How thick should the fireproof partition for cable tray sealing be

The fireproof partition for cable tray sealing should be at least 10 millimeters thick.

Thickness and Dimensions

The minimum thickness of a fireproof bridge or partition should be 10 mm to ensure adequate fire resistance performance. The width of the partition should be at least equal to the width of the cable tray to effectively prevent fire spread. Additionally, the partition should be positioned at least 100 mm away from the edge of the tray to maximize its fire-blocking effectiveness .

Material and Fire Resistance

Fireproof partitions should be made from fire-resistant materials such as fire-rated boards, mineral wool, or intumescent components, which maintain stability under high temperatures and resist deformation, cracking, or burning . The fire resistance rating of the partition should not be lower than the fire resistance of the wall or floor it penetrates, typically 1 hour or more according to national standards .

Installation Guidelines

• Fixing: Secure the partition firmly to the tray using appropriate fasteners to prevent displacement .
• Observation: Include observation holes to monitor the internal condition of the tray if needed .
• Sealing: Ensure all gaps around cables and the tray are tightly sealed, with packing thickness for firestop materials generally not less than 24 mm for larger openings .
• Maintenance: Regularly inspect and maintain the partition to ensure integrity and continued fire protection .

Additional Considerations

For slab penetrations or large openings, it is recommended to install a fire-support plate and maintain a firestopping layer of 20–30 mm to enhance fire containment . Fireproof pillows or intumescent packs can also be used for flexible sealing in complex or thin structures, with typical sealing depths of 120 mm for cables up to 21 mm in diameter . By following these thickness and installation guidelines, fireproof partitions can effectively isolate fires, prevent fire spread along cable trays, and comply with safety standards.