At Building Enclosure, it’s our goal to provide you with the latest standards and building codes in the industry. I’ve come across a few questions and comments lately on NFPA 285 and felt like it was a good topic to address within our current issue. NFPA 285: Standard Fire Test Method for Evaluation of Fire Propagation Characteristics of Exterior Non-Load-Bearing Wall Assemblies Containing Combustible Components on the National Fire Protection Association’s website is stated as this:
“This standard provides a standardized fire test procedure for evaluating the suitability of exterior, non-load bearing wall assemblies and panels used as components of curtain wall assemblies that are constructed using combustible materials or that incorporate combustible components for installation on buildings where the exterior walls are required to be non-combustible.”
What Do All Those Words Mean?
Well, it’s important to first recognize that this standard requires both visual observations made by those in the laboratories actually conducting these tests, along with the temperature data recorded during said testing.
NFPA 285 is required in the International Building Code when foam plastic insulation is used in exterior walls. The certain construction types that this pertains to (I, II, III or IV), by the code definition, have exterior walls constructed of non-combustible materials.
The standard’s purpose is to determine that combustible foam plastic insulation, when exposed to fire on the exterior, does not spread inside or over the surface of the wall assembly. To pass the test, the wall assembly must prove limited spread of fire. The extent of the fire is determined visually, measured in feet and by temperature (thermocouples are placed throughout the wall assembly to collect the data).
A more in-depth look at NFPA 285 can also be found in our recent article, “The Evolution of Continuous Insulation” (Building Enclosure, Fall 2016).
Stay up-to-date on the latest in our industry. For codes, details and other educational materials, visit our website’s technical section, or turn to page 8 in this issue.