Fire Test standard EN1366-3

Essential for life safety and asset protection: correctly installed firestop products in fire compartments

Life safety and asset protection are key requirements of building regulations across the globe.

To comply with these codes, it is essential to design and plan fire compartments at an early stage of a construction project. For compliant compartmentation, there is one hidden and high-risk potential hazard that must be addressed – the sealing of penetrations through fire rated walls and floors. For this reason, designers, architects and building owners need to know that a manufacturer of firestop systems takes the testing of through-penetration systems seriously.

But what does a fire test look like, what are the most trustworthy standards, and what are the key parameters and challenges? This article provides some of the answers.

Fire Testing - An insight into testing of Firestop Systems

Fire compartments are often complex applications

There are two main dimensions to fire testing.

The first is focused on testing and evaluating the ignition or combustibility characteristics of a certain building material. These fire test standards relate to the flammability of the firestop material or product itself. The product or material is assigned to one of a number of different classes which describe both its behaviour in a fire and its contribution to a fire. This test is also known as ‘reaction to fire’.

In Europe there are very specific flammability classes according to the primary recognized standard EN 13501-1. These range from A1 (non-combustible) to F (combustible / easy flammable). A further classification ‘s’ rates the smoke emission level from 1 (absent / weak) to 3 (high), while the classification ‘d’ rates the production of particles and flaming droplets from 0 (absent) to 2 (high).

A building material undergoing fire testing (source Hilti)

Fire resistance – the real thing in firestopping

The second dimension of fire testing evaluates a complete firestop solution as a complete through-penetration system. This considers the effectiveness of a fire-rated wall or floor, base material, type of
penetrant, opening sizes and much more. These tests determine whether a complete system is able to reinstate the fire rating of a wall or floor for a period of time. In other words, these are tests of a product’s effectiveness as an application, not of its combustibility.

Improve life safety and asset protection with tested firestop systems

Firestopping is the process of installing tested and compliant third-party materials into openings in fire-rated barriers with the aim of restoring hourly fire-resistance ratings.

A wall or floor may have been constructed with a fire-resistance rating, but when an opening is created for conduit, cable or other service elements like heating or wastewater pipes, the original fire-resistance rating is compromised. A properly firestopped opening restores the barrier’s ability to resist the passage of fire and smoke.

The performance characteristics of building elements like walls, floors and penetration installations are called fire resistance. This clearly determines the very important field of application. The field of application defines exactly how a firestop product can be installed.

Therefore, a product such as a firestop sleeve has no rating per se. It is the fully tested field of application in a listing or in an approval / assessment that is important. This gives designers and installers information on how to specify and install a certain firestop product. Crucially, this also allows them to put the right product with the right field of application into a specification. Generic specification clauses, which may just refer to a fire rating or be even more generic, set the stage for improper installation. When this happens, major concerns emerge when it comes to the approval and inspection of a building.

Test standards – compliant, reliable and transparent

Test standards define testing procedures and frame conditions. For Europe, the predominant test standard is EN1366-3, a state-of-the-art standard applicable in all member states of the European Union. Many countries globally have incorporated EN1366-3 into their national codes. This is because the European standard takes fire testing to a high level of security, reliability and transparency, providing designers, building authorities and building owners with both trust and confidence.

However, an approval or assessment (European Technical Assessment = ETA) made as a result of an official test based on EN 1366-3 can be complex. This is because it not only contains all parameters of a tested field of application, but must also provide clarity and transparency. However, high-level and knowledge-based test evidence gives you the confidence that every product will perform as expected – and that the fields of application for different products can be compared correctly.

For this reason, the overriding principle of established test standards like the EN 1366-3 is “what you test is what you get”.

How fire-resistance tests work

Fire-resistance tests are designed to replicate a product’s intended end-use. Firestop products are built into an appropriate supporting construction. The specimen is then built into a restraint frame, which is mounted on the front or top of a furnace. The effect of the penetrations on the specimen’s integrity and insulation performance is the target of this test.

