Fire Classification explained for facade material specification

Author Martin Smithurst, EQUITONE Technical Manager UK

Fire classification for cladding materials is changing. While the facades industry expects and welcomes more stringent laws on materials, we look at what the current classifications means when specifying materials on buildings above 11m and 18m and the difference in legislation across the UK.

Here, we delve deeper into the meaning behind the EN 13501-1 fire classification. The information can help you to find the right materials to specify and gain confidence in your selection, while giving you a clearer picture of the standard of our EQUITONE fibre cement facade materials.

What does “reaction to fire” mean?

Reaction to fire focuses on the behaviour of the materials when exposed to heat or fire.

What is the European standard of fire safety?

The Euroclass system is recognised as the standard of fire safety across Europe. It classifies the reaction to fire, as well as evaluates multiple aspects such as ignitability, flame spread, heat release, smoke production and propensity for producing flaming droplets/particles.

The system was introduced by the European Union in 2000 to remove trade barriers between individual member states and ensure consistent quality levels. Our EQUITONE materials meet the European standard EN 13501-1.

How is the Euroclass system broken down?

The European classification standard EN 13501-1:2018 ranks construction materials in seven classes with regards to their fire behaviour: A1, A2, B, C, D, E and F.

The same document also gives a classification of these materials with regards to smoke development (s1, s2 and s3) and the formation of flaming droplets/particles (d0, d1 and d2).

Fire Classification explained for facade material specification

The designations are:

Fire Behaviour The reaction to fire classification determines how much a material contributes to the behaviour of fire. A2-s1,d0 is non-combustible in Scotland and of limited combustibility in England and Wales, while at the other end of the scale, an F rating is easily flammable.

A full breakdown can be found below:

A1 = non-combustible materials A2 = non-combustible (Scotland) and limited combustibility (England and Wales) B, C, D = ranges from very limited to medium contribution to fire E, F = high contribution to fire A2 materials and above, which includes EQUITONE, can be safely used in buildings over 18 metres, as stated in the government's Approved Document B – a building regulation in England covering fire safety matters within and around buildings.

The same rule currently applies in Scotland. However, the guidance for the minimum building height at which non-combustible cladding – classified as A2 materials and above – is to be provided will be lowered to 11 metres with the revision of Scotland’s Building Standards Technical Handbook, which will apply from 1 October 2019.

Fire Classification explained for facade material specification

Smoke Development The ‘s’ part of the classification refers to the total smoke emitted during the first 10 minutes of exposure to fire:

S1 = little or no smoke S2 = quite a lot of smoke S3 = substantial/heavy smoke

Formation of Flaming Droplets/Particles The ‘d’ part of the classification relates to the number of flaming droplets and particles that are produced within the first 10 minutes of fire exposure. The index is below:

D0 = no droplets D1 = some droplets D2 = quite a lot

At EQUITONE we recognise the importance of understanding the characteristics and features of building materials when specifying them for your project.

With building material combustibility a key focal point during the specification stage, EQUITONE has a long-standing commitment to ensuring our fibre cement facade materials comprehensively meet the fire performance classification A2-s1,d0 to EN 13501-1:2018.