Cable tray penetrations through walls must be sealed with fire-rated materials to prevent fire and smoke spread while maintaining accessibility and compliance with building codes.

Key Fireproof Sealing Methods

1. Firestop Materials: Openings around cable trays should be sealed using fire-rated boards, firestop packs, firestop mastic, or mineral wool. These materials are designed to withstand high temperatures and prevent fire propagation through wall penetrations. For large openings, a fire-resistant backing plate is recommended before sealing to ensure structural integrity and complete coverage . 2. Modular Firestop Systems: Products like FIRSTO firestops provide a modular solution for multi-cable and cable tray penetrations. They are easy to assemble around existing cable runs, allow for later cable additions or removals, and can withstand mechanical loads while maintaining fire and smoke containment . 3. Foam-Based and Intumescent Solutions: Flexible foam-based solutions such as FYLLOFOAM® and ACTIFOAM® expand under heat to maintain fire integrity around grouped cables. Intumescent caulks, like IC 15WB, expand when exposed to fire, sealing gaps and protecting structural elements and cable trays . 4. Certified Penetration Seals: Systems from providers like Flamro offer approved penetration seals for cable trays, conduits, and mixed penetrations. These products are tested to meet building authority regulations and restore the fire resistance of walls and floors after installation .

Installation Considerations

• Gap Management: Ensure gaps between cables and firestop materials do not exceed recommended limits (e.g., 1 cm² for firestop packs) and maintain sufficient packing thickness (e.g., ≥24 cm) for effective fire resistance .
• Accessibility: Modular and foam-based systems allow for easy retrofitting and cable maintenance without compromising fire protection .
• Mechanical Protection: Cover plates should be square, evenly painted, and securely installed to protect the firestop and maintain aesthetic and functional integrity .
• Compliance: Always use materials and systems that are tested and certified for fire resistance according to local building codes and standards .

Summary

To fireproof cable trays passing through walls, use certified firestop materials or modular systems that provide both fire and smoke protection. Consider intumescent caulks, mineral wool, or foam-based solutions for flexibility and ease of installation. Proper gap management, mechanical protection, and compliance with fire safety standards are essential to ensure effective fire containment and maintain building safety.