Fireproof coating thickness requirements for cable trays

The recommended fireproof coating thickness for cable trays typically ranges from 1.2 mm to 1.6 mm dry film thickness (DFT), depending on the product and application method.

Typical Thickness Guidelines

• SikaSeal®-641 Fire Coating: For cable trays, the recommended wet film thickness (WFT) is ~2.5 mm, which results in a dry film thickness (DFT) of approximately 1.6 mm. Coverage should be increased by about 30% for grouped cables or curved surfaces to ensure uniform protection .
• Flame Cabel Coating: A minimum coating thickness of 1.2 mm is recommended along the cable length, ensuring complete coverage and fire protection .
• Other Fireproof Coatings: Some products, such as those used in penetration seals or applied over mineral wool, may have similar DFT requirements around 1.2–1.6 mm, depending on the fire rating and insulation properties .

Application Considerations

• Surface Preparation: Clean the cable tray and cables thoroughly to remove dust, grease, or rust to ensure proper adhesion .
• Application Method: Coatings can be applied by spraying, brushing, or rolling. Spraying is often preferred for uniform coverage .
• Inspection: Use calibrated devices to measure coating thickness and verify compliance with project specifications and national fire safety standards . Check for cracks, peeling, or uneven surfaces. Adhesion tests may also be required.
• Environmental Conditions: Apply coatings within the recommended temperature range (typically +5°C to +30°C) and allow proper drying time to achieve the specified DFT .

Key Points

• The effectiveness of fireproof coatings is directly related to thickness; insufficient thickness can compromise fire resistance.
• Always follow the manufacturer's technical datasheets and national fire safety standards for the specific coating product.
• Regular maintenance and inspection are recommended to ensure long-term fire protection and durability of the cable trays . By adhering to these thickness guidelines and application practices, cable trays can achieve the required fire resistance and comply with safety standards.