When do we talk about fire resistance or reaction to fire during a fire?

From the moment of ignition, which can hatch over a longer or shorter period of time, to the propagation of flames, we speak of reaction to fire. In this phase, the behavior of the materials is very important. They must ‘burn slowly’, do not drip, produce little smoke, in order to prevent the fire from developing and spreading and to allow the escape as orderly a as possible. If we think about the reaction to fire of wood, for example, according to EN13501 it is D S2 d0. This acronym means that when exposed to fire it burns (D goes from A to F, in ascending order of class), smokes (S goes from 1 to 3, again in ascending order), and does not drip (d goes from 0 to 2).

 Exodus takes place at this stage, where it is crucial to choose the right strategies, such as materials with a good reaction to fire, smoke-tight doors to facilitate escape, orderly escape routes and fire-fighting equipments.

Afterwards (we are talking about five minutes from the spread of the flames, not two hours…) we arrive at the so-called ‘flashover’. This is generally defined as the transition to a fully developed fire in which all combustible materials in the compartment are involved in the fire mainly due to the radiation caused by the products of combustion. From then on, laboratory tests simulate fire resistance, generally the ability to prevent the fire from spreading from one compartment to another.

R, E, I

Fire doors are the main elements of compartmentalisation, all the more  since they have to fulfil multiple functions. They are fire resistant.

In most sites created by copy-paste, we find the fabulous definition R.E.I., Resistance Hermeticity Insulation. Something epic, like liberté, fraternité, egalité. Jokes aside, this definition was, in Italy, the one prior to the introduction, in 2004, of EN1634-1, the European standard by which doors are tested.

In the European system, R is the load-bearing capacity, e.g. in a wall, the ability to support a load despite fire for the specified time (e.g., R120, or REI120, would be the capacity of a fire barrier for 120 minutes). It does not apply to doors.

In Italy today, it is not wrong to define a door EI 120, REI 120, as Article 1, paragraph 4 of Ministerial Decree 21.06.2004 states that an EI2 120 door is equivalent to a REI 120 door according to the old national standard. It is just obsolete!


Fire doors are tested according to EN1634-1. Theoretically, internal doors could still be tested with UNI 9723.

For both tests, a ‘normalised fire‘ is simulated, with the oven heating curve of ISO 834.

Within the test we evaluate (click here to go to a video where I talk about this from 8:50)

Integrity – E

  • cracks or openings of a certain size: E fails if you create through holes, apart from the threshold, with a diameter equal to or greater than 25 mm (25 mm gauge) or if you can insert a 6 mm gauge into a through hole and slide it linearly for 150 mm in two directions without damaging the seals;
  • ignition of a cotton pad;
  • persistent flame (more than 10 seconds) in the unexposed part.

Thermal Insulation -1

On two levels, with the suffixes 1 and 2 (2 for the additional procedure). The thermal insulation has central thermocouples to the panel that must respect an average temperature difference of 140 degrees centigrade, the other thermocouples must not exceed 180 degrees centigrade. The frames have a temperature difference limit of 180 degrees for wooden frames and 360 for metal frames. On the panel, thermocouples are placed 100 millimetres from the edge are I2. In the European standard, an ‘additional procedure’ is determined, whereby,under the request of the ‘sponsor’, thermocouples may be applied at 25 mm from the edge of the door to determine the I1 tightness. Clearly, being closer to the edge, it is more difficult to comply with this parameter. The I1 tightness is required, for example, in the Netherlands.


Once the test has been carried out, the door is classified according to EN13501-2. Below is an example of classification

EI1 90, EI2 120, E180

It means that the door has maintained integrity up to 180 minutes, I2 up to 120, I1 up to 90 minutes.


Dimensional extensions depend on the test result. If I test a door for 30 minutes and do 31 minutes, the maximum measurement I can produce will be the one tested.

If, on the other hand, I do 36 minutes, I obtain in the direct application range of the results – for hinged doors – a 15% extension of linear measurements with a 20% limit in area.

This means, that if I test a 1000×2000 door, doing simple calculations, with 31 minutes I make at most that measurement, with 36 I make at most 1150×2300. In reality, I can never make that measurement because I am within the 20% area limit. In fact, the sample area would be 2 square metres, so the maximum area would be 2.4 square metres. So I will only be able to do, for example, 1150×2050 or 1040×2300, which are under the 20% increase in area.

For slide doors, the allowed increase is 50% of the linear measurements.

The famous 6 minutes mentioned earlier are defined in the standard as “extra time” or “overrun”, as follows:

30 minutes -> 36

60 minutes -> 68

120 -> 132


In general, paints can be applied, thickness increases with some limits. Some of the variants are included in the field of direct application (wooden doors, thickness increase due to material identity, application on the faces of laminates and ornamental veneers up to 1.5 mm thick).

