The standard thickness for fireproof cable tray cover plates is generally not less than 1 mm, with fire resistance typically required for at least 30 minutes.

Thickness and Fire Resistance

Fireproof cable tray cover plates are designed to prevent fire spread and protect cables during a fire. The minimum thickness of the cover plate is usually 1 mm, ensuring structural integrity under heat exposure, while the fire resistance limit is generally greater than 30 minutes for standard fire protection applications . Some designs use double-layer cover plates with a thermal insulation layer of approximately 25 mm to enhance fire resistance and ventilation .

Material and Construction

• Material: Steel or other incombustible, flame-retardant materials are preferred .
• Fireproof coating: Many fireproof cable trays include an internal fireproof coating that expands when exposed to fire, protecting the cables and tray structure .
• Design: Cover plates should be square, of consistent dimensions, and evenly painted to ensure complete closure of openings .

Installation Considerations

• Ensure tight sealing around the tray and cover plate to prevent gaps that could allow fire or smoke to pass .
• For slab penetrations, a fire-support plate of 20–30 mm thickness may be installed at the top, with waterstops of at least 50 mm height at floor-level penetrations .
• Proper installation sequence and use of firestop packs or mineral wool are recommended to maintain fireproof integrity .

Summary

For standard fireproof cable trays: cover plate thickness ≥ 1 mm, fire resistance ≥ 30 minutes, with steel or flame-retardant materials, optional double-layer plates, and proper fireproof coatings. Installation must ensure complete sealing and adherence to fire safety guidelines to maintain the tray's protective function .