterior wall assemblies of Type I, II, III, and IV construction. The 2024 IBC introduces new sections that collect references to provisions where NFPA 285 testing is required, that add new requirements for NFPA 285 testing, and that prescribe methods for demonstrating compliance. Since the inaugural 2000 edition, reference to and use of NFPA 285 in the IBC has expanded as specific recognition of water-resistive barriers, new lightweight energy-efficient cladding materials and systems, and other building envelope materials, claddings, and design practices have been added to the code. Requirements for NFPA 285 testing are a key contributor to the IBC’s overall approach to fire safety of exterior wall assemblies that also includes, where applicable, provisions regarding ignition resistance and fire-resistance-ratings. The IBC approach has been demonstrably successful at preventing catastrophic fires code-compliant exterior walls of high-rise buildings with combustible claddings. For 2024, a new Section 1402.5 was inserted into the performance requirements for exterior walls to collect the references that has the cumulative effect of:

1. Establishing a specific requirement within Section 1402 for vertical and lateral flame propagation of exterior walls on buildings of Type I, II, III, and IV construction that contain certain combustible components: specifically combustible exterior wall coverings, combustible insulation, or combustible water-resistive barrier (WRB)s.
2. Provides references to other sections of Chapter 14 and 26 where the existing provisions and more specific requirements are located, specifically:
• Section 1402.6 for combustible WRBs (Note: renumbered from 2021 IBC Section1402.5)
• Section 1406 for Metal Composite Material (MCM) systems
• Section 1407 for Exterior Insulation and Insulation (EIFS) systems
• Section 1408 for High-pressure Decorative Exterior-grade Compact Laminate (HPL) systems
• Section 2603 for foam plastic insulation
3. Clarifies that where provisions require compliance with NFPA 285, the exterior wall assembly shall be tested in accordance and comply with the acceptance criteria of NFPA 285.

Section 1402 also includes a new Section 1402.7 with a fire safety provision for a type of exterior wall veneer that is manufactured using combustible adhesives on exterior walls of Type I, II, III, and IV construction that are greater than 40 feet in height above grade plane. The veneers subject to this provision are those where a combustible adhesive is used to laminate a metal core (typically in the form of a honeycomb structure) to noncombustible facings (typically in the form a metal skin). The new provision requires that exterior wall assemblies containing this type of veneer are tested in accordance with, and meet the acceptance criteria of, NFPA 285. (It should be noted that a proposal to add reference to Section 1402.7 to Section 1402.5 was submitted for Group A of the 2024-2026 ICC Code Development Cycle.) This new provision is another example of how the code development process allows IBC to address new building materials, systems, and approaches; in this case ensuring exterior wall assemblies containing combustible cladding components are rigorously tested to prevent fire propagation.

Compliance Methods for Vertical and Lateral Flame Propagation (NFPA 285)

A particularly important revision to the 2024 IBC is the inclusion of a new Section 1402.8 that prescribes three methods for establishing compliance of exterior wall assemblies when the code requires the exterior wall assembly is tested in accordance with, and comply with the acceptance criteria of, NFPA 285. The three compliance methods are:

1. An exterior wall assembly tested in accordance with and meeting the acceptance criteria of NFPA 285.

Method 1 establishes compliance using specific NFPA 285 tests, conducted on test specimens of the specific exterior wall assembly configuration as it is to be constructed. This approach provides the most direct evidence of compliance for a specific set of building materials configured in a specific way.

1. An exterior wall assembly design listed by an approved agency for compliance with NFPA 285.

Method 2 establishes compliance through reference to a wall design that is listed by a third-party agency for compliance with NFPA 285. The wall assembly intended to be built must conform to the design as it is presented, or otherwise recognized, by the listing.

Wall assembly designs listed by a third-party agency are, at a minimum, based on at least one successful NFPA 285 test. Depending on the agency’s certification scheme and the scope of assembly designs recognized by the listing, a listed design might be further supported by additional information and data (up to, and including, multiple NFPA 285 tests). Finally, listing and certification typically requires initial product verification and some amount of ongoing manufacturing quality control and periodic review to maintain the listing.

1. An approved analysis based on an assembly or condition tested in accordance with and meeting the acceptance criteria of NFPA 285.

