Indoor non expanding steel structure fireproof coating

Indoor non expanding steel structure fireproof coating (often referred to as thick fireproof coating), applied to the surface of indoor steel structures, does not expand in the event of fire, relies on the low thermal conductivity and heat absorption and insulation of inorganic thick coatings, delays the heating of steel components, and ensures their bearing capacity is maintained in a fire.

🔍 core principle

Mainly composed of inorganic binders and lightweight insulation aggregates, it does not foam or expand when exposed to fire. The low thermal conductivity of the coating blocks heat transfer, while utilizing the heat absorption effect of component evaporation and decomposition at high temperatures to protect the steel structure from rapid heating.

📏 key parameters

-Coating thickness: usually 7-50 mm (GB 14907 is classified as thick type,>7 mm);

-Fire resistance limit: corresponding thickness can reach 1.5-3.0 hours, or even longer;

-Reference thickness: 1.5 hours approximately ≥ 10 mm, 2 hours ≥ 14 mm, 2.5 hours ≥ 19 mm, 3 hours ≥ 25 mm;

-Appearance and environmental protection: mostly gray white/cement color, rough surface, average decorative value; Most of them are asbestos free and solvent-free, with smoke toxicity reaching up to AQ1 level.

✅ Main Features

-Advantages: Non combustible, non-toxic, aging resistant, water-resistant and weather resistant, reliable durability, long fire resistance time, relatively economical cost;

-Shortcomings: The coating is thick, the decorative quality is poor, the texture is brittle, and the bonding force to the steel structure depends on physical anchoring. It is necessary to do a good job in crack prevention and detachment control.

🏗️ Applicable scenarios

Suitable for steel structures with high indoor fire resistance limit requirements (≥ 2 hours) and low decorative requirements, such as industrial plants, high-rise building beams and columns, large venues, petrochemical/power facilities, etc.

🛠️ Key construction points

Special spraying machinery is often used for dry spraying, and it can also be applied by wiping; Multiple applications are required to achieve the design thickness, followed by curing and solidification after construction to ensure bonding and insulation performance.