Fireproof sealing is required inside the cable tray

Yes, fireproof sealing is required for cable trays where they pass through walls, floors, or slabs to prevent fire and smoke propagation.Importance of Fireproof Sealing

Cable trays often penetrate walls, floors, or slabs in electrical installations. Without proper fireproof sealing, these openings can allow fire and smoke to spread rapidly, compromising building safety and critical systems. Firestopping ensures that the integrity of fire-rated barriers is maintained and that cables remain functional during a fire .

Fireproofing Methods and Materials

Fireproof sealing can be achieved using a variety of materials and techniques:

• Firestop Packs and Pillows: Intumescent or ablative pillows, such as AF BAGS, expand under heat to seal cable tray penetrations and are certified under EN 1366-3 for up to EI 240 fire resistance .
• Firestop Mastic and Caulks: Intumescent caulks like IC 15WB can seal gaps around cables and trays, blocking heat and smoke penetration .
• Fire-Resistant Boards and Mineral Wool: Used for larger openings, often combined with backing plates to ensure complete sealing .
• Fire Protection Coatings and Tapes: Products like FLAMMOTECT-A and DG-CR 0.7 provide a protective shield around cables and trays, suitable for indoor and outdoor applications .

Installation Guidelines

• Ensure all gaps inside and around the cable tray are sealed tightly, without visible cracks or voids .
• For slab penetrations, provide 20–30 mm of firestopping and install a fire-support plate at the top .
• Firestop packs should be placed in an orderly sequence, with gaps between packs and cables not exceeding 1 cm² and packing thickness not less than 24 cm .
• Cover plates should be square, consistent in size, and painted evenly to close the opening .
• Only use fireproof trays for flame containment or isolation; do not modify or damage the tray coating during use .

Maintenance and Inspection

• Periodically inspect fireproof trays and sealing materials for corrosion, deformation, or damage .
• Ensure tray connections are firm, straight, and properly aligned, and confirm grounding continuity .
• Fireproof seals should be checked regularly to maintain long-term effectiveness and compliance with fire safety standards . In summary, fireproof sealing inside cable trays is essential wherever they penetrate fire-rated structures. Using certified materials and following proper installation and maintenance procedures ensures both fire safety and operational reliability of electrical systems.