Method 3 explicitly prescribes the use of analysis to establish compliance. Within this provision, though, are two (2) crucial elements. The first being that the analysis must be based on an assembly or a condition that has been tested and complies with NFPA 285. Such a requirement ensures the starting point of the analysis is an assembly known to comply with NFPA 285 or a condition (e.g., a window head detail) in an assembly known to comply with NFPA 285. The second element requires approval of the analysis by the building official. This approach is often used to evaluate reasonable modifications to an assembly that has already been tested; examples include more robust base walls or different window/fenestration closures.

Commonly referred to as engineering judgements, EJs, or extensions of results, these analyses are the most practical, and commonly used, method used to establish code compliance of wall assemblies required to be tested to, and meet the acceptance criteria, of NFPA 285. The 2023 Edition of NFPA 285 includes a new Annex B Guide for Extensions of Results from Assemblies that Meet NFPA 285. Although the 2024 IBC references an earlier edition of NFPA 285 (the 2019 Edition), the information and guidance provided by Annex B may prove insightful for any party reviewing one of these analyses. NFPA provides free digital access for viewing NFPA standards. Go to nfpa.org for more information on free access to view NFPA 285 and other NFPA standards referenced in the I-Codes.

Each of the compliance methods has its benefits and challenges. For example, while the first method offers the most specific evidence of compliance, one or more NFPA 285 tests for the size of a project or the scope of assemblies in a given project may not be feasible due to the cost and logistics involved in testing. On the other hand, the third method offers flexibility but requires a high level of expertise to help ensure the analysis is accurate and reliable.

Clarification of Height Limitations in Section 1405.1.1

The 2024 IBC revises a code conflict regarding height limitations for combustible exterior wall coverings on buildings of Type I, II, III, and IV construction. A prescribed general height limitation of 40 feet has been clarified for materials and systems such as Metal Composite Materials (MCM) systems and Exterior Insulation and Finish Systems (EIFS) that are on exterior walls subject to provisions requiring those wall assemblies are tested to and comply with NFPA 285.

Section 1405 provides general requirements and limitations for the use of combustible materials on the exterior side of exterior walls. Section 1405.1.1 establishes four limitations to the use of combustible exterior wall coverings on buildings of Type I, II, III, and IV construction. One of these limitations (Item 2) prevents combustible exterior wall coverings on walls greater than 40 feet in height above grade plane. Experienced code users know there are several sections within Chapters 14 and 26 that permit uses over 40 feet based on NFPA 285 testing and compliance. Section 1405.1.1 was revised (revisions in bold text) to correct that conflict:

1. 1405.1.1 Types I, II, III, and IV-HT construction. On buildings of Types I, II, III and IV-HT construction, exterior wall coverings shall be permitted to be constructed of combustible materials, complying with the following limitations:
2. Combustible exterior wall coverings shall be limited to 40 feet (12 192 mm) in height above grade plane.

Exceptions:

1. Metal composite material (MCM) systems complying with Section 1406.
2. Exterior insulation and finish systems (EIFS) complying with Section 1407.
3. High-pressure decorative exterior-grade compact laminate (HPL) systems complying with Section 1408.
4. Exterior wall coverings containing foam plastic insulation complying with Section 2603.[…]

Section 1403 for Materials

Section 1403.8 (2021 IBC) for plastic panels, aprons and spandrel walls was removed from the 2024 IBC. This section, dating back over 20+ years, had become outdated and ineffectual as Chapters 14, 16, 17, and 26 have evolved to contain additional and more specific requirements for uses of plastic materials in exterior walls and wall assemblies.

New Section 1403.14 for insulated vinyl siding was added to the IBC along with the new defined term. Section 1403.14 requires the insulated vinyl siding cladding products are labeled by an approved agency for compliance with the requirements of ASTM D7793.⁴

Section 1407 for Exterior Insulation and Finish Systems (EIFS)

A new Section 1407.5 requires exterior wall assemblies containing EIFS to comply with Section 2603.5. The effect of this new provision is to help ensure the EIFS containing foam plastic insulation complies with the applicable requirements for the use of foam plastic insulation in exterior walls of buildings of all types of construction. Section 2603.5 contains fire safety provisions that include verification of fire-resistance ratings, testing for resistance to radiant ignition, testing for vertical and lateral flame spread, and other requirements.

