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The 2024 edition of the International Residential Code (IRC) introduces several key revisions to Section R902.1, which addresses fire classification requirements for roof assemblies. These updates clarify terminology and enhance the logical structure of the provisions without imposing additional construction costs. Below, we'll explore the specific changes made from the 2021 IRC and the rationale behind these updates.
2021 IRC:
2024 IRC:
Reasoning:This change was implemented to accurately reflect that fire classification applies to entire roof assemblies, not just the roofing materials. Roof assemblies encompass all components, including underlayment, insulation, and structural elements, which contribute to the fire resistance of the roof system.
2021 IRC:
2024 IRC:
Reasoning:This clarification helps ensure compliance and uniform enforcement by emphasizing the necessity for third-party verification of fire classification.
2021 IRC:
2024 IRC:
Reasoning:Reordering the provisions provides a more intuitive and streamlined understanding of the compliance process for building officials, contractors, and designers.
The proposal for these changes explicitly stated that there would be no impact on construction costs, as the modifications are limited to language improvements and structural clarifications.
The exceptions in both the 2021 and 2024 versions remain substantively the same, with only minor wording refinements:
The revisions to Section R902.1 were proposed by Aaron Phillips of the Asphalt Roofing Manufacturers Association (ARMA) under proposal RB251-22. The committee accepted the changes as submitted, with a vote of 6-4 in favor, recognizing the need for clearer language and improved code usability.
The final approval of these revisions demonstrates the ongoing efforts to enhance code clarity and applicability without introducing unnecessary complexities or cost burdens to the construction industry.
The 2024 IRC revisions to Section R902.1 represent a meaningful improvement in code clarity and enforceability. By refining terminology and restructuring the provisions logically, these changes provide better guidance for ensuring fire safety in residential roofing systems. Builders, inspectors, and designers should take note of these updates to ensure compliance with the latest standards and best practices in roof fire classification.
Key Changes from the 2021 IRC to the 2024 IRC
1. Terminology Adjustment: From "Roofing" to "Roof Assemblies"
2021 IRC:
- The term "roofing" was used to describe the materials covering the roof structure.
2024 IRC:
- The revised code replaces "roofing" with "roof assemblies."
Reasoning:This change was implemented to accurately reflect that fire classification applies to entire roof assemblies, not just the roofing materials. Roof assemblies encompass all components, including underlayment, insulation, and structural elements, which contribute to the fire resistance of the roof system.
2. Clarification of Fire Classification Requirements
2021 IRC:
- The section stipulated that Class A, B, or C roofing must be installed in jurisdictions requiring their use or when the roof edge is within 3 feet of a lot line.
2024 IRC:
- The updated section maintains these requirements but adds further clarification by specifying that when Class A, B, or C roof assemblies are required, they must be listed and identified by an approved testing agency.
Reasoning:This clarification helps ensure compliance and uniform enforcement by emphasizing the necessity for third-party verification of fire classification.
3. Improved Logical Flow
2021 IRC:
- The order of provisions could lead to potential confusion regarding when testing and listing requirements apply.
2024 IRC:
- The revised language follows a clearer sequence, first establishing when fire classification is required, then specifying the testing standards (ASTM E108 or UL 790), and finally addressing listing and identification requirements.
Reasoning:Reordering the provisions provides a more intuitive and streamlined understanding of the compliance process for building officials, contractors, and designers.
4. No Increase in Construction Costs
The proposal for these changes explicitly stated that there would be no impact on construction costs, as the modifications are limited to language improvements and structural clarifications.
Updated Exception Wording
The exceptions in both the 2021 and 2024 versions remain substantively the same, with only minor wording refinements:
- Brick, masonry, and exposed concrete roof decks are considered Class A roof assemblies.
- Ferrous or copper shingles, metal sheets, clay or concrete tiles, and slate installed on noncombustible decks are Class A roof assemblies.
- Minimum 16-ounce copper sheets over combustible decks qualify as Class A roof assemblies.
- Slate installed over underlayment over combustible decks qualifies as a Class A roof assembly.
The Code Change Process
The revisions to Section R902.1 were proposed by Aaron Phillips of the Asphalt Roofing Manufacturers Association (ARMA) under proposal RB251-22. The committee accepted the changes as submitted, with a vote of 6-4 in favor, recognizing the need for clearer language and improved code usability.
The final approval of these revisions demonstrates the ongoing efforts to enhance code clarity and applicability without introducing unnecessary complexities or cost burdens to the construction industry.
TBCF Summary
The 2024 IRC revisions to Section R902.1 represent a meaningful improvement in code clarity and enforceability. By refining terminology and restructuring the provisions logically, these changes provide better guidance for ensuring fire safety in residential roofing systems. Builders, inspectors, and designers should take note of these updates to ensure compliance with the latest standards and best practices in roof fire classification.