Fireproof sealing method for the inside of cable trays

Fireproofing cable trays involves installing fire-blocking sections, using intumescent pillows or coatings, and sealing all gaps to prevent fire spread while maintaining cable integrity.

Fire-

Blocking Sections

To prevent fire propagation along cable trays, install fire-blocking sections (fire partitions) at regular intervals. These sections isolate different fire zones and reduce the risk of fire spreading through the tray system. Common materials include fireproof boards, fireproof coatings, fireproof bags, and fireproof mud, which are selected based on environmental conditions, durability, and fire resistance requirements.

Fire-blocking sections should maintain stability under high temperatures and comply with national standards for fire resistance, typically at least 1 hour.

Intumescent Products

Intumescent cable tray pillows are highly effective for sealing voids around metal or plastic trays. These pillows expand up to three times their original size when exposed to fire, filling gaps and locking together to prevent fire spread. They are easy to install, removable for maintenance, and provide up to 4 hours of fire protection.

Retention tags help secure them to the tray, ensuring proper placement.

Firestop Materials and Sealing

For tray penetrations through walls, floors, or ceilings, use fire-rated penetration sealing materials such as firestop mastic, mineral wool, or firestop packs. Ensure that all gaps inside and around the tray are tightly sealed without visible cracks or voids. Large openings may require a fire-resistant backing plate before sealing.

The gap area between firestop packs and cables should not exceed 1 cm², and packing thickness should meet design requirements.

Tray Material and Layout Considerations

Use fireproof or coated trays suitable for indoor or outdoor environments, such as painted steel, galvanized steel, or fiberglass-reinforced plastic. Maintain adequate spacing between cables to prevent heat accumulation and allow airflow, especially in perforated or wire mesh trays. Segregate power and signal cables to reduce interference and improve fire safety.

Inspection and Maintenance

Regularly inspect cable trays for corrosion, coating damage, or compromised fire-blocking sections. Replace or repair damaged fireproof materials promptly. Ensure tray connections are firm, aligned, and grounded to maintain both mechanical and fire safety.

Summary

To effectively fireproof and seal cable trays: Install fire-blocking sections at intervals to compartmentalize fire zones. Use intumescent pillows or coatings to seal gaps and expand during fire events. Apply firestop materials at penetrations and around cables, ensuring tight, void-free sealing.

Select appropriate tray materials and maintain proper cable spacing for heat dissipation. Conduct routine inspections and maintenance to ensure long-term fire protection effectiveness. These measures collectively enhance fire safety, protect cable integrity, and comply with building and electrical safety standards.