New Section 1409 for Insulated Metal Panel (IMP) Systems

Recent decades have shown an increase in the understanding and use of Insulated Metal Panel (IMP) systems in building envelope applications. These versatile building products and systems have historically relied on Research Reports and ICC Evaluation Service (ICC-ES) Acceptance Criteria for establishing code compliance because the IBD did not recognize or contain requirements for IMPs as a building product. The new Insulated Metal Panel (IMP) defined term and Section 1409 help ensure differentiation of IMPs from other building products and establishes the minimum requirements for the different types and different uses of IMP products and systems in exterior wall assemblies today, for example:

• Differing requirements applicable to IMP panels with noncombustible core insulation vs. combustible core insulation.
• Differing requirements applicable to IMP systems used as the exterior wall or as an exterior wall covering.
• Differing structural and wind load design requirements based on use.
• Various fire safety provisions, including:
  • Use in exterior walls of Types I, II, III, IV, and V construction.
  • Use in exterior walls required to have a fire-resistance rating.
  • Surface burning characteristics of combustible core insulation.
  • Resistance to ignition and flaming from radiant exposure.
• Labeling

New Section 1411 for Building-integrated Photovoltaic (BIPV) Systems for Exterior Wall Coverings and Fenestrations

New Section 1411 requires BIPV systems used as exterior wall coverings to be listed and labeled in accordance with UL 1703⁵, or both of UL 61730-1⁶ and UL 61730-2⁷ in addition to complying with other applicable provisions of the code.

Photo courtesy of Polyisocyanurate Insulation Manufacturers Association (PIMA)

The roof of a building is an important element of the building envelope. Design, testing, and performance requirements for roof assemblies and roof coverings are different from those for exterior wall assemblies.

IBC CHAPTER 15

Chapter 15 governs roof assemblies and rooftop structures. The roof of a building is an important element of the building envelope. Design, testing, and performance requirements for roof assemblies and roof coverings are different from those for exterior wall assemblies.

Section 1505.1 and Table 1505.1

Section 1505.1 and Table 1505.1 have both received minor adjustments making it clear the required fire classification (i.e., Class A, B, or C) applies to the roof assembly, not strictly the roof covering only. As a reminder, roof assembly fire classification is determined on the basis of testing in accordance with ASTM E108⁸ or UL 790⁹.

Landscaped and Vegetative Roofs

The 2024 IBC includes revisions regarding landscaped and vegetative roofs. The revisions have added a new defined term for landscaped roof and made a minor adjustment to the existing vegetative roof defined term. The inclusion of the new defined term serves to help code users differentiate between the two types of roofs.

The revisions to the defined terms are accompanied by later revisions that incorporate both terms into Section 1505.10 that requires compliance with Sections 1505.1 and 1507.15 for both landscaped and vegetative roofs. The revisions also clarify that vegetative roofs are required to be installed in accordance with ANSI/SPRI VF-1 .

Raised Deck Systems

Section 1511 on rooftop structures includes a significant update in the 2024 IBC. A new subsection 1511.9 and defined term (applicable to Chapter 15 only) have been added regarding raised-deck systems. Raised-deck systems are comprised of a system of decking or pavers that are supported by pedestals and installed over top of a roof assembly. These systems provide a walking surface and are usually installed in relation to occupiable roof (also a new defined term for 2024).

This new Section 1511.9 provides the code users and AHJ’s with important prescriptive guidance for these systems that are seeing increased application and installation on roofs of new and existing buildings. Requirements address the installation and performance requirements ranging from structural and roof drainage requirements to fire safety requirements that address fire classification, fire testing and requirements regarding accessibility and egress.

In terms of fire classification and testing, raised-deck systems are required to be listed and identified with a fire classification in accordance with IBC Section 1505. Further, the identified fire classification is required to be based on testing prescribed in new Sections 1511.9.2.1 or 1511.9.2.2. These two prescribed testing options provide flexibility while helping to ensure fire safety is maintained. The first option, Section 1511.9.2.1, permits the scenario where the raised-deck system and roof assembly are tested and classified separately. Essentially, this option is where a raised-deck system will be installed over top of a roof assembly that is already, or independently, tested and classified as Class A, B, or C. This provision requires that the classification for the raised-deck system is equal to or higher than the roof assembly over which it is intended to be installed. This provision also includes one exception where the decking or pavers of the raised-deck system are of noncombustible materials. In that situation, fire testing of the raised-deck system is not required.

