Part 10.3:Fire behaviour of HPL products

Reaction-to-fire
HPL-panels with a minimum thickness of 6 mm usually reach class D-s2,d0 without any flame retardant. HPL-panels produced in a flame retardant version are usually classified B-s2,d0. This is the best class possible for this type of material. HPL-similar products with decorative surfaces and an anorganic, non-combustible core even reach class A2-s1,d0 according to the European classification scheme. Classification Reports for all three variants are known by the Testing Centre, Inspection and Certification Services of the City of Vienna.

Fire spread
Typical rear-ventilated systems consisting of:

• stone wool as insulation material 
• a metal substructure
• a ventilation gap with no more than 60 mm width 
• flame-retardant HPL panels as cladding (minimum thickness 6 mm), mechanically fastened onto the substructure
• usually pass the medium and large-scale tests given in table 1a-1b 

Very often the system has to include additional structural fire protection measures such as horizontal fire barriers, non-combustible window reveals etc. to pass these tests.