Fire performance classes
The reaction to fire performance of timber cladding is defined under EN 13501-1, and construction products are assigned a Euroclass rating under this system. The Euroclass system comprises ratings from A - F, and describes characteristics such as flame spread, ignitability, heat release, smoke production, burning droplets etc. The ratings system and examples of each category can be found in the table below.
|A1||Non-combustible||No contribution to fire||Glass/ Stone/ Concrete|
|A2||Limited combustibility||Very limited contribution to fire||Gypsum Boards with thin coverings (eg paper faced)|
|B||Combustible||Limited contribution to fire||Some flame retardant treated wood products*|
|C||Combustible||Minor contribution to fire||Some flame retardant treated wood products*|
|D||Combustible||Medium contribution to fire||Most wood based panels over 390kg/m³ in density*|
|E||Combustible||High contribution to fire||Some wood panel systems/ Plastic based insulation/ Composites|
Within the fire performance classes described above, further limitations of smoke and burning droplet production are taken into account in certain situations. This is normally applied to Euroclass A-D categories in specific circumstances, and would be written in the format Euroclass B-s1, d0.