Also with regard to construction components, such as locks, hinges, handles and door closers, there are components that must be tested, others may have to be replaced. In general, all changes that are not included in the direct scope of the results should be searched for in the extended scope of the results, completing an EXAP, more information on which can be found in the dedicated section of the website(

Also with regard to construction components, such as locks, hinges, handles and door closers, there are components that must be tested, others may have to be replaced. In general, all changes that are not included in the direct scope of the results should be searched for in the extended scope of the results, completing an EXAP, more information on which can be found in the dedicated section of the website (https://chemollifire.com/en/testing/exap-extended-evaluation/)


If a glass with a small size is tested, the door can also be made without it. If the measurement is large, the door is called glazed and can only be produced with glass.


Soundproofing is also very often required. To find out what tests the doors are subjected to, visit the NOISE INSULATION section of our website (METTERE LINK FONO ISOLAMENTO IN INGLESE)


Smoke tightness is becoming increasingly popular, which is tested according to EN1634-3. To find out what tests the doors are subjected to, visit the SMOKE TIGHTNESS section of our website (https://chemollifire.com/it/test/tenuta-ai-fumi/)



When testing doors, both sides are normally tested, opening towards the oven and opening on the opposite side of the oven. There are cases – very special indeed – where according to certain paragraphs of the standard only, one side can be tested. We are talking about doors with a wooden leaf and frame, symmetrical in their composition, where all the hardware elements have already been tested and the evidence is available. By default, the door could be described as ‘one-sided’ and therefore only suitable for fire on one side (an obvious limitation).

 Most of the available ovens are 3×3 metres, and generally during testing one test can include either two single-leaf doors in double exposure, or a double-leaf door on one of the two sides to be tested.


In the European test, the change from double-leaf door to single-leaf door is only possible – under certain conditions – by means of an EXAP (https://chemollifire.com/en/testing/exap-extended-evaluation/), whereas with the homologation regime this is permitted in accordance with DM 21.06.2004, Annex C, paragraphs 1a, 1b.


The supports (walls) on which the element is tested are also important. The standard contains so-called standardised supports, i.e. defined in the standard (specifically, in EN 1363-1:2012). The standardised supports are divided into two categories: rigid and flexible. By rigid, we mean masonry, by flexible, the plasterboard wall.

If I make a test on a non-standardised substrate, such as an X-lam wall, this will be understood as “associated support structure” and therefore that door can only be mounted in reality on that substrate.

If I make a test on a rigid or flexible standardised support, wooden leaf doors with a wooden frame, I can switch from a rigid to a flexible support in reality.

If I make a test on a flexible standardised substrate wooden leaf doors and a metal frame, I can switch in reality from a rigid substrate, but not vice versa.

Metal doors need to be tested on both rigid and normalised support (that’s two tests). This is why when we buy a metal door, it has a different ‘certificate’ if it is for masonry or plasterboard.


Generally speaking, an accommodation facility is built around a staircase leading to the floors, the head room if there is one is a single-leaf EI60, the doors leading to the staircase are double-leaf, with an EI60 handle, the room doors are EI30, the closet door EI60. As far as the wire is concerned, the room doors open inwards, the closet door outwards.


Customisation, large sizes, flush doors, doors that combine fire resistance with soundproofing.


As described above, there is no right and wrong. To get it right, you would have to make10 tests, then you have to get into the merits of the individual company and understand what its identity values, production lines and markets are. Once you have analysed the existing products, you can get an idea and think that testing everything is perhaps too much, but in the meantime start with the typologies that allow you to enter the market and create a position for yourself and to develop in a second moment.


When it comes to testing, we provide our experience and our KNOW-HOW.

As specialists, we offer comprehensive advice during all stages of laboratory testing, from design to documentation of results.


Listening is the most important phase of our interaction: we want you to develop a product that is the sum of your identity and needs.

First, we try to understand your real needs, the channels and markets you want to measure yourself against.

Then we show you how the testing and certification process takes place: we need to engage with you, to fully grasp your point of view. Then we develop a proposal that respects – compatibly with the required performance – your product lines, your production lines and, as far as possible, potential economies of scale using products and methodologies already established in your company.


Beyond the opportunities, which we will illustrate to you, we will then advise you on what we would do in your position.

We will advise you with our experience on what, how and where to test. In which laboratory to test? In the one best suited to your needs.


Once the key has been turned, we prepare a project that is comprehensive in all details. Which materials and components to use, an important part of our dialogue on which we can best advise you. In addition to this, a cost sheet and a weight forecast, to allow you to check whether your goals will be achieved. Using industry best practices, we are convinced of this.


A consultants we give advices, then we leave it to the client to put it into practice. We are not like that: we take off the tie and put on our work clothes when needed. We launch the production of the samples, we are present during the gluing of the doors, we offer support during the process and shoeing, we proceed with our technicians to the installation of the samples in the laboratory and we are physically present at the testing. We manage the post-test documentation review phase, explain the documentation to you and remain available for all issues related to results management.


In addition, we offer you comprehensive consultancy during all stages of certification, assisting you:

  • in the planning and budgeting of activities, to determine an investment plan;
  • During all the communication with the notified body;
  • during sampling (withdrawing products for testing);
  • in implementing your FPC – Factory Production Control;
  • In preparing the necessary documentation including instructions and labels;
  • with our presence during initial inspections;
  • afterwards, as support for all management issues.