Although steel is not a burning body, it is easy to conduct heat and is afraid of fire. The fire resistance rating of buildings is one of the basic measures of fire prevention technology stipulated in the code for fire protection design of buildings. It requires that the basic building components such as walls, columns, beams, floors, roofs, stairs, ceiling, etc. can not be damaged or spread in a certain period of time under the continuous action of high temperature of fire.It plays the role of continuing or preventing the spread of fire.According to the actual situation in China, the fire resistance rating can be divided into 1, 2, 3 and 4.

     1、 Fire retardant coating for steel structure is a kind of important fire safety material. The construction quality of anti coating directly affects the fire performance and application requirements.According to the experience at home and abroad, the fire spraying construction of steel members should be undertaken by qualified professional construction team or under the guidance of engineering and technical personnel who develop fire retardant coating, so as to ensure the engineering quality.  

    2、 Generally, the steel structure shall be installed in place, and the suspender, raceway, pipe support and related components connected with it shall be installed and accepted before spraying.If the construction is carried out in advance and the steel member is hoisted after fire-proof spraying, the damaged coating and the node of steel member shall be sprayed after installation.

    3、 Before spraying, the surface of steel structure should be antirust, and the anti rust treatment standard should be determined according to the use requirements.Rust removal and fire prevention treatment shall comply with relevant provisions in code for acceptance of construction quality of steel structures (GB 50205-2011).For most steel structures, antirust primer should be applied, and there should be no chemical reaction between antirust primer and fireproof coating. 

    4、 Before spraying, the dust, oil stain and sundries on the surface of steel structure shall be removed.The 4-12 mm wide gap at the joint of steel members shall be filled and leveled with fire retardant coating or other fireproof materials.

    5、 The construction of fire retardant coating for steel structure shall be carried out before interior decoration and under the condition that it will not be damaged by later projects. During construction, the walls, doors and windows, machinery and equipment and other components that do not need fire protection shall be covered with plastic cloth.The coating just applied shall be protected from rain, dirty liquid pollution and impact of mechanical hard objects.  

    6、 For most fire retardant coatings, the ambient temperature should be kept at 5-38 ℃ and the relative humidity should not be greater than 90% during the construction and before the drying and curing of the coating, and the air should flow.When the wind speed is greater than 5m / s or after rain, it is not suitable to operate.The temperature and humidity of chemical curing and drying coatings can be relaxed. For example, LG steel structure fireproof coating can be applied at – 5 ℃.