Fireproofing and sealing of cable trays involves using intumescent coatings, firestop pillows, and certified sealing materials to prevent flame propagation and maintain cable functionality during a fire.

Fireproofing Cable Trays

Cable trays must be protected to ensure electrical safety and system reliability in case of fire. Fireproofing can be achieved using coatings, tapes, or fire-resistant materials that form a protective barrier around cables. Products like FLAMMOTECT-A coatings and DG-CR 0.7 fire protection tapes provide a robust shield against flames, heat, and environmental factors such as UV radiation, moisture, and chemicals, ensuring cables remain operational during a fire . These solutions are suitable for indoor and outdoor installations, including high-risk areas like hospitals, power stations, and industrial plants .

Sealing Cable Tray Penetrations

When cable trays pass through walls, floors, or slabs, openings must be sealed with firestopping materials to prevent fire and smoke spread. Common methods include:

• Intumescent fireproof pillows: Products like AF BAGS are certified under EN 1366-3 for up to EI 240 fire resistance. They expand under heat to seal gaps around cables, requiring minimal depth (e.g., 120 mm for cables up to 21 mm diameter) and are easy to reposition for maintenance .
• Firestop packs and mineral wool: For larger openings, a fire-resistant backing plate or mineral wool can be installed before sealing with firestop packs or mastic to ensure complete coverage .
• Moldable putty and caulks: UL-listed products like 3M Fire Barrier Moldable Putty or IC 15WB caulk adhere to metallic and non-metallic surfaces, expanding under heat to block smoke and fire while allowing retrofitting and reuse .

Installation Guidelines

• Tray layout: Keep cable routes short, straight, and segregated between power and signal cables to reduce interference and simplify maintenance .
• Tray material: Use galvanized or stainless steel for outdoor use, painted steel for indoor, and aluminum or fiberglass-reinforced trays in corrosive or high-humidity environments .
• Firestop placement: Ensure tight, crack-free sealing around all penetrations. Gaps between firestop packs and cables should not exceed 1 cm², and packing thickness should meet the rated fire resistance .
• Maintenance: Fireproof pillows and caulks should allow easy repositioning or replacement to accommodate cable modifications without compromising fire protection .

Compliance and Certification

All fireproofing and sealing materials should comply with relevant standards such as EN 1366-3, UL-listed systems, and local building codes. Proper documentation ensures that cable trays maintain rated fire resistance, supporting safe evacuation and continued operation of critical systems during a fire . By combining fire-resistant coatings, intumescent pillows, and certified sealing materials, cable trays can be effectively protected against fire, smoke, and heat, ensuring both safety and operational continuity.