What's the fire resistance rating of the exterior fire?retardant?coating?
First of all, fire retardant coating has no class distinctions. Buildings fire resistance rating is generally classified as follows: I grade fire resistance, II grade fire resistance, III grade fire resistance, IIII grade fire resistance. Buildings with I grade and II grade fire resistance are much common. According to the coating thickness, exterior fire-resistant coating for steel structure can be classified as follows: 1. Exterior thin fire-resistant coating for steel structure, 2. Exterior ultra-thin fire-resistant coating for steel structure, 3. Exterior thick fire-resistant coating for steel structure.
Exterior thick fire-resistant coating for steel structure can reach the first level of fire resistance, thin fire-resistant coating for steel structure can be fire-resistant for three hours, and ultra-thin fire-resistant coating for steel structure can just be within the second level of fire resistance.
Current fireproofing material is mainly classified into five grades: A class: Incombustible building material which is almost incombustible. A1 class: It is noncombustible and cann't cause open fire. A2 class: It is noncombustible but needs to measure the smoke it will cause and that should be qualified. B1 class: Flame-retardant building materials: Good in fire retardation, it is non-combustible when meeting open fire in the air or under high temperature, and it is difficult for the fire to spread quickly. Besides, when the fire source is removed, combustion stops immediately. B2 class: Combustible building material: It has certain fire retardation. In the case of open fire in the air or at high temperature, it will immediately burst into flames, and easily lead to the spread of fire, such as the spread to wooden pillars, timber roof truss, timber beams, wood stairs, etc. B3 class: Flammable building material has no fire retardation effect at all. It is highly combustible with big fire risk. Besides, the classifications of fire resistance rating of building materials are different according to different standards: dDIN4102: A1, A2, B1, B2, B3; x0dEN13501-1: A1, A2, B, C, D, E, F. Hope it helps.
