Cable tray through-wall sealing solution

Effective sealing of cable trays through walls requires fire-rated, smoke-resistant, and flexible solutions that maintain safety while allowing future cable modifications.

Key Considerations

When cable trays pass through walls, the openings can compromise fire and smoke compartmentation, creating potential hazards. Proper sealing ensures that flames, smoke, and hot gases cannot spread between compartments, protecting both personnel and infrastructure . Sealing must also accommodate high cable volumes and irregular tray shapes while remaining maintainable for future cable additions .

Firestop and Sealing Solutions

1. Foam-Based Firestops
   • Products like FYLLOFOAM® and ACTIFOAM® provide flexible, fire-rated sealing for grouped cables.
   • ACTIFOAM® expands under heat to maintain fire integrity around cables, making it suitable for irregular or hard-to-access penetrations .
2. Modular Firestop Systems
   • Systems such as FIRSTO allow modular assembly around cable runs, enabling easy installation and later cable additions or removals.
   • These systems prevent smoke and fire spread while withstanding mechanical loads, offering both safety and flexibility .
3. Seal Systems with Tray Inlays
   • Some patented solutions use compressible seal portions in tray inlays and covers to enclose cables tightly while allowing future cable placement.
   • This avoids the need to create new wall penetrations when adding cables, reducing construction risks and time .
4. Firestop Packs and Mineral Wool
   • For large openings, fire-resistant backing plates and firestop packs can be installed sequentially around cables.
   • Gaps should be minimal (less than 1 cm²), and packing thickness should meet fire-rating requirements (typically ≥24 cm) to ensure complete sealing .

Installation Best Practices

• Sequence: Install reserved openings → cable tray → cables → firestop materials → cover plates.
• Material Selection: Use fire-rated boards, firestop mastic, or mineral wool depending on wall type and fire-rating requirements .
• Maintenance Access: Choose systems that allow cable additions or replacements without compromising the seal .
• Mechanical Protection: Ensure the seal can withstand the weight and movement of cables, especially in vertical penetrations .
• Compliance: Follow local fire codes and standards for wall penetrations, including NEMA or ISO classifications where applicable .

Summary

Sealing cable trays through walls requires a combination of fire-rated materials, flexible modular systems, and precise installation. Foam-based and modular firestop solutions provide both safety and adaptability, while proper packing and backing plates ensure compliance with fire and smoke containment standards. Selecting the right system allows for future cable modifications without compromising the integrity of the wall penetration .