Fire cable tray thickness

Fire-rated cable trays typically use aluminum, galvanized steel, or stainless steel with side rail thicknesses ranging from 0.060 in (1.5 mm) to 0.10 in (2.54 mm) depending on material and load requirements.

Material Selection

• Indoor environments: Painted steel or galvanized steel trays are commonly used.
• Outdoor or corrosive environments: Hot-dip galvanized steel, stainless steel, aluminum alloy, or fiberglass-reinforced plastic trays are preferred for corrosion resistance and durability .
• Aluminum trays: Lightweight, corrosion-resistant, and suitable for areas with minimal heat buildup .

Thickness and Dimensions

• Aluminum trays: Side rails typically range from 0.065 in (1.65 mm) to 0.10 in (2.54 mm) for open-ladder designs .
• Galvanized steel trays: Minimum thickness is usually 0.060 in (1.5 mm) for structural integrity .
• Tray width and depth: Common maximum dimensions for fire-rated installations are 24 in (610 mm) wide and 6 in (151 mm) deep, with a maximum cable loading depth of 5 in (127 mm), .

Fire and Safety Considerations

• Maintain minimum annular space of 2 in (51 mm) between trays and wall openings to ensure firestop effectiveness .
• Aggregate cable cross-sectional area should not exceed 45% of the tray's cross-sectional area to prevent overheating .
• Use rigid supports on both sides of wall assemblies and ensure proper grounding continuity at each connection point .

Installation Guidelines

• Horizontal deviation should be ≤2 mm per meter and vertical deviation ≤3 mm per meter to maintain level and plumb installation .
• Use dedicated splice plates and bolts for secure connections.
• Remove sharp edges or debris inside the tray to prevent cable damage .
• Segregate power and signal cables to minimize electromagnetic interference .

Summary

For fire-rated cable trays, aluminum or galvanized steel is standard, with side rail thicknesses from 1.5 mm to 2.54 mm depending on material and load. Proper spacing, support, and adherence to firestop and grounding requirements are essential to maintain safety and compliance with fire protection standards .