Firefighter Deaths Underscore Importance of SBCA's RB69 Code Change Proposal
Editor’s Note: SBCA continues to believe that all floor systems should be protected with ½” gypsum wallboard membrane. SBCA has proposed an IRC code change proposal (RB69-16) that will be heard at the upcoming October code development hearing in Kansas City, Missouri.
BillyG, author of firefighterclosecalls.com's "Secret List," is known for providing in-depth updates on notable firefighter events. He recently reported on a fire in Wilmington, Delaware, where two firefighters were killed. Here are key concepts he reported with respect to this tragedy:
2 Firefighters died in a floor collapse at row house (i.e. townhouse) fire that was built in 1944. 2 remain in critical condition. Wilmington's Fire Chief Anthony Goode said the floors in the home were soft and brittle. The fire was reported 2:54 a.m. at 1927 Lakeview Road, in a neighborhood of brick rowhouses about a block south of South Union Street. Firefighters arrived to find flames shooting out of windows and doorways. Fire Department Battalion Chief James Jobes said firefighters were working on the first floor when it collapsed, trapping them in the basement. According to the Fire Department, one or more firefighters became trapped at 3:14 a.m. and radioed for help. When the floor caved, veteran firefighters Christopher Leach and Jerry Fickes were among the "four or five" firefighters who fell into the basement and became trapped.
of SBCA’s RB69 proposal to improve firefighter safety, and life safety overall.
The American Wood Council (AWC) has published the following with regard to the R302.13 code change authored by the National Association of Homebuilders (NAHB) and AWC, which requires everything other than conventionally-framed floors to be protected with a layer of ½” of gypsum wallboard (emphasis added):
Chapter 3 of the International Residential Code (IRC) sets forth minimum requirements for the health, safety, and welfare of occupants in one- and two-family dwellings and townhouses. Section R302.13 provides for the minimum fire protection of floors that do not require a fire resistance rating. During the development of these provisions in the 2012 model code, historical precedent and the familiarity of the fire service with the attributes of solid sawn framing lumber led to choosing solid sawn lumber joists not less in size than 2"x10" as the benchmark for fire performance of wood floor assemblies [...]. The code requires other floor systems to be protected by a minimum of one-half inch (1/2") layer of gypsum wallboard, five-eighths inch (5/8") wood structural panels, or equivalent [...]. For more information, see the FAQ and white paper available here.
Testing data published in the UL Report “Improving Fire Safety by Understanding the Fire Performance of Engineered Floor Systems and Providing the Fire Service with Information for Tactical Decision Making” showed unprotected 2x10 floor assembly performance was 7 minutes and four seconds when tested under standard ASTM E119 100% design load conditions.
UL also tested legacy 2x8 dimension lumber at 100% design load and found the time to failure to be 14 minutes 20 seconds. It is important to note that UL followed the complete ASTM standard testing protocol. Page 24 of the UL Report provides details of the benchmark testing and comparisons. This is what AWC is referring to above as historical precedent, but recent testing and real-world experiences suggest basing decisions on historical precedent and legacy information may be placing firefighters at serious risk.
As noted above in BillyG’s report, Wilmington Fire Chief Anthony Goode said the floors in the home had become soft and brittle. The following video and photos provide a good illustration of what soft and brittle looks like during a test of a 2x10 floor system under ASTM E119 100% design load conditions:
Video 1: An overview of the unprotected 2x10 ASTM E119 100% design load fire endurance testing.
Photo 1: NGC Testing of a 2x10 floor system that failed at 10 minutes 37 seconds
Photo 2: NGC Testing of a 2x10 after removing the water containers that loaded the assembly to 100% design load.
Photo 3: NGC Testing of a 2x10 after lifting the assembly off the furnace.
Conversely, soft and brittle would not be used to describe the fire endurance performance of metal plate connected wood trusses. The following video and photos show a floor truss system subjected to the same ASTM E119 100% design load test. The floor truss performance could best be described as ductile compared to the 2x10 total collapse:
Video 2: An overview of the unprotected metal plate connected wood truss 100% design load fire endurance testing.
Photo 4: NGC Testing of a metal plate connected wood truss floor system that failed at 6 minutes 54 seconds
Photo 5: NGC Testing of a metal plate connected wood truss floor system after removing the water containers and spraying down the trusses with a fire hose.
Photo 6: NGC Testing of a metal plate connected wood truss floor system after the fire test and after the fire was put out with a fire hose.
Photo 7: NGC Testing of a metal plate connected wood truss floor system after the fire test and after the fire was put out with a fire hose.
Clearly 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.
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.
SBCA hopes the tragic fire in Wilmington, Delaware is a wakeup call for all in attendance at the ICC code hearings in Kansas City, Missouri later this month. The loss of life underscores the serious nature of this issue, and SBCA urges the congregation of building officials to OVERTURN THE IRC COMMITTEE and vote in favor of SBCA’s RB69 proposal to improve firefighter safety, and life safety overall.
For more information on the fire performance of floor systems, click here. SBCA continues to believe that all floor systems should be protected with ½” gypsum wallboard membrane. If no protection is required for a particular floor system by the code, that floor system should be tested to ensure it is in accordance with ASTM E119 at 100% design load to generate a 26-minute performance as defined in UL’s report. Beyond this approach, to achieve greater fire safety in single-family homes, SBCA advocates for the use of sprinkler systems that are becoming increasingly more affordable.