How to distinguish the construction fire-proof material rating?
Currently the national standards divide building materials as follows: A1, A2, B, C, D, E, F. External wall thermal insulation fire?rating can be basically divided into: A1, A2, B1, B2, B3 and other levels. Class A is non-combustible, class B1 flame retardant, class B2 combustible, class B3 flammable. Combustion performance grades of building materials and products are divided into class A1, A2, B, C, D, E, F. And grading of flooring materials and pipeline thermal insulation materials is also stipulated separately, whose combustion performance grade is distinguished by the subscript fl and L respectively. ie. Combustion performance grades for ordinary building materials and products are A1, A2, B, C, D, E, F; combustion performance grades for paving material are Alfl, A2fl, Bfl, Cfl, Dfl, Efl, Ffl; combustion performance grades for pipeline thermal insulation material are A1L, A2L, BL, CL, DL, EL, FL.
Each country has its own fireproof standards, so I do not know which country you are in ? Each country has different division levels of fireproof materials, such as GB 8624, German standard DIN 4102-1, British standard BS 476, France standard NF P92-501 and so on. GB 8624 Chinese building materials and products combustion performance division levels fireproof resources network (FireTC.
According to national standard GB8624-97,combustion performance of building materials are divided into the following levels: Class A: Incombustible building material: Material that almost never burn. Class B1: Nonflammable building material: Nonflammable materials have good effect of flame resistance. In case of fire it in the air or at high temperature it is difficult to catch fire and spread, and when the fire source is removed, the combustion can stop immediately. Class B2: Combustible?building?material: Combustible materials have good effect of flame resistance. In case of open fire in the air or at high temperature, it will immediately burst into flames and spread the fire quickly, such as wooden column, timber roof truss, wooden stairs, etc. Class B3: Flammable building material: No flame-retardant effect, highly flammable, high risk of fire. According to national standard, the fire?rating of PVC floor must be class B1.
