Fireproof sealing of fire cable trays

Fireproof sealing of cable trays is achieved using intumescent pillows, firestop caulks, mineral wool, or modular sealing systems to maintain fire resistance and prevent flame propagation through penetrations.

Key Methods and Materials

1. Intumescent Fireproof Pillows Intumescent pillows, such as AF BAGS, are designed to seal cable tray penetrations in walls, floors, and sandwich panels. They expand under heat to block fire and smoke, providing protection up to EI 240 according to EN 1366-3. These pillows are easy to install, repositionable for maintenance, and suitable for cables up to 21 mm in diameter with a sealing depth of 120 mm. They do not contain harmful fibers and can be used in thin or unconventional structures .

2. Firestop Caulks and Mastics Products like IC 15WB Caulk or intumescent latex/water-based caulks are applied around cable trays and cut edges to seal gaps. Their intumescent properties allow them to expand under heat, containing fire and smoke at the penetration point. They are suitable for both new construction and retrofitting existing installations .

3. Mineral Wool and Fire-Rated Boards For larger openings, fire-resistant mineral wool or fire-rated boards can be used as backing material before sealing. Firestop packs should be installed in an orderly sequence, ensuring gaps between cables and packs do not exceed 1 cm², and packing thickness meets design requirements (typically ≥24 cm). Cover plates should be square, evenly painted, and tightly fitted .

4. Modular Sealing Systems Systems like SLIPSIL, RISE®, and FIRSTO provide modular solutions for multi-cable or multi-pipe penetrations. These systems use expanding rubber inserts, sealants, or split frames to create fire, gas, and water-tight seals. They are particularly useful in industrial, marine, or offshore environments where high reliability is required .

Installation Considerations

• Ensure all gaps around cable trays are sealed without visible cracks or voids.
• For slab or wall penetrations, provide 20–30 mm of firestopping and install a fire-support plate at the top. Large openings may require a fire-resistant backing plate .
• Maintain accessibility for maintenance by using repositionable or modular solutions.
• Select materials certified to EN 1366-3 or equivalent standards to ensure compliance with fire safety regulations .

Additional Protection

Fire protection coatings and tapes, such as FLAMMOTECT-A or DG-CR 0.7, can be applied directly to cables within trays to enhance fire resistance and environmental durability, ensuring cables remain functional during a fire .

By combining these methods—intumescent pillows, firestop caulks, mineral wool, and modular systems—cable trays can be effectively sealed to prevent fire spread, maintain operational integrity, and comply with safety standards.