When it comes to fire safety in façade cladding, the distinction between non-combustible and combustible building materials is a very important one. The level of combustibility in façade cladding is one of the factors that determines their fire classification.
What does non-combustible mean?
Non-combustible simply means that a material does not contribute to a fire. The gradation of non-combustibility is determined by the Euroclass system, where classes A1 and A2 are non-combustible and B-F combustible.
When you use non-combustible materials, you basically design out the risk, because this material does not significantly contribute to a fire. When you’re using non-combustible façade cladding that is installed correctly and combines with other non-combustible building materials, façade cladding is a very safe option. The non-combustibility (A1, A2) is secured by setting limits to the calorific content (PCS values). For combustible materials (B-F) these limits are not set.
What are combustible materials?
Combustible materials have a higher calorific value than non-combustible materials and can therefore contribute to the spread of a fire. In the Euroclass system, classes B to F are combustible.
It is important to note the meaning of the different Euroclass classifications. A Euroclass B classified board close to the A2 border is much safer than a Euroclass B board which is much further from that border. Of course, lower classifications (Euroclass C to F) are even less fire safe. An F classification even means the material hasn’t managed to pass any of the tests for a higher class.
For high-rise and high-risk buildings, we advise to always use non-combustible materials.
Want to find out more about commonly used terms in firesafe building? Check out our complete fire terminology dictionary.
