Fire-retardant coating for galvanized cable trays

Fire-retardant coatings such as FLAMMOTECT-A, DG-CR 0.7, and SikaSeal®-641 are effective solutions for enhancing the fire resistance of galvanized cable trays.

Recommended Fire-Retardant Coatings

1. FLAMMOTECT-A and DG-CR 0.7 These products are designed to protect cables and cable trays in high-risk environments, including hospitals, industrial plants, and offshore facilities. They form a robust protective shield that prevents flame propagation and maintains cable functionality during fire events. In addition to fire protection, they enhance resistance to UV radiation, moisture, salt water, oil, and chemicals, making them suitable for both indoor and outdoor galvanized trays . 2. SikaSeal®-641 Fire Coating This is a water-based ablative coating specifically developed for grouped or bundled cables and cable trays. It complies with IEC 60332 (Cat. A) and IEC 60331 fire tests. The coating is applied at a recommended film thickness of approximately 2.5 mm wet, resulting in 1.6 mm dry, with effectiveness directly related to thickness. It can be applied over galvanized trays after cleaning dust or grease, and it is suitable for both indoor and outdoor installations . 3. Fire-Retardant Composite Boards Some manufacturers offer galvanized composite fire-retardant boards that integrate a fire-resistant layer with the structural tray. These solutions provide passive fire protection, forming an insulating barrier during fire exposure and reducing flame spread. They are particularly useful in high-risk or high-rise building applications where fire safety is critical .

Application and Installation Considerations

• Surface Preparation: Remove dust, grease, or oil from galvanized trays before applying coatings. Light cleaning is sufficient for most coatings, while heavy contamination may require washing or dry wiping .
• Film Thickness: Ensure the recommended thickness is achieved, as fire resistance is directly proportional to coating thickness .
• Tray Type Compatibility: Hot-dip galvanized trays are commonly used, but their zinc coating melts at relatively low temperatures. Applying a fire-retardant coating significantly improves fire performance .
• Environmental Resistance: Choose coatings that withstand UV, moisture, and chemical exposure for outdoor or industrial installations .
• Maintenance: Periodically inspect coated trays for integrity, corrosion, or damage to ensure long-term effectiveness .

Standards and Compliance

Fire-retardant coatings for cable trays should comply with relevant IEC fire tests and local building codes. Products like SikaSeal®-641 and FLAMMOTECT-A have documented certifications for fire performance, ensuring compliance with safety regulations .

Summary

For galvanized cable trays, water-based ablative coatings (SikaSeal®-641), intumescent coatings (FLAMMOTECT-A), and fire-retardant composite boards are effective solutions. Proper surface preparation, correct film thickness, and periodic inspection are essential to maintain fire protection performance. These coatings not only enhance fire resistance but also protect against environmental factors, ensuring reliable operation of cable systems in critical installations.