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According to the national standard GB 8624-2012 "Classification of Combustion Performance of Building Materials and Products", external wall insulation materials are mainly divided into the following four levels based on their combustion performance:

Grade A: Non combustible material

Characteristics: It does not burn in a fire, does not spread flames, and has the highest fire safety.

Common materials: rock wool board, glass wool, foam cement board, foam ceramic board, etc.

B1 level: flame retardant material

Characteristics: It has good flame retardant properties and can self extinguish after leaving the fire source.

Common materials: specially treated polystyrene board (EPS), extruded polystyrene board (XPS), polyurethane board (PU), etc.

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B2 level: Combustible materials

Characteristics: It is easy to burn when the ignition source power is high, the flame propagation speed is fast, and the fire hazard is high.

Common materials: ordinary polystyrene board, extruded polystyrene board, polyurethane board, etc.

B3 level: flammable material

Characteristics: Extremely easy to ignite, flame propagation speed is extremely fast, and the fire hazard is extremely high. It is strictly prohibited to use it in the insulation system inside and outside the building.

Common materials: polyphenyl foam, etc.

Usage Specifications

According to the Code for Fire Protection Design of Buildings:

The internal and external insulation systems of buildings should use Class A insulation materials.

B2 level insulation materials should not be used.

It is strictly prohibited to use B3 level insulation materials.

Common types of insulation materials

In addition to being classified by combustion performance, exterior wall insulation materials can also be classified into the following categories based on their composition and purpose:

Organic thermal insulation materials: such as polyurethane foam and polystyrene board (EPS/XPS), with good thermal insulation performance but low fire resistance.

Inorganic insulation materials, such as rock wool board and glass wool, have good fire resistance but may be heavier.

Other new materials: such as phenolic foam, VIP board (vacuum insulation board), with special performance but high cost.

summary

When choosing external wall insulation materials, priority should be given to A-grade non combustible materials to ensure fire safety. At the same time, a comprehensive selection should be made based on factors such as insulation performance, construction conditions, and cost.