Introduction
From the point of view of reaction to fire, the construction products must be tested according to the classification standard EN 13501-1 (Euroclasses). This is how it is showed in the regulations related to safety in case of fire in Spain (Technical building code and fire safety regulation in industrial facilities) and in the rules for obtaining the CE mark.
Euroclasses reflect the behaviour of a product in case of fire and its potential contribution to its start and development always taking into account the reference scenario considered in the EN 13501-1. (A fire initiated in a room, which can grow and eventually reach flashover).
Influence of the end use application
The classification standard EN 13501-1, explains that the fire behaviour of materials or products depends directly on the end use application and therefore must be tested of this way (Except that a CE mark standard applicable to the product or material specifies another mounting and fixing method). That is, for the same product or material, its reaction to fire classification can be totally different depending on its end use application. Following are shown two examples:
Example 1: Polystyrene
The polystyrene (expanded or extruded) can reach a classification of reaction to fire E. But if this same product is tested in a standardised assemblies simulating, according to EN 15715, simulating the end use application in a construction element covered with gypsum plasterboard could achieve a fire reaction classification B-s1,d0
It could also reach a euroclase B-s1, d0 if the polystyrene is covered by plaster or mortar
In these conditions, the polystyrene is covered by another material that determines to a greater extent the fire behaviour of this system and therefore its contribution in the start and propagation phase of the fire will be very limited.
Example 2: Paint
A paint should always be tested on a substrate. Currently, there is a series of standardized substrates that can be used in tests to simulate different end use applications. But, the paint will behave differently depending on the substrate. A paint applied on a standard sheet steel substrate can achieve a euroclass B-s1, d0. But, if this same product is applied in the same conditions as the previous case but on a standard wood substrate, the euroclass that could be reached would be D-s3, d0 or C-s3, d0.
As it has been demonstrated with the previous examples, the reaction to fire of a product will depend on the end use application where it will be installed, not the product itself.
Types of Euroclasses
There are different types of euroclasses depending on the place where the products will be installed, that is, end use application:
- For construction products excluding floorings and linear pipe thermal insulation products, normally walls and ceilings. It does not present any type of subscript, B-s1, d0
- Linear pipe thermal insulation products are indicated by the subscript L. BL-s1, d0.
- Floorings are indicated with the subscript Fl. Bfl-s1
- Roofs exposed the external fire are indicated with the Subscript Roof (tX), (where X is the type of test, type 1 is required in Spain). BRoof (t1).
It is important to highlight that it is not possible to make any kind of equivalence between the different Euroclasses since each of them refers to a different fire scenario and, therefore, different end use applications.
Conclusions
The test results related to the behaviour of the test specimens of a product under the particular conditions of the test, they are not intended to be the sole criterion for assessing the potential fire hazard of the product in use
To achieve adequate levels of safety, it is necessary to take into account other aspects related to the fire safety of buildings, which are explained in the Spanish regulation CTE and the RSCIEI, in the chapters of prevention and fire protection.
The construction products must be tested and taken into account in relation to end use application. To evaluate a product in this way allows a better knowledge of its possible response in case of fire
Finally, a product may obtain as many classifications under the Euroclasses as end use applications may apply.
Bibliograph:
EN 13823. “Reaction to fire tests for building products – Building products excluding floorings exposed to the thermal attack by a single burning item”.
EN 15715. “Thermal insulation products – Instructions for mounting and fixing for reaction to fire testing – Factory made products”.
EN 13501-1. “Fire classification of construction products and building elements – Part 1: Classification using data from reaction to fire tests”.
EN 13501-5. “Fire classification of construction products and building elements – Part 5: Classification using data from external fire exposure to roofs tests”
Fire Safety Consultant