Methods for sealing through cable trays

Cable tray penetrations can be sealed using firestopping materials, watertight gaskets, foam-based systems, and modular sealing frames to ensure safety, compliance, and environmental protection.

Firestopping Solutions

For cable trays passing through walls, floors, or slabs, firestopping is essential to prevent the spread of fire and smoke. Common methods include: Firestop packs and mineral wool: These are placed around cables or trays in the penetration, ensuring gaps are minimal (less than 1 cm²) and packing thickness meets design requirements. Firestop mastic or sealant: Applied to fill remaining voids and provide a continuous fire-resistant barrier.

Backing plates: Used for large openings to support firestop materials and maintain integrity. Modular firestop systems: Products like FIRSTO firestops allow assembly around multi-cable or cable tray penetrations, providing certified fire protection while remaining flexible for maintenance.

Watertight and Environmental Sealing

Cable trays may also require protection against moisture, dust, and chemical exposure: Weatherstop systems (WSP): Utilize steel frames with water-resistant pads and silicone-based sealants to create a watertight seal around cable trays.

SLIPSIL and NOFIRN

O systems: Self-compressing inserts and gaskets provide gas, water, and fire protection for single or multiple cable penetrations. FYLLOFOAM® and ACTIFOAM®: Lightweight, flexible foam-based solutions that expand under heat to maintain fire integrity while accommodating irregular or high-volume cable layouts.

Modular and Flexible Frame Systems

For retrofitting or complex installations: Split frame systems: Allow sealing around existing cables without removing them. Frames are placed around the tray with a gasket (e.g., NOFIRNO®) and attached to the wall or floor. Multi-entry seals: Designed to accommodate multiple cables through a single opening, reducing cutouts and simplifying layouts.

Right-angle or single-entry seals: Useful for tight spaces or individual cable penetrations, maintaining bend radius and minimizing leak points.

Installation Considerations

Ensure floor and wall finishes are complete before sealing. Maintain tight, crack-free seals both internally and externally. Select materials compatible with the environment (e.g., wet, hazardous, or outdoor conditions).

Plan for maintenance and cable changes, using systems that allow easy access without compromising the seal. By combining fire-rated materials, watertight gaskets, foam-based expansion systems, and modular frames, cable tray penetrations can be effectively sealed to meet safety, environmental, and regulatory requirements.