LinkedIn Youtube Facebook Twitter Sales Rep Locator Document Search

NFPA 285: Preventing the Spread of Fire in Multi-Story Buildings

Established by the National Fire Protection Association, NFPA 285 is a method for testing the rate of fire spread within vertical wall assemblies in multistory commercial buildings. The NFPA 285 test was developed to help builders and owners reduce the potential for the upward spread of fire, should disaster strike.

NFPA 285 is becoming increasingly necessary due to the increasing use of products that boost a building’s energy efficiency. While new cladding materials, insulation, and weather barriers have been proven to cut a building’s energy consumption and lifecycle costs, they are also combustible components.

Once such components are within wall assemblies, they present specific fire risks for non-load-bearing exterior walls in multistory buildings, as these assemblies allow air to move freely through wall cavities. Accordingly, code compliance now includes wall assemblies with combustible cladding materials, insulation and weather barriers if they are installed on non-combustible construction types I-V.

Henry Company offers one of the industry’s broadest lines of Commercial Air Barrier products that have been tested and pass NFPA 285 in various wall assemblies.

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.

NFPA 285 and Henry Commercial Air Barrier Systems

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

Continuing Education Unit on NFPA 285

Download PDF Does My Wall Assembly Have to Comply with NFPA 285?

Technical sheet detailing Henry’s NFPA 285-compliant products

Download PDF TechTalk_Henry_AB_NFPA285_Assembly.pdf