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.

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.

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.

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/