SBCA Conducts Fire Testing to Protect CM’s Market Share
Editor's Note: The following article was originally published as a CM-Member Only story on April 2, 2015, and is now being republished with minor edits for the general public.
During the first two weeks of March, SBCA conducted a series of ASTM E119 standardized floor assembly fire tests at the NGC Laboratories testing facility in Buffalo, NY. These tests were conducted to gather empirical data in an apples-to-apples comparison of unprotected floor assemblies built from 2x10s, floor trusses without splice plates, floor trusses with splice plates and I-joists. The goal of this testing was to have original test data that conforms precisely to the requirements of ASTM E119, which requires the structural elements resisting fire to have one element in the design at 100% of its allowable design stress. ASTM does this so that accurate benchmark comparisons can be made between different products or materials.
UL recently conducted targeted ASTM E119 testing as well, and this full design load testing yielded results that can be seen in the slide below from a presentation given by Mr. Sean DeCrane, Battalion Chief and Director of Training for the Cleveland Department of Public Safety's Division of Fire, during an Ohio Residential Advisory Committee Meeting in the summer of 2014.
The data from SBCA’s E119 tests follow:
This data confirms the UL data highlighted in yellow on the slide. This means SBCA now has the best benchmark data on unprotected fire endurance performance available. SBCA is now advocating sound science and accuracy with respect to unprotected floor assembly fire performance. SBCA is advocating that empirical test data needs to be applied in a fair manner if the code compliance goal is as the code states:
The purpose of this code is to establish minimum requirements to safeguard the public safety, health and general welfare through affordability, structural strength, means of egress facilities, stability, sanitation, light and ventilation, energy conservation and safety to life and property from fire and other hazards attributed to the built environment and to provide safety to fire fighters and emergency responders during emergency operations.
The American Wood Council (AWC) and National Association of Homebuilders (NAHB), through developing and advocating for R501.3, have established that the minimum expected fire performance of a floor assembly is at least 15 minutes using the code reference standard floor assembly fire endurance performance test – ASTM E119. Further, under R501.3 there is now the stated expectation in the building code that under fire conditions, an unprotected floor assembly constructed of 2x10s performs equal to or greater than a protected floor assembly with a ½” regular gypsum wallboard membrane affixed to, for example, the underside of floor trusses or I-joists.
In IBC Table 722.6.2(1), “Time Assigned to Wallboard Membranes,” the expected fire performance of ½” regular gypsum wallboard is 15 minutes based on traditional ASTM E119 tests. As a consequence, the code assumes 2x10s must perform equal to or better than 15 minutes plus the fire performance of, for example, floor trusses or I-joists. This is an assumption with significant risk to all fire fighters, particularly if 2x10s do not provide an actual 15 minutes of performance under the only standard testing conditions that the building code has adopted (ASTM E119) as they can justifiably expect they should. UL suggests that the proper number is 26 minutes of performance using ASTM E119 testing.
It creates an even broader risk if 2x10s do not perform to a level that the code under R501.3, and therefore law, demands. In particular because the code is there to “establish minimum requirements to safeguard the public safety…..and to provide safety to fire fighters and emergency responders during emergency operations.”
Based on information already in the public domain, unprotected (non-compartmentalized) ASTM E119 fire endurance testing of 2x10s, wood I-joists, wood trusses, and cold-formed steel joists and trusses all last less than 10 minutes under fire conditions. The details of historical performance and recommendations for improving performance can be found on the National Fire Protection Association’s (NFPA) website in the 1992 National Fire Protection Research Foundation Technical Report entitled, “National Engineered Lightweight Construction Fire Research Project.”
A more recent example is a 2012 report published by the Underwriters Laboratory entitled, “Improving Fire Safety by Understanding the Performance of Engineered Floor Systems and Providing the Fire Service with Information for Tactical Decision Making.” Please see highlighted items on pages 3, 4, 15-17, 23-24, 33, 39-40, 64-70 for detailed opinions by UL. This same information is included in a 2012 report published by the Underwriters Laboratory entitled, “NIST ARRA Appendix C - Full-Scale Floor System Field and Laboratory Fire Experiments.”
Therefore, SBCA’s primary goal in sharing this data will be to convince the code officials, policy makers and builders that code provisions like IRC’s R501.3, which requires the application of gypsum to unprotected floor assemblies unless they are constructed of 2x10s, are not only unfounded but are likely detrimental to the fire service and the public.
The secondary goal of the SBCA’s ASTM E119 testing is to use this data to build stronger lines of communication between the components industry and the fire service by erasing misconceptions about the actual fire performance of wood components and encouraging collaborative approaches (smoke detectors, universal gypsum applications, sprinklers, etc.) rather than the typical demonization of componentized framing that has taken place, which does not foster positive collaboration.
Both of these goals of the testing are based on the desire to restore a level playing field for all floor assembly products within the building code and allow floor trusses and I-joists to once again compete on their own merits in the market.
The testing has been completed, and it confirms the UL position stated in the last two sentences of their conclusion: