What is the temperature requirement that a 1-hour fire-resistive assembly must withstand during testing?

A 1-hour fire-resistive assembly is required to withstand a temperature of 1700°F during testing to be classified as fire-resistive. This temperature is established to ensure that building materials can provide necessary protection against the spread of fire and maintain the structural integrity of the assembly for at least one hour. This is crucial for allowing occupants time to evacuate the building safely in the event of a fire.

The testing conditions are standardized to ensure uniformity in assessing the performance of materials in real-world fire scenarios. Withstanding this specific temperature helps demonstrate not only the ability of the material to resist flames but also to insulate against heat transfer, providing a barrier during a fire incident. The other temperature options do not meet the established standard for a 1-hour fire-resistive rating.