NFPA 285 and Henry Commercial Air Barrier Systems
Established by the National Fire Protection Association, NFPA 285 is a method for evaluating fire propagation characteristics of exterior wall assemblies greater than 40’ tall. The NFPA 285 test was developed to help builders and owners reduce the potential for fire spread, should disaster strike.
NFPA 285 compliant wall assemblies are becoming increasingly necessary due to the high demand for energy efficient buildings. While insulation and weather barriers have proven to reduce building energy consumption and lifecycle costs, their combustibility may increase fire risk.
Adding these combustible components within exterior wall assemblies presents specific fire risks for non-load-bearing exterior walls in multistory buildings, as these assemblies allow air to move freely through wall cavities. Accordingly, the International Building Code has extended NFPA 285 compliance requirements to all construction types (I-V) where combustible components, such as cladding materials, insulation and weather barriers, are installed on non-combustible exterior wall assemblies.
Henry offers three Commercial Air Barriers that meet the minimum requirements for exception #2 as defined in the 2018 IBC Section 1402.5, meaning, when the water-resistive barrier is the only combustible component in the wall assembly, designing with these three Henry air barriers does not trigger the requirement for NFPA 285.
Henry Company offers one of the industry’s broadest lines of Commercial Air Barrier products for use in various NFPA 285 compliant wall assemblies.
Learn More About NFPA 285
Wall assembly components installed to effectively resist air leakage An air barrier should be considered a SYSTEM not a product
Water-resistive barrier (WRB)
Product designed to repel water and protect sheathing and framing
A thermal resistant product installed continuously over a building envelope to eliminate thermal bridging
National Fire and Protection Association (NFPA)
Trade association that creates and maintains standards and codes for usage and adoption by local governments
Authority Having Jurisdiction (AHJ)
Building and/or fire official of the city or county where the project is located
2018 IBC Section 1402.5 – Exception #2
When the WRB is the only combustible component in your wall assembly, the code states that if the WRB has a peak heat release rate of less than 150 kW/m2, a total heat release of less than 20 MJ/m2 and an effective heat of combustion of less than 18 MJ/kg as determined in accordance with ASTM E1354 and has a flame spread index of 25 or less and a smoke developed index of 450 or less as determined in accordance with ASTM E84 or UL 73, then the WRB is not a trigger for NFPA 285 compliance.
Henry air barriers that help you design in this manner are:
The NFPA 285 test: 30 minutes of flame
NFPA 285 testing ultimately attempts to identify wall assemblies which limit the spread of interior fires to other floors or adjacent areas in multistory buildings. It is an assembly test that requires the construction of a two-story apparatus in a testing facility, then a monitored burn of the assembly for 30 minutes.
The test scenario is a flashover fire – in this case, one started by a gas-fired burner on the interior of the wall test assembly. This interior fire source burns until it ignites a second gas-fired burner positioned near a replicated window opening. Once it does, the test focuses on flame propagation in key areas:
- Exterior wall assembly surface
- Vertically within combustible components from one story to the next
- Over the interior wall assembly surface from one story to the next
- Laterally from fire origin to adjacent compartments or spaces
If the wall assembly stays within acceptable flame spread and temperature limits for 30 minutes, it passes the test. Passing wall assemblies must be built as tested on site, as any modifications to the passing assembly void an authorized ruling.
See how Henry takes the heat
Watch a time-lapsed video of our NFPA 285 test from build to burn to cool-down.
Henry Air Barriers that meet IBC NFPA 285 Exceptions
Find out more about Henry and NFPA 285
Download from the pdfs compiled below to learn more. For specific questions about NFPA 285 and Henry’s NFPA-compliant air barrier products, contact Henry at 1-800-486-1278 or [email protected].
Continuing Education Unit on NFPA 285
Technical sheet detailing Henry’s NFPA 285-compliant products
NFPA 285 Flow Chart
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