Fire-resistant coating material for cable trays

Intumescent and ablative coatings are the primary fire-resistant materials for cable trays, providing insulation, flame retardancy, and circuit integrity during fire events.

Types of Fire-Resistant Coatings

Intumescent Coatings: These are reactive paints that expand when exposed to heat, forming an insulating char layer that slows heat transfer and prevents flame propagation. Products like ALTIC 007 provide up to 4 hours of certified circuit integrity, are water-based, halogen-free, and resistant to water, oil, alkali, and UV radiation, making them suitable for both indoor and outdoor applications (ALTIC 007) . Intumescent coatings are ideal for new builds, hygiene-sensitive environments, and hazardous areas, and factory application ensures consistent thickness and performance . Ablative Coatings: Water-based ablative coatings, such as SikaSeal®-641, are designed for grouped or bundled cables and cable trays. They form a protective layer that chars under fire, reducing heat transfer. Effectiveness depends on film thickness, typically around 2.5 mm wet film thickness, resulting in ~1.6 mm dry film thickness. These coatings are suitable for IEC 60332 and IEC 60331 fire tests and can be applied on clean cables without extensive preparation . UL Classified Coatings: UL classified cable tray coatings are evaluated under specific UL standards for fire performance. They help limit flame propagation and improve fire performance of cable installations, particularly in critical facilities like power plants, data centers, and industrial plants. Selection requires reviewing the product's UL certification, test standards, and installation requirements .

Alternative Solutions

Fire Wrap Systems: Passive protection using multilayer fire barriers secured with stainless steel banding. Often aluminized to reflect radiant heat, fire wraps are suitable for retrofit projects, irregular routing, and harsh sun exposure. Wraps are workmanship-dependent and may require reinstallation during cable changes, but they can be cost-effective for certain applications .

Key Considerations

• Application Method: Factory-applied coatings ensure uniform thickness; site-applied wraps may require careful installation.
• Environmental Resistance: Coatings should resist UV, moisture, chemicals, and temperature variations.
• Certification and Testing: Verify compliance with IEC, ASTM, NFPA, or UL standards for fire endurance.
• Maintenance and Inspection: Coatings are easier to inspect visually, while wraps may need rework after modifications.

Conclusion

For new installations, intumescent or ablative coatings are generally preferred due to consistent performance, ease of inspection, and suitability for hazardous or hygiene-sensitive areas. For retrofits or irregular cable routing, fire wrap systems may be more practical. Always ensure the selected material meets project-specific fire ratings, environmental conditions, and regulatory standards to maintain cable integrity and safety during fire events .