How to fireproof and seal cables inside cable trays

Cables in trays should be protected using fire-resistant coatings, intumescent pillows, and approved penetration seals to prevent fire spread and maintain functionality. Fireproofing Cables in TraysFire-resistant coatings and tapes are commonly applied to cables to delay flame propagation and protect against heat damage. Products like FLAMMOTECT-A and DG-CR 0.

7 form a protective shield around cables, enhancing resistance to fire, UV radiation, moisture, and chemicals, and are suitable for both indoor and outdoor installations in industrial, commercial, and critical facilities such as hospitals or power plants. Tray selection and layout also contribute to fire safety. Use perforated or wire mesh trays to improve airflow and prevent heat accumulation.

Maintain adequate spacing between cables and segregate power and signal cables to reduce interference and overheating.

Sealing Cable Tray Penetrations

When cable trays pass through walls, floors, or slabs, openings must be sealed with fire-rated penetration materials to prevent fire and smoke spread. Approved solutions include: Intumescent fireproof pillows (e.g., AF BAGS): These expand under heat to seal gaps, certified for up to EI 240 protection, and can accommodate cables up to 21 mm in diameter. They are easy to reposition for maintenance and do not require additional framing.

Firestop packs, mastic, or mineral wool: Used for larger openings, ensuring gaps around cables do not exceed 1 cm² and packing thickness meets design requirements. Cover plates should be installed to close the opening neatly. Mortar or soft penetration seals: Suitable for mixed penetrations, ensuring compliance with building authority regulations and fire test standards.

Installation and Maintenance

Ensure trays are level, plumb, and securely mounted with minimal deviation (≤2 mm/m horizontal, ≤3 mm/m vertical) to maintain structural integrity. Inspect fireproof coatings, seals, and trays periodically for corrosion, damage, or degradation. Maintain grounding continuity and verify that fireproofing materials remain intact and effective over time.

Key Considerations

Only use fireproof trays and coatings for flame containment, not for unrelated functions. Ensure routine cleaning and fire resistance checks to maintain long-term effectiveness. Select materials compatible with environmental conditions (e.g., UV exposure, humidity, corrosive environments) to ensure durability.

By combining fire-resistant coatings, intumescent pillows, and proper penetration sealing, cable systems in trays can maintain operational integrity and prevent fire spread, meeting safety standards in critical installations.