7 Reasons to Immediately Delete Exception 4 from R501.3

Originally published by the following source: SBCAJanuary 19, 2016

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Summary

Recent ASTM E119 testing (using 100% design load conditions as required by that standard), conducted independently by Underwriters Laboratory (UL) and NGC Testing Services (NGC), confirm that an unprotected floor assembly constructed of 2x10s or Flak Jacket coated I-joists do not provide “equivalent performance” to a floor assembly that has a ½” gypsum wallboard membrane ceiling as prescribed by IRC-12 R501.3 and IRC-15 R302.13. Standardized E119 testing shows all unprotected structural floor assemblies perform for far less than the 15-minute membrane time provided by a ½” gypsum wallboard membrane ceiling, as defined by code (IBC-12 Section 722.6.2).

UL concludes on page 67 of its test report, “There are little if any warning signs of collapse so it is very important to understand the hazards associated with a basement fire because the consequences of falling through a floor into a basement fire are pinnacle.” Further, on page 66, the UL test report concludes, “This [the fire service response time scenario] assumes ….. the fire department begins their firefighting operation in 8 minutes…. This emphasizes the importance of protecting all types of flooring systems, including dimensional lumber.” (emphasis added.)

A failure to eliminate Exception 4 from IRC-12 R501.3 and IRC-15 R302.13 could lead to a firefighter falling through an unprotected 2x10 or Flak Jacket coated I-joist floor and being maimed or killed due to an erroneous assumption the system adheres to the traditional “20-minute rule.” In contrast, by providing a ½” gypsum wallboard membrane ceiling to all floor systems, 20 minutes of actual performance time is likely to be present.

In general, the law states the purpose of a building code (See R101.3 Intent), “is to establish minimum requirements to safeguard the public safety, health, and general welfare…..and to provide safety to firefighters and emergency responders during emergency operations.”

Seven Reasons to Immediately Delete Exception 4 from IRC-12 R501.3 and IRC-15 R302.13

1. Underwriters Laboratory (UL) testing found unprotected 2x10 floor assembly performance was 7:04 minutes when tested under full design load ASTM E119 standardized conditions. It is important to note that UL followed the complete ASTM standard testing protocol. Page 24 of the UL test report entitled, Improving Fire Safety by Understanding the Fire Performance of Engineered Floor Systems and Providing the Fire Service with Information for Tactical Decision Making, provides details of the benchmark testing and comparisons made.

2. (UL) states definitively that it is import to protect “all types of flooring systems, including dimensional lumber.”

  • UL echoes the intent of the law on page 3 of their test report, stating, “The main objective of this study was to improve firefighter safety by increasing the level of knowledge on the response of residential flooring systems to fire. Several types (or series) of experiments were conducted and analyzed to expand the body of knowledge on the impact of fire on residential flooring systems.”
  • UL concludes on page 66 of their test report that basement floor assembly fires are a challenge to the fire service where, “This [the fire service response time scenario] assumes that the fire is witnessed, called into the fire department, the fire department is dispatched, the fire department arrives and the fire department begins their firefighting operation in 8 minutes. While possible, this is not the case for the majority of fires that occur across the United States. This emphasizes the importance of protecting all types of flooring systems, including dimensional lumber.” (emphasis added.)
  • UL states on page 67 of their test report, “There are little if any warning signs of collapse so it is very important to understand the hazards associated with a basement fire because the consequences of falling through a floor into a basement fire are pinnacle.”
  • UL concludes on page 69 of their test report, “This research study provides data to substantiate the need to protect dimensional lumber floor systems to improve firefighter safety.” (emphasis added.)

3. The Structural Building Components Association (SBCA) recently undertook testing at NGC Testing Services (NGC), an International Accreditation Service (ICC-IAS) accredited ISO/IEC 17025 ASTM E119 fire testing facility. SBCA chose to test at NGC versus UL so the SBCA ASTM E119 test procedure and resulting test data would be an independent assessment of floor assembly performance. SBCA testing found unprotected 2x10 floor assembly performance was 10:35 minutes. This result confirms the UL testing result. (see table below).

4. Given the UL test report has been readily available since 2012, and its results have been confirmed by 2015 testing conducted at NGC, it is clear that IRC-12 R501.3 and IRC-15 R302.13 should be immediately amended to eliminate Exception 4: Wood floor assemblies using dimension lumber or structural composite lumber equal to or greater than 2-inch by 10-inch (50.8 mm by 254 mm) nominal dimension, or other approved floor assemblies demonstrating equivalent fire performance. The law requires establishing “minimum requirements to safeguard the public safety, health, and general welfare..…and to provide safety to firefighters…”  

5. A failure to eliminate Exception 4 from IRC-12 R501.3 and IRC-15 R302.13 could lead to a firefighter falling through an unprotected 2x10 or Flak Jacket coated I-joist floor and being maimed or killed due to an erroneous assumption the system adheres to the traditional “20-minute performance rule.” In contrast, by providing a ½” gypsum wallboard membrane ceiling to all floor systems, 20 minutes of actual performance time is likely to be present.

6. In general, the law protects free market competition for the benefit of the public. Exception 4 of IRC-12 R501.3 and IRC-15 R302.13 does exactly the opposite by constraining competition. When overall cost is the driver for which floor system a builder installs, a 2x10 floor assembly without the need for applying a ½” gypsum wallboard membrane will be a cost-preferred solution over any other floor assembly where purchasing and installing a ½” gypsum wallboard membrane is required.

7. Exception 4 of IRC-12 R501.3 and IRC-15 R302.13 establishes an artificial market preference for 2x10s (as well as products like Flak Jacket coated I-joists) because they do not reach a 15 minute level of performance. ICC Evaluation Service (ICC-ES) developed an “acceptance criteria” that allows a non-standard ASTM E119 design load test (at 50% of design load) to be used to deem products “equivalent to 2x10s in performance.” This is a non-standardized approach, which has no basis in the building code; is not based on standardized ASTM E119 testing; and, creates potential life safety risks, market confusion, and market inequities.