Who can forget the horrific images of the charred Grenfell Tower?

Fire safety experts said that the building’s external cladding fuelled the rapid spread of the Fire. The cladding could be seen burning and melting, adding credence to the belief that it was not made of fire-resistant material. This can be the unfortunate state of any high-rise building that cuts corners when it comes to fire-safety material.

It is important to note Key observation 1.1 of the Grenfell Tower Fire Preliminary Report which states: The external cladding system installed on Grenfell Tower was not compliant with Regulation B4 (1), contributing to the observed failure of the fire safety measures provided within the premises.

According to the Evening Standard, the ACM PE cladding panels used in Grenfell Tower were given a Class 0 rating by the British Board of Agrément (BBA) in 2008. The rating was used to determine “limited combustibility” in building products. However, the Grenfell Tower inferno clearly showed that these Class 0 external cladding panels were combustible and found to be a key factor in the fire’s rapid spread, by acting as a source of fuel.

Without a doubt, fire safety is of utmost importance in high-rise constructions. However there is considerable confusion on the safety recommendations for cladding material used for facades, as these products differ in base material, features, composition, etc. Consequently there are diverse testing methods that test different parameters for determining the “fire safety level” of various materials

So lets’ understand a little more about these crucial Fire Safety Classifications for building material which can make the vital difference between safety and disaster.

The UK Building Regulations on Fire Safety (1991) were replaced by the more robust Euroclass System for Fire Safety Classification in the year 2000, having been introduced by the European Union (EU) to remove trade barriers between individual member states. However, the problematic “Class 0” classification of the archaic UK system which was to be shortly phased out, continued to be used, resulting in disasters like Grenfell Tower.

So what exactly does FR Class 0 indicate?

The 1991 UK Building Regulations on Fire Safety introduced a classification for materials used in wall and ceiling linings, to determine the surface spread of flames with Class 4 being the worst and Class 1 being the best (the least distanced and slowest spreading of flames). Class 0 was introduced to indicate when Class 1 materials have fire propagation index and sub-indices are 0. This measures spread of flames and also takes into account the (limited) amount of heat released from the surface of a product. What is noteworthy is that this method does not test the combustibility of a composite material.

After, the formation of the European Union, the Euroclass System for Fire Safety Classification was made mandatory in EU countries, and in 2007 another testing standard EN13501, was introduced to classify building materials’ fire behaviour and contribution of material in a fire. These products are rated A1 – F, depending upon the contribution to the fire load, with Classes A1 and A2 being the best (as non-combustible), Class B being Limited Combustible, and further classifications of C- F  being totally combustible.

The differences in parameters measured in these diverse classifications, have caused the contentious Class 0 issue. So let’s drill down and get to the bottom of the Class 0 scam.

Class 0 V/s Class B – A world of Difference

There is a misleading tendency to equate Class 0 of the old UK system with the Euroclass B rating. However, Class 0 is not, and will never be, comparable with Class B of the Euroclass system, for the simple reason that two different parameters are measured by each of these systems. National Class 0 measures the spread of flame and the amount of heat release only from the surface of a product; whereas the Euroclass system certifies building material based on two types of tests: Single Burning Item Test & Single Flame Source Test.

Single Burning Item (SBI) test measures the  Fire growth rate (FIGRA) at different flaming conditions in total heat release (THR); Smoke growth rate (SMOGRA) in total volume of smoke produced (TSP); Flame spread in different directions; Flaming droplets and their burning behaviour. The Single Flame Source Test or reaction to fire test is the major test to assess the core material’s behaviour upon burning or ignitability, or contribution to fire of the building product by direct flame, to measure the self-extinguishing behaviour of core material on flame and off flame.

It is important to note that a product, classified as the more comprehensive class B-s1 d0, invariably satisfies the characteristics of a Class 0 product, but never the other way around, i.e. a product classified as Class 0 may not meet the Class B criteria, because the subject of testing, as well as the size of testing differ in the two systems – the Euroclass System being far superior, as explained above.

This crucial fact is something every construction stakeholder needs to be aware of, since ignorance cannot be condoned when lives are at stake. Class 0 is no substitute for Class B and A2 material and hence do not to be scammed by corrupt suppliers who promote Class 0 material as fire-safe. Remember, budgetary constraints can never justify disasters like Grenfell that saw horrendous destruction of innocent lives and hard-earned property.

As a responsible corporate, Eurobond strongly appeals to decision makers of the construction industry, to stop allowing Class 0 certified composite materials to be used in applications requiring fire safety, because one Grenfell Tower disaster, is one too many!