Fire resistance or fire rating is the measurement of how much time a certain material or assembly can withstand either a standard fire or astandardized fire resistance test. It is an important consideration when building a structure, as certain materials may spark a blaze, while other materials, when they come into contact with fire, do not compromise the structural integrity of the building and thus provide more protection against flames, smoke and heat.
Fire resistance is typically measured concerning a specific fire test, such as the ASTM E-119 test for walls, floors, and roofs. The time required for heat to penetrate material is measured and compared against established standards. Generally, the measurement of fire resistance is one of time until failure, (the time it takes forheat to penetrate the material risking a structures integrity). The time may be measured in either minutes or hours.
Fire ratings can also be assigned to an assembly of building materials by an independent laboratory. The laboratory tests the materials for the fire rating and may or may not use the ASTM 119 test. This is why the fire ratings listed on building materials or products may differ when comparing different manufacturers or products.
In some areas, such as California, a minimum fire rating is required to pass certain building codes. In California, a wall must be rated as 1 hour fire rated in order to pass certain code requirements. This means that the wall assembly must withstand a fire test, where it is exposed to fire for one hour, with the temperature being increased at certain intervals. Once the temperature gets to a certain point, the material will began to be damaged and eventually fail the test. Fire resistance ratings have also been adopted in many other countries for similar reasons.
Fire resistance is important for any structure, as even the smallest blaze can cause massive amounts of smoke and damage to a building. Fire ratings on products and materials help determine which materials provide the most protection from fire. This helps homeowners and construction companies to make the best decisions when selecting materials for their buildings. Additionally, building codes and regulations that require certain minimum fire ratings are meant to protect the public from dangerous building materials. Fire resistance is thus an important factor in keeping structures safe and to protect public life from danger.
