The NFPA 285 standard is a test method used primarily in the United States to evaluate the flammability characteristics of exterior wall assemblies containing combustible components.
When a wall assembly meets the requirements of NFPA 285, it means that it has passed specific fire tests that assess its ability to resist flame propagation in a multi-story building facade.
Here are the key aspects of NFPA 285 testing procedure:
1. Fire Propagation Control:
The standard tests how wall assemblies limit the spread of fire within the wall and to other parts of the building via the exterior. It checks for vertical and lateral flame spread beyond a certain height and distance from the origin of the fire.
2. Test Setup and Execution:
The test involves simulating a fire in a two-story test structure with the wall assembly in question installed as the exterior facade. A fire source is placed inside a room at the first floor level, and observations are made to see how the fire spreads vertically to higher levels or laterally.
3. Criteria for Passing:
To meet the requirements, the wall assembly must prevent fire from spreading to more than 10 feet above the top of the window on the first floor and no more than 5 feet laterally from the centerline of the window. Also, the interior of the wall assembly should not contribute significantly to fire growth or spread.
Application in Building Design:
Compliance with NFPA 285 is essential for ensuring the safety of buildings, particularly those with multiple stories and those that use materials that might be considered combustible. It’s often a requirement for buildings that fall under certain building codes, especially when combustible materials are used in the facade.
Meeting NFPA 285 requirements is crucial for building safety in preventing fire spread, ensuring that materials and design choices contribute to the overall fire safety strategy of a structure.
A joint research project has been recently undertaken by the National Ready Mixed Concrete Association (NRMCA) and the Insulating Concrete Forms Manufacturers Association (ICFMA) to conduct NFPA 285 testing of ICF wall assemblies and to develop and test window opening construction details that facilitate successful test results.
The first phase of this testing was completed this winter, and the draft reports are now being reviewed. Stay tuned – we look forward to sharing the exciting results once the final reports are published!
