Thickness of fireproof cable tray board

The thickness of a fireproof cable tray should be selected based on cable load, mechanical strength requirements, and fireproof coating standards, typically ranging from 1. 2 mm to 3 mm for steel trays, with additional fireproof coating thickness as specified by national standards.

Mechanical and Load Considerations

The tray thickness must support the number and weight of cables without deformation or failure under full load. Heavier cable bundles require thicker trays to maintain structural integrity. Ensure that the tray is level, plumb, and securely mounted on supports, with deviations not exceeding 2 mm per meter horizontally and 3 mm per meter vertically.

Fireproof Coating Thickness

Fireproof cable trays often require a fire-resistant coating applied over the metal tray. The coating thickness should meet national safety standards and project specifications, typically measured using calibrated devices. Uniform application is critical to achieve the required fireproof grade, and inspection should confirm adhesion, absence of cracks, and consistent coverage.

Firestopping at PenetrationsAt slab or wall penetrations, fireproofing may require additional packing or backing plates, with recommended firestop thicknesses of 20–30 mm and packing thickness not less than 24 mm to ensure complete sealing and prevent fire spread.

Material Selection

Steel trays are commonly used for fireproof applications, with thicknesses generally ranging from 1. 2 mm to 3 mm depending on load and span. Aluminum trays may require different thicknesses due to lower mechanical strength but offer corrosion resistance.

Summary

Tray base thickness: 1. 2–3 mm for steel, adjusted for load and spanFireproof coating: As per national standards, uniformly appliedFirestopping at penetrations: 20–30 mm with backing plates and packing ≥24 mmInstallation: Ensure level, plumb, and secure mounting with proper grounding Selecting the correct thickness ensures both mechanical stability and fire safety, complying with regulatory requirements and extending the lifespan of the cable tray system.