Fire-resistant base plate for cable trays

Fireproof cable trays should use fire-support or fire-resistant backing plates, typically made of metal or fire-rated board, installed at slab penetrations or wall openings to maintain fire integrity. Recommended Base Plate TypesFire-support plates are commonly used at slab penetrations to provide a stable, fire-resistant base for cable trays. These plates can be made of galvanized steel, stainless steel, or fire-rated board materials and are installed beneath or around the tray to support firestopping materials and prevent heat transfer to structural elements.

For large openings, a fire-resistant backing plate is recommended before sealing with firestop mastic, mineral wool, or firestop packs. Key characteristics of suitable base plates: Material: Metal (galvanized or stainless steel) or fire-rated boards that can withstand high temperatures. Dimensions: Plates should cover the opening completely, with consistent, square dimensions to ensure proper sealing.

Thickness: Sufficient to support the tray and firestop materials; typically, firestop packing thickness is at least 24 mm. Surface treatment: Painted or coated evenly to prevent corrosion and maintain fire resistance.

Installation Considerations

Sealing: All gaps around the tray and base plate must be tightly sealed with firestop materials to prevent flame and smoke spread. Alignment: Plates should be positioned to facilitate installation and maintenance, ensuring the tray remains level and stable. Compatibility: Use base plates that are compatible with the tray type (ladder, perforated, or solid) and the firestop system tested for that configuration.

Additional fireproofing: For critical services, consider wrapping trays with insulation or using fire-rated enclosures in addition to base plates.

Summary

For fireproof cable trays, use fire-support or fire-resistant backing plates made of metal or fire-rated board, properly sized and installed at slab or wall penetrations. Ensure all gaps are sealed with approved firestop materials, and follow manufacturer guidelines for tray type and fire rating to maintain compliance and safety.