Exterior Walls – NFPA 285 Compliance

What is NFPA 285?

NFPA 285 is a standard test method published by the National Fire Protection Association for evaluating the fire propagation characteristics of exterior non-load bearing wall assemblies with combustible components. The test method was established recognizing that such walls contain combustible components and evaluates how readily and quickly the exterior wall promotes fire spread.

As part of the 9th Edition of 780 CMR, MA State Building Code, the 2012 Edition of NFPA 285 is adopted.

Note that NFPA 285 is an assembly test, and not a component test. This means that the entire exterior wall assembly must be evaluated for compliance, not single materials or components located within an assembly.

When is compliance with NFPA 285 required?

Compliance with the requirements of NFPA 285 is required for an exterior wall assembly under the following conditions. Note that MA amends several of these sections, so using the MA Amendments in conjunction with the base IBC is necessary for projects located within the Commonwealth.

  • Air/Vapor Barriers – Exterior walls in buildings with Type I, II, III, or IV construction more than 40 feet in height that contain a combustible water-resistive barrier are required to comply with NFPA 285. Exceptions to this requirement:
    • Walls in which the water-resistive barrier is the only combustible component, and the exterior wall has a covering of brick, concrete, stone, terra cotta, stucco, or steel per 780 CMR Table 1405.2; or
    • Walls in which the water-resistive barrier is the only combustible component and the water-resistive barrier meets certain material properties including peak heat release rate, total heat release, flame spread index and smoke-developed index.
  • MCM Panels – Metal Composite Materials (MCM) in exterior walls in buildings with Type I, II, III, or IV construction are required to comply with NFPA 285. Various exceptions are provided, including:
    • Installations up to 40 feet in height, where the fire-separation distance exceeds 5 feet, or the area of MCM is less than 10% of the wall surface;
    • Installations up to 50 feet in height, where the MCM has a limited self-ignition temperature, and is limited in the total installed area; or
    • Installations up to 75 feet in height (or beyond if fully sprinkler protected) based on the building occupancy, fire separation distance, area limitation of MCM, and material properties (i.e. self-ignition temperature) of the MCM.
  • HPLs – High-Pressure Laminates (HPL) in exterior walls in buildings with Type I, II, III, or IV construction are required to comply with NPFA 285. Various exceptions are provided, including:
    • Installations up to 40 feet in height, where the fire-separation distance exceeds 5 feet, or the area of MCM is less than 10% Of the wall surface; or
    • Installations up to 50 feet in height, where the MCM has a limited self-ignition temperature, and is limited in the total installed area
  • Mechanical Equipment Screens – Compliance with NFPA 285 is an option for compliance for combustible mechanical equipment screens
  • Foam Plastic Insulation – Foam plastic insulation in exterior walls in buildings with Type I, II, III, or IV construction are required to comply with NFPA 285. Exceptions include:
    • Special approval based on large-scale tests such as NFPA 286, FM 4880, UL 1040, or UL 1715.
    • Wall assemblies where the insulation is covered on each face by 1-inch thick masonry, concrete, terracotta, stucco, or 0.5-inch thick Type X gypsum board. In most cases, there must be no airspace between the insulation and the exterior wall covering;
    • Low-rise buildings that are sprinklered in accordance with NFPA 13 where a fire flow analysis has been performed without sprinkler decrease allowance that shows adequate water is available.

Questions on NFPA 285 scoping language and options for compliance? Feel free to reach out to us to find out more.