Modified Fire Resistive Construction



One of the primary goals of underwriting for any property insurance policy is determining the risk of fire. And one of the main considerations in making that determination is assigning the proper construction class. What are the materials? What percentage of the structure consists of each kind of material? How much damage will the building sustain when exposed to fire? Properly identifying the construction class can help the underwriter rate the risk more accurately.

ISO defines six construction classes for commercial buildings: 

  1. Frame
  2. Joisted Masonry
  3. Noncombustible
  4. Masonry Noncombustible
  5. Modified Fire Resistive
  6. Fire Resistive


This Construction Brief will give you an overview of ISO‘s Construction Class 5 — modified fire resistive construction. When you‘ve completed this course, you‘ll know what an ISO report means when it says a building is modified fire resistive construction. And you‘ll understand why a particular structure is — or isn‘t —modified fire resistive.

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