What are FRLs?
In Australia, fire ratings levels (FRLs) are required by the National Construction Code as expressed in the "Building Code of Australia - volumes 1 and 2" (BCA).
FRL requirements are expressed by the BCA in the number of minutes of protection of three criteria:
- Structural adequacy
The rating is expressed in this order, so an FRL of 60/120/90 signifies that the coating provides:
- 60 minutes of structural adequacy
- 120 minutes of integrity
- 90 minutes of insulation
This rating is achieved by subjecting a specimen to the standard time temperature curve regime as set out in AS 1530.4-2014 to AS4100 regression analysis post May 2022.
The minutes stated for each criteria are an indication of the time the product continues to perform when subject to the standard fire test, as outlind in the Australian standard AS 1530.4-2005.
The times shouldn't be confused with how well a given product will perform in an actual building fire where the size and intensity of a fire is subject to a number of variables. The FRL simply provides a consistent way of comparing the performance of a range of products.
As the structural steel components of a building do not provide a barrier to fire and smoke spreading throughout a building only the structural adequacy criteria is relevant to the FRL when applied to the structural steel components of a building. As such FRL requirements for structural steel are expressed, within the BCA, as being between 30/-/- and 240/-/-.
bca frl requirements
The fire protection requirements for buildings, as specified by the BCA, are determined by three criteria:
- The building classification
- Fire compartment size
- Rise in storeys (building types)
what are building types?
Buildings are classified as types A, B or C depending on the number of storeys and their risk level:
- Type A - 3 or more storeys - these high rise, high occupancy buildings are subject to the highest risk and therefore are the most fire resistant
- Type B - 2-3 storeys - are an intermediate level between type A and type C
- Type C - 1-2 storeys - these buildings are the lowest risk and therefore have the least level of fire resistance
It should be noted that the building type, apart from being determined by the number of storeys, is also determined by the building class. Further information on building types and classes can be found here.
The FRL requirement varies depending on the building type.
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