The second scenario, provided by Section 1511.9.2.1, permits the testing of the roof assembly and the raised-deck system together. Use and compliance with this option may prove somewhat more difficult because there is, as yet, limited guidance with regard to how to prepare test specimens that incorporate both a raised-deck system and a roof assembly for testing and classification in accordance with ASTM E108 and UL 790.

Photo courtesy of Huntsman Building Solutions

Foam plastic insulations are widely used in modern buildings due to their excellent thermal performance, versatility, and multi-functional performance attributes.

IBC CHAPTER 26

Section 2603 of the 2024 and earlier editions of the IBC governs the requirements and uses of foam plastic insulation in buildings and structures. Foam plastic insulations are widely used in modern buildings due to their excellent thermal performance, versatility, and multi-functional performance attributes. Assemblies and uses incorporating these materials are also often subject to compliance with other provisions of the code that may or may not refer code users back to Section 2603 or Chapter 26.

Insulating Sheathing

A new Section 2603.1.2 was added to Section 2603 on foam plastic insulation. The new section requires foam plastic insulating sheathing (FPIS) materials to comply with the provisions of Section 2603 and the applicable material standard for Expanded Polystyrene (EPS), Extruded Polystyrene (XPS), or Polyisocyanurate (PIR). This new provision echoes Section 2603.1.1 that requires spray-applied foam plastic insulation to comply with the provisions of Section 2603 and the ICC 1100¹¹ standard.

Applicability of Section 2603.4.1.4 Clarified

Section 2603.4.1.4 is another historical section under Section 2603 on foam plastic insulation. Originally intended to apply to metal-faced panels with foam plastic cores used in exterior walls of storage buildings other than cold storage. Metal-faced panels evolved to become Insulated Metal Panel (IMP) systems. Referenced in exceptions to Section 2603.5.2 thermal barrier, 2603.5.4 potential heat, 2603.5.5 vertical and lateral flame propagation, Section 2603.4.1.4 began to be used to justify broad exemptions for non-IMP exterior wall coverings and systems from these important fire safety requirements, therefore, the provision was changed to explicitly reference IMP systems with foam plastic insulation cores, clarifying the applicability of the section. This clarification is important because it helps ensure the proper application of the code provision generally, but also to ensure the provision is not misused to get around important fire performance tests materials and assemblies that support fire safety of exterior wall assemblies containing foam plastics.

Section 2603.9 Special Approval Limited

Section 2603.9 for the special approval of uses of foam plastic is now limited to one of the four large-scale tests identified. Previously, these four tests were referenced as examples of large-scale tests suitable for the evaluation and qualification of assemblies using foam plastic to not have to comply with the requirements of either Section 2603.4 or Section 2603.6. Despite the new limitation, test specimen assemblies are still required to include typical installation details and to be tested in the manner intended for use.

Photo courtesy of Shutterstock. Credit: Eakrin Rasadonyindee

For building and construction professionals, understanding the 2024 IBC updates is essential for navigating the intersection of the complexities of contemporary design and construction with their project conditions to help ensure code compliance and the highest minimum level of fire safety.

International Residential Code® (IBC) Updates

The 2024 Edition of the International Residential Code® (IBC®) does not contain as many updates as the IBC to provisions for fire safety of exterior wall assemblies, exterior wall coverings, claddings, and uses of foam plastic insulation. One of the most significant changes is the reorganization of Chapter 3 that relocates provisions for foam plastics to Section R303.

Chapter 3 Building Planning

The 2024 IRC Chapter 3 is completely reorganized and restructured from the 2021 Edition. For example, what was Section R316 Foam Plastics in the 2021 Edition is now Section R303 for the 2024 Edition.

