Common Problems Encountered During the Application of Fire‑Resistant Coatings for Steel Structures
2026-03-20
What problems arise in the use of fire‑proof coatings for steel structures? Do you know? Let the editor from Henan Huiquan Industrial Company explain it to you!
(1) Composition Issues: The film-forming substances in thin‑ and ultra‑thin fire‑retardant coatings are various organic resins or emulsions, while the intumescent flame‑retardant systems are predominantly based on a P–N system, comprising three key components: an acid source, a carbon source, and a gas‑generating agent. As evident from the typical constituents of these three components, while fire‑retardant coatings provide protective functionality, their flame‑retardant ingredients may release toxic gases. If the concentration of these gases exceeds the human body’s tolerance threshold, they can pose serious health risks to individuals who have not yet evacuated the fire scene as well as to firefighters engaged in suppression efforts.
(II) Durability Issues: Regardless of the type of fire‑protective coating, the fire‑resistance rating reported in its test certificate reflects the performance prior to application. In the author’s view, the durability of a fire‑protective coating encompasses two key aspects: first, the long-term adhesion of the coating—specifically, the bond between the coating and the substrate—and whether phenomena such as delamination or chalking occur over time; second, the sustained fire‑protective performance—namely, whether the fire‑resistance rating diminishes after several years, a concern that is often more insidious than the former. For thin‑ and ultra‑thin‑type steel‑structure fire‑protective coatings dominated by organic components, whether applied indoors or outdoors, these organic constituents are susceptible to decomposition, degradation, and aging, which can lead to coating delamination, chalking, or loss of fire‑protective efficacy.
(3) Proper Selection of Fire‑Resistant Coatings Having been engaged in the supervision and testing of fire‑resistant coatings for steel structures for many years, the author has observed several issues in the proper selection of such coatings in actual projects. These can be broadly categorized into three situations: First, there is confusion between interior‑use steel‑structure fire‑resistant coatings and exterior‑use coatings that offer superior resistance to water, freeze–thaw cycles, aging, and high mechanical strength. Second, some designers mistakenly assume that the fire‑resistance duration of a coating is directly proportional to its thickness, believing that simply increasing the coating thickness will proportionally extend its fire‑resistance time. Consequently, they erroneously apply ultra‑thin coatings to load‑bearing steel members where the required fire‑resistance limit exceeds 1.5 hours. Third, there is a failure to distinguish between decorative‑finish fire‑resistant coatings and structural fire‑resistant coatings, resulting in an inability to achieve a substantial increase in the fire‑resistance rating of the steel structure.
(4) Product Quality and Market Issues At present, the fire‑protective coating market is in a state of disorder, with widespread counterfeiting and substandard products. Illegal production and sales, cutting corners on materials, and passing off fakes as genuine are particularly prevalent. Unregulated competition has allowed large quantities of inferior fire‑protection products to enter construction projects, creating hidden risks to construction quality and posing a serious threat to public safety. Currently, steel‑structure fire‑protective coatings face significant problems in both product quality and market practices, including substituting inferior materials during testing, using substandard products in manufacturing, skimping on materials during installation, inadequate regulatory oversight, and insufficient enforcement of project supervision.
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