Fire test assembly created to meet strict test standard conditions (picture: Hilti)

The temperature within the furnace is controlled according to an internationally accepted time/temperature regime. The time/temperature and pressure regime within the standard is intended to represent a post-flashover condition. Flashover is the point at which all objects in a fire compartment have ignited. Testing is continued for the required duration (e.g. 30, 60, 90,120 minutes) or until the specimen fails and it is no longer safe to continue. Failures relate to integrity, insulation and load-bearing capacity (if appropriate).

Cold fire side after 2 hours: danger of self-ignition and insulation failure (picture: Hilti)

The challenges faced by firestop manufacturers are manifold, but the key priority of many is to test products for the most common jobsite applications. Manufacturers like Hilti take a broader approach. With international experience via its direct engineering and sales force, its own development and research capabilities and its own production, Hilti is able to provide a much wider variety of approvals. In addition, it uses testing requirements as a direct springboard into innovative product and technology development.

Manufacturers define an assembly they want to test. For example, it could be a cable tray with a number of low voltage communication cables. A common application might be for a 2-hour fire rated concrete wall in a building compartment, such as in a hospital. In such a case, the wall depth might be defined as being 200mm.

The next decisions to be taken concern the opening, which will have multiple variations: opening size, opening characteristic (round opening, square opening or irregular opening). Then the penetrants have to be defined: the kind of cable tray along with the types and number of cables. The stability of the specimen in real-world situations is also influenced by mechanical conditions in a fire. Cable tray supports, cable bundles or pipes have to be fixed to withstand movement and mechanical fluctuation in a blaze. This is also defined for the test. Last but not least, the distance criteria within the penetration (distances to seal edges, between penetrants or between different penetrant types, metal pipes, plastic pipes, trays and cables) is crucial to avoid interrelations of the different penetrants.

Intumescent Hilti Firestop Blocks before and after a test. Many influencing factors need to be considered for successful testing (pictures: Hilti)

In the European test standard EN 1366-3 for penetration seals it is explicitly mentioned that the test specimen shall be either a) fully representative of the service and penetration seal used in practice, including any special features which are unique to that installation or b) a standard configuration which is deemed to cover a wide range of practical applications.

In order to avoid boundary effects, the distance between the perimeter of the penetration seal and the internal surfaces of the furnace shall be not less than 200mm at any point. Other guidance for manufacturers within the standard includes:

• Supporting construction
• Large cable penetration seals
• Small penetration seals
• Pipe penetration seals
• Mixed penetration seals
• Critical pipe/cable approach
• Pipe end configurations

These test specimen(s) shall be installed, as far as possible, in a manner representative of their use in practice.

A test then is subsequently evaluated by test specialists from the official accredited test laboratory. The results are then transformed into a test report, giving the manufacturer all details of a test run.

Most commonly the following criteria are evaluated:

• Fire containment
• Flaming and glowing on the non-fire side
• Number, size and character of gaps and cracks in the specimen
• Heating on non-fire side and temperature increase on defined areas of the surface of the specimen (this defines the so-called insulation rating).

The assembly is then given a rating, expressed in hours or minutes, based on the following conditions of acceptance:

• E = Integrity – the structure’s ability to NOT allow the passage of fire or production of gas or vapor to the area NOT exposed to the fire.
• I = Thermal Insulation – the ability of a structure to reduce (within a temperature limit) the transfer of heat to the unexposed (cold) side.

Integrity and insulation criteria measuring the resistance against flames (integrity) and heat (insulation)

Manufacturers can then follow a distinct process to achieve a CE marking, including third party production control. They are then able to provide a declaration of performance to customers, having clearly published the tested “field of application”.

The CE marking is a part of the EU’s harmonization legislation and supports fair competition by holding all companies accountable to the same rules. This ensures that consumers enjoy a consistent level of health, safety, and environmental protection.

Hilti offers firestop products with an ETA and CE marking. They are comprehensively tested according to test standard EN1366-3 and come with a broad field of application-enabling specifiers, allowing designers and architects to easily specify and select firestop products for all key applications in fire-rated walls and floors.

If you would like to find out more then why not ask, leave a comment below or checkout our other Firestop articles here.