There are no significant new provisions or updates to provisions under Section R302 on fire-resistant construction regarding exterior walls, wall coverings, or foam plastics. There were some revisions, however, focused on improving clarity around dwelling units and how to determine fire separation distances in context of adjacent townhouses, between different dwelling units within townhomes, as well as opening protections and penetrations in the rated assemblies separating these dwelling units.

Section R303 on foam plastics does, however, include some revisions. New Sections R303.1.1 and R303.1.2 require foam plastics to comply with the requirements of Section R303 and one of several material standards, as applicable, to spray-applied foam plastic (Section R303.1.1) and foam plastic insulating sheathing composed of expanded polystyrene (EPS), extruded polystyrene (XPS), or polyisocyanurate (PIR) (Section R303.1.2). These revisions reflect similar revisions to IBC Section 2603 over the last two code development cycles.

Section R303.6 Specific approval was revised, similarly to IBC Section 2603.9, to limit qualification tests to only the four referenced large-scale tests identified and that test specimens must reflect the actual end-use configuration.

In Summary

The 2024 IBC includes many useful changes, updates, and new content regarding combustible exterior wall assemblies, combustible exterior wall coverings, roof assemblies, and foam plastic insulation and its uses in the different elements of the building envelope. The changes help code users by improving the clarity of requirements (including interrelated requirements across different chapters and sections), by improving and clarifying terminology, and by both adding needed content for current products and practices while removing outdated content that has lost its usefulness. For building and construction professionals, understanding these updates is essential for navigating the intersection of the complexities of contemporary design and construction with their project conditions to help ensure code compliance and the highest minimum level of fire safety.

With the 2024-2026 Code Development Cycle underway, we can expect that the 2027 Edition of the IBC will continue to build on experience with both traditional and innovative materials, designs, and practice to make buildings safer and more sustainable for the future.

References

¹International Code Council, Inc. 2024 International Building Code, (2024 IBC), First Printing August 2023, https://codes.iccsafe.org/content/IBC2024P1/.
²National Fire Protection Association (NFPA). NFPA 285 (2023), Standard Fire Test Method for Evaluation of Fire Propagation Characteristics of Exterior Wall Assemblies Containing Combustible Components, Issued August 2022, https://www.nfpa.org/codes-and-standards/nfpa-285-standard- development/285/.
³International Code Council, Inc., 2024 International Code Council Performance Code for Buildings and Facilities, (2024 ICCPC), First Printing August 2023, https://codes.iccsafe.org/content/ ICCPC2024P1/.
⁴ASTM International, D7793-20 Standard Specification for Insulated Vinyl Siding, Published November 2020, https://astm.org/.
⁵UL Standards & Engagement Inc., UL 1703 Standard for Flat-plate Photovoltaic Modules and Panels— with Revisions through November 2019, November 2019, https://shopulstandards.com/.
⁶UL Standards & Engagement Inc., UL 61730-1 Standard for Photovoltaic (PV) Module Safety Qualification — Part 1: Requirements for Construction—with Revisions through April 2020, April 2020, https://shopulstandards.com/.
⁷UL Standards & Engagement Inc., UL 61730-2 Standard for Photovoltaic (PV) Module Safety Qualification — Part 2: Requirements for Testing—with Revisions through April 2020, April 2020, https:// shopulstandards.com/.
⁸ASTM International, E108-20a Standard Test Methods for Fire Tests of Roof Coverings, Published November 2020, https://astm.org/.
⁹UL Standards & Engagement Inc., UL 790 Standard Test Methods for Fire Tests of Roof Coverings— with Revisions through October 2018, October 2018, https://shopulstandards.com/.
¹⁰Single Ply Roofing Industry, ANSI/SPRI VF-1-2023 External Fire Design Standard for Vegetative Roofs, Published April 2023, https://www.spri.org/.
¹¹International Code Council, Inc., ICC 1100 Standard for Spray-applied Polyurethane Foam Plastic Insulation, First Printing December 2019, https://shop.iccsafe.org/standards.html/.
¹²International Code Council, Inc. 2024 International Residential Code, (2024 IRC), Version 1.0 (digital): January 2024, https://codes.iccsafe.org/content/IRC2024P2/.

Eric W. Banks is a technical consultant with 20+ years’ experience with building envelope insulation products with an emphasis on foam plastics. www.linkedin.com/in/eric-banks-422241a/