Fire resistance test of timber doors

Fire resistance is the ability of a closure to meet the requirements of integrity (E), integrity and isolation (EI1 or EI2) or integrity and radiation (EW) for a specific period of time.

The fire resistance requirement is an essential requirement for the following types of closures:

• Pedestrian doors
• Industrial, commercial and garage doors
• Roll-up closures

and must be verified by carrying out one or more tests according to EN 1634-1, to obtain the classification E, EI1 or EI2, or EW, followed by the level expressed in terms of maintenance time of the requirement (s), from 15 to 240 minutes.

Definition of fire door: pedestrian or industrial door including any frame or guide, leaf, rolling or folding elements, etc. made to achieve fire resistance when used to close permanent gates in fire-resistant separation elements. This includes how the assembly is composed, such as all the side panels, windows, fanlight panels, together with the door accessories and any gasket.

Classification

According to standard EN 13501-2, the classifications of fire resistance of timber doors shall be developed based on the tests carried out in accordance with standard EN 1634-1.

Fire integrity, denoted with the symbol E, is the ability of the structure element that acts as a partition to withstand fire applied at one side, without transferring the fire to the unexposed side as a result of flame or hot gas penetration to the other side. Fire integrity assessment is carried out according to three aspects:

− fractures or holes exceeding given dimensions, verified by penetration of a gap gauge of diameters of 6 mm and 25 mm,

− a cotton pad is ignited or glows – touching the surface of the unexposed side of the tested sample for 30 seconds,

− the existence of flame on the unexposed surface – lasting more than 10 s.

Fire insulation, denoted for the doors with symbols I1 or I2, is the ability of the structure element to withstand fire applied at only one side, without transferring the fire to the unexposed side as a result of significant heat transfer from the heated side to the unheated side.

Fire insulation assessment is carried out according to the following:

− in the case of fire insulation class I1:

• measurement of the mean temperature rise of the unexposed surface of the door leaf, which should be limited to 140°C above the initial mean temperature;


• measurement of the maximum temperature rise, which should be limited to 180°C at any point of the unexposed door leaf surface, without consideration of the measurement of temperature on the door leaf within the area located at less than 25 mm distance from the borderline of the visible door leaf edge;


• measurement of the temperature rise at any point of the door frame, measured at the distance of 100 mm from the visible edge of the unexposed door leaf surface, provided the door frame is wider than 100 mm, or otherwise, at the door frame/supporting structure border, which should be limited to 180°C.

− in the case of fire insulation class I2:

• measurement of the mean temperature rise of the unexposed surface of the door leaf, which should be limited to 140°C above the initial mean temperature;

• measurement of the maximum temperature rise, which should be limited to 180°C at any point of the unexposed door leaf surface, without consideration of the measurement of temperature on the door leaf within the area located at less than 100 mm distance from the borderline of the visible door leaf edge;

• measurement of the temperature rise at any point of the door frame, measured at the distance of 100 mm from the visible edge of the unexposed door leaf surface, provided the door frame is wider than 100 mm, or otherwise, at the door frame/supporting structure border, which should be limited to 360°C.

Radiation, denoted with the symbol W, is the ability of the structure element to withstand the action of fire applied at only one side, to limit the possibility of transferring fire as a result of significant heat radiation by the element or by its unexposed surface to the nearby materials.

The samples for which the radiation criterion has been assessed shall be identified by adding the symbol [W] to the classification (e.g. EW).

Test equipment

The test equipment specified in EN 1363-1 must be used in detail:

– A system capable of generating, within a closed combustion chamber, a progressive heating, so as to be able to expose the test sample to a simulated fire

– A control system for test parameters (temperature and pressure in the fire chamber

– A containment frame for the test sample (support element and door)

– Dedicated equipment for detecting the temperature of the fire chamber and the non-exposed side of the sample

– Equipment for measuring sample deformation

– Equipment for verifying the integrity of the sample

Thermocouple application scheme

The application of thermocouples to measure the temperature of the unexposed side of the sample has a dual purpose:

– give an indication of the average temperature trend of the sample, even considering separately, when relevant, discrete areas (glass)

– monitor some critical points, possible cause of the loss of insulation (leaf-frame perimeter)

The documents in relation to the tests carried out

The documentation issued by the laboratory is the Test Report and Classification Report, a document for commercial use.

The main informations in the Test Report are:

– Applicant of the test
– Sample on test
– Trade name
– Date of execution of the test
– Reference standard

The mandatory informations are:

– Description of the sample
– Construction and/or assembly methods of the sample
– Sample conditioning
– Methods of carrying out the test
– Evaluation criteria of the test
– Observable
– Result of the test
– Direct application field

REFERENCE
European Standards

– EN 13501-2:2016 – Fire classification of construction products and building elements – Part 2: Classification using data from fire resistance tests, excluding ventilation services.

– EN 1634-1:2014 – Fire resistance and smoke control tests for door and shutter assemblies, openable windows and elements of building hardware – Part 1: Fire resistance test for door and shutter assemblies and openable windows.

Author: Pamela Mattioli

Pamela Mattioli is an International Fire Doors Consultant dealing with Research, Innovation and Training. She has been dealing with fire doors certification all over the world, helping companies in the design of fire doors for obtaining any International Certification, which allows them to be more competitive and position themselves in the highest segment of the market. Additionally Pamela Mattioli is collaborating with relevant laboratories and certification bodies in sampling inspections and FPC. She is also an entrepreneur who owns two companies in Italy.

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