Fireproof sealing of suspended cable trays

Fireproof sealing of suspended cable trays can be achieved using intumescent pillows, firestop packs, sealants, or coatings, all designed to maintain fire integrity and prevent smoke and heat spread.Key Considerations

Purpose: Cable trays passing through walls, floors, or ceilings create potential fire paths. In a fire, cables can melt, leaving openings that allow smoke and flames to spread. Fireproof sealing ensures compliance with building regulations and maintains safety of electrical systems . Fire Ratings: Products are certified according to EN 1366-3 or ETA standards, providing fire resistance up to EI 240 minutes depending on the system and cable diameter .

Common Fireproof Sealing Solutions

1. Intumescent Fireproof Pillows (e.g., AF BAGS):
   • Contain intumescent compounds, thermal insulators, and water-release products inside a non-combustible fiberglass casing.
   • Suitable for cable diameters up to 21 mm for small penetrations, with sealing depth as low as 120 mm.
   • Can be repositioned for maintenance and are effective in walls, floors, and sandwich panels .
2. Firestop Packs and Mineral Wool:
   • Fire-resistant backing plates or mineral wool can be used for larger openings.
   • Gaps between packs and cables should not exceed 1 cm², and packing thickness should be at least 24 cm for reliable sealing .
3. Fire-Resistant Sealants:
   • Acrylic or graphite-based sealants are ETA-approved for single cables up to 21 mm and small bundles up to 50 mm.
   • Sealants are applied around cables to prevent smoke and flame passage while allowing some flexibility for cable movement .
4. Fire Protection Coatings and Tapes (e.g., FLAMMOTECT-A, DG-CR 0.7):
   • Provide a protective shield around cables and trays, preventing flame propagation.
   • Suitable for indoor and outdoor use, including industrial, hospital, and nuclear facilities.
   • Enhance resistance to environmental factors like UV, moisture, and chemicals .

Installation Guidelines

• Ensure floor and wall finishes are completed before sealing.
• Openings must be tightly sealed without visible cracks or voids.
• Layout should allow for future maintenance or cable modifications.
• Cover plates should be square, consistent in size, and painted evenly for aesthetic and safety compliance .

Maintenance and Compliance

• Fireproof sealing systems should be inspected periodically to ensure integrity.
• Modular systems like FIRSTO or SLIPSIL allow easy replacement or adjustment without compromising fire safety .
• Always select products with proper certification (EN 1366-3, ETA) to meet local building codes and fire safety regulations . By combining the appropriate fireproof pillows, sealants, or coatings with correct installation practices, suspended cable trays can be effectively protected against fire, ensuring both safety and regulatory compliance.