The fire resistance rating is the based on the equivalent thickness of the concrete plus the equivalent thickness of the terrazzo. If the roof panels are covered with gypsum board, the thickness of the gypsum board need to be converted to an equivalent thickness.
What determines the fire rating of a building?
Fire Ratings 101
Fire ratings are determined by testing the materials' point of combustion. Codes from both the National Fire Protection Association and individual states provide information on the fire ratings of different materials.
What is the fire rating of construction?
Fire resistance rating (FRR) is the time in minutes or hours for which the construction materials or assemblies have withstood a standard fire exposure. How to measure the FRR of a material? Fire resistance ratings are calculated based on the time taken by a given material or structure to fail during a fire.
How does fire rating work?
For example, an FRL rating of 90/60/30 means that the construction element must maintain its structural adequacy for 90 minutes, integrity for 60 minutes, and insulation for 30 minutes during a fire incident. On some of our social media posts and case studies, you are likely to see FRL's written as 90/60/30.
What is the fire rating of a 2x4 wall?
Often used for exterior walls along property lines, this type of wall assembly allows for 2x4 wall construction to still meet the 1-hour fire-rating. In this wall assembly, type X gypsum is used on the interior followed by wood studs and mineral wool insulation, and finally a layer of 1-sided flame block material.
Which construction assembly is the most susceptible?
In the context of construction assemblies, a truss is generally the most susceptible to total failure resulting from the failure of a single component. A truss is a complex network of triangles used to provide support in a structure.