Why are Water Based Steel Coatings so impressive?

Patrícia Gabriel / 28 June 2023

Water based intumescent steel coatings are a type of fire protection coating applied to structural steel elements to enhance their fire resistance. These coatings are designed to expand when exposed to high temperatures, forming an insulating char layer that helps to slow down the heat transfer to the steel substrate. This delay provides valuable additional time for evacuation, firefighting, and structural integrity during a fire incident.

Here are some key points to know about water based intumescent steel coatings:

  • Composition: Water based intumescent coatings typically consist of a combination of binders, fillers, flame retardants, and other additives. The binders, often based on acrylic resins, provide adhesion, and contribute to forming a protective layer when activated by heat.

  • Application: These coatings are typically applied using airless spray equipment, ensuring a smooth and uniform finish. Surface preparation, such as blating to clean and remove any rust or contaminants, is crucial to promote adhesion.

  • Thickness: The thickness of the coating is determined by the required fire resistance rating and is specified by the manufacturer based on product specific testing. Typically, intumescent coatings range from 250 microns to several millimetres in dry film thickness.

  • Expansion and Insulation: When exposed to heat, water based intumescent coatings undergo a chemical reaction that causes the coating to expand significantly. This expansion creates an insulating foam-like char layer, which protects the underlying steel from the heat of the fire.

  • Fire Rating: The fire rating of an intumescent coating refers to the duration of fire resistance it provides. Common fire rating classifications include 30 minutes, 60 minutes, 90 minutes, and 120 minutes. The specific fire rating required depends on building codes, occupancy type, and safety regulations.

  • Durability and Maintenance: Water based intumescent coatings offer good durability and weather resistance, making them suitable for both indoor and outdoor. However, periodic inspections and maintenance are essential to ensure their ongoing effectiveness.

  • Compatibility: Water based intumescent coatings are compatible with various substrates, including structural steel, concrete, and wood. They can be applied to beams, columns, walls, and other steel elements in commercial, industrial, and residential buildings.

  • Environmental Considerations: Water based coatings have lower volatile organic compound (VOC) content compared to solvent-based alternatives, making them more environmentally friendly. They also have reduced odour and pose fewer health risks during application.

  • Testing and Certification: Manufacturers subject their water based intumescent coatings to rigorous testing and evaluation to meet industry standards and regulatory requirements. Certifications from recognized organizations validate their performance and compliance with fire safety regulations.

It's important to consult with manufacturers, industry professionals, and local authorities to ensure the appropriate selection, application, and maintenance of water based intumescent steel coatings for specific projects, as requirements may vary based on local building codes and regulations.

Find out more about our Structural Steel Fire Protection range here!