Fireproof sealing of multi-level cable trays

Multi-level cable trays can be effectively fireproofed using modular firestop systems, intumescent pillows, or sealants that comply with EN 1366-3 or UL standards. Key Fireproofing Methods1. Modular Firestop Systems Products like CSD FIRSTO® firestops use a metal frame encompassing the entire cable run or tray at the penetration point.

Fire-resistant cellular rubber inter-layered with intumescent pads provides a UL-classified firestop for up to four hours, accommodating any cable size or quantity. These systems can be installed before or after tray and cable installation, allowing easy maintenance and modifications without additional parts. 2.

Intumescent Fireproof Pillows AF BAG

S are intumescent and ablative pillows certified under EN 1366-3 for sealing cable tray penetrations up to EI 240. They consist of a non-combustible fiberglass casing filled with intumescent compounds and thermal insulators. The pillows expand under heat, sealing gaps and containing fire spread.

They are suitable for walls, floors, and sandwich structures, and can be repositioned for maintenance. 3. Firestop Sealants and Packs For smaller gaps or irregular penetrations, firestop mastic, mineral wool, or firestop packs can be used.

Installation requires tight packing around cables, with gaps not exceeding 1 cm² and a minimum packing thickness of 24 cm. Large openings may require a fire-resistant backing plate before sealing. All gaps inside and around metal trunking must be sealed completely, both internally and externally.

Installation Considerations

Sequence: Ensure floor and wall finishes are complete, and shaft doors installed before firestopping. Support: At slab penetrations, provide 20–30 mm of firestopping and a fire-support plate at the top. Maintenance: Modular systems and pillows allow easy cable addition or removal without compromising fire integrity.

Material Selection: Choose materials compatible with the environment (e.g., wet, hazardous, or exterior conditions) and compliant with relevant standards. Compliance and StandardsEN 1366-3: Certification for fireproof pillows and penetration seals.

U

L Classification: Firestop systems like FIRSTO® provide UL-listed protection for walls and floors. Design Requirements: Ensure layout and positioning facilitate installation and maintenance while maintaining fire integrity.

Summary

For multi-level cable trays, modular firestop frames, intumescent pillows, and firestop sealants provide reliable fireproofing. Selection depends on cable size, tray configuration, penetration type, and environmental conditions. Proper installation ensures compliance with fire safety standards, maintains accessibility for maintenance, and effectively prevents fire and smoke propagation through cable penetrations.