What does fire resistance mean? - FAQ

22 November 2019 Kingspan Insulation UK
Three key properties need to be considered when determining the fire safety performance of a building material: Reaction to Fire; Fire Resistance; and Fire Spread.

What is fire resistance?

Fire resistance is the property of a single material or assembly to withstand fire and continue to perform its given function and / or provide containment of a fire for a specified period of time. Thus, when this concept is applied to elements such as walls and floors etc., these building elements must resist the fire itself and keep the fire from spreading for a minimum periof of time as tested.

Each element has its own fire resistance properties, regardless of the reaction to fire classification.

Once a contained building fire has reached the point of flashover you need to rely on building elements with high fire resistance properties to protect the rest of the building from fire spread. Therefore, with regards to fire safety, the building elements must maintain their integrity and act as a partition to contain flames, smoke and heat to the original compartment.
How does this differ from reaction to fire testing?

The development of a compartment fire comprises four stages: Incipient; Growth; Fully Developed and; Decay, whilst flashover is a rapid transition, occurring at approximately 600 ºC, between the growth and fully developed stages. Reaction to fire is important during the early stages of a fire, but if a contained fire reaches flashover you need to rely on building materials with high fire resistance properties to contain the fire and prevent it from spreading.
How is fire resistance tested?

There are a number of National and European tests designed to determine the fire resistance of construction materials, however in relation to insulation materials, here are some of the most commonly used.

National testing:
•    BS 476-21: 1987 (Methods for determination of the fire resistance of loadbearing elements of construction)
•    BS 476-22: 1987 (Methods for determination of the fire resistance of non-loadbearing elements of construction)

European testing:
•    BS EN 1365-1: 2012 (Fire resistance tests for loadbearing elements – walls)
•    BS EN 1365-2: 2014 (Fire resistance tests for loadbearing elements – floors and roofs)
•    BS EN 1364-1: 2015 (Fire resistance tests for non load-bearing elements – walls)
•    BS EN 1364-2: 2018 (Fire resistance tests for non load-bearing elements – ceilings)

You can download the full testing standards from the British Standards Institution shop.

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