Fireproof sealing of parallel cable trays penetrating walls

Parallel cable trays penetrating walls should be sealed using certified firestop systems, intumescent pillows, or modular fireproof packs to maintain fire resistance and prevent smoke spread.Key Principles

1. Firestop Materials Use fire-rated materials such as firestop boards, mineral wool, firestop mastic, or intumescent pillows to seal gaps around cable trays. The materials must be compatible with the wall type and rated for the required fire resistance (e.g., EI 120–240) and mechanical load .
2. Installation Techniques
   • For large openings, install a fire-resistant backing plate before sealing .
   • Firestop packs or pillows should be placed in an orderly sequence, ensuring gaps between packs and cables do not exceed 1 cm², with a minimum packing thickness of 24 cm for larger penetrations .
   • Modular systems like FIRSTO allow easy assembly around multiple cable trays and facilitate future cable additions or removals while maintaining fire protection .
   • AF BAGS are intumescent pillows that can be inserted into thin walls or sandwich panels, providing up to EI 240 protection for cable diameters up to 21 mm .
3. Sealing Requirements
   • Ensure tight and complete sealing around all cable trays, both internally and externally, without visible cracks or voids .
   • Cover plates should be square, evenly painted, and properly dimensioned to close the opening securely .
   • Maintain adequate clearance between cables to prevent heat accumulation and allow airflow, especially in perforated or wire mesh trays .
4. Inspection and Maintenance
   • Periodically inspect seals for integrity, corrosion, or mechanical damage .
   • Verify that grounding continuity is maintained and that firestop materials remain properly positioned .
   • Fireproof systems should be checked according to manufacturer guidelines and local building authority regulations .
5. Compliance and Certification
   • Use products certified under standards such as EN 1366-3 or approved by local building authorities .
   • Ensure the firestop system is suitable for the wall type, penetration size, and number of cable trays .

Recommended Products and Systems

• FIRSTO Modular Firestop System: Flexible, easy to install, supports multiple cable trays, and withstands mechanical loads .
• AF BAGS Intumescent Pillows: Certified for EI 120–240, suitable for thin walls and sandwich panels, easy to reposition for maintenance .
• Flamro Penetration Seals: Approved systems for various cable types and mixed penetrations, compliant with building authority regulations . By following these guidelines, parallel cable trays can safely penetrate walls while maintaining fire resistance, preventing smoke spread, and allowing for future modifications or maintenance.