What does A2 mean? What’s the difference between an ‘A’ and a ‘B’ board

Download our fire safety brochure

The Euroclass system, which is the leading standard in Europe for fire safety classification of building materials, consists of the levels A1, A2, B, C, D, E and F. Both A1 and A2 mean that the classified material is non-combustible. Levels B-F are for combustible materials, although there is quite a wide variety between them. It’s mandatory to use this standardized system with consistent quality levels. However, there are still often referrals to old standards. This leads to confusion and incorrectness, as they can be based on completely different test methods.

Fire performance testing

The Euroclass system is based on a stacked level of testing: with every class, there are more strict rules to comply with. In class F, either nothing is tested or a product failed to achieve a higher level. Class E only tests with a small flame for a short time. For classes D to B, the method of SBI-testing is used.

A1 and A2 classifications can be given on the basis of a successful non-combustibility test. The calorific value is defined here, which should be of a very low value.

Fire behaviour of different Euroclass B boards

We always recommend using non-combustible materials for facade cladding (and insulation) on high-rise and high-risk buildings. These are Euroclass A1 and A2 materials.

Euroclass-B cladding is very well-suited for many applications (for instance houses or low-risk buildings), especially when used in combination with non-combustible stone wool insulation. However, it is important to take in mind that B panels differ from one another. First of all, the material of which they are made (combustible or non-combustible by nature) and the calorific value are important. There’s a wide variation in calorific value within Euroclass B boards. In addition, the amount of binder used is an important factor.

Why are calorific values of facade cladding so important?

Compared to other Euroclass B panels, the calorific value of Rockpanel is very low, meaning that it does not have a lot of organic material in it that can contribute to a fire. Even more so, in case of fire this binder will decompose, but not burn, because of the core of basalt fibres that do not burn.

Although HPL panels have a very high caloric value, they also have a Euroclass B classification. This is because the added fire retardants slows down the ignition during the limited time and limited fire load of an SBI test. In real life, the fire retardants are consumed at some point and the panel would then still contribute heavily to the fire due to its high calorific content. Rockpanel on the contrary, would still not burn, because of its basalt core and very low calorific content.


Everything you need to know about fire safe facade cladding

Are you an architect or contractor and would you like to get an in-depth presentation about fire safety in relation to facade cladding? We’d be happy to come to your office for a free, informative Lunch & learn CPD session about this topic.

Register now!
Corporate, meeting, business, team

Interested in a free Rockpanel A2 (FS-Xtra) sample?

Rockpanel board material is not only fire safe but also holds many more unique properties for your project.

Get your free Rockpanel A2 (FS-Xtra) sample

More information on Fire Safety