Fireproof Sealing Solution for Cable Tray Openings

Cable tray openings can be effectively fireproofed using certified firestop systems such as intumescent pillows, firestop caulks, mineral wool, or modular sealing systems to maintain fire-resistance ratings.Key Principles

Fireproof sealing of cable tray openings ensures that fire and smoke cannot spread through walls, floors, or slabs where electrical cables pass. Openings must be tightly sealed without cracks or voids, and the sealing system should be compatible with the type of wall or floor construction and the cable tray dimensions .

Common Fireproofing Materials

1. Intumescent Firestop Pillows
   • Products like AF BAGS are certified under EN 1366-3 for up to EI 240 fire resistance.
   • They contain intumescent compounds and thermal insulators inside a non-combustible fiberglass casing.
   • Pillows are repositionable, allowing easy maintenance or modification of cable trays .
2. Firestop Caulks and Mastics
   • Intumescent caulks, such as IC 15WB, expand under heat to seal gaps around cables and trays.
   • Suitable for new construction or retrofitting, they can be applied with standard caulking guns .
3. Fire-Resistant Mineral Wool and Boards
   • Used for larger openings, often combined with backing plates to fill gaps and provide structural support.
   • Ensures complete sealing around metal trunking and cable trays .
4. Modular Firestop Systems
   • Systems like FIRSTO allow assembly around multi-cable or cable tray penetrations.
   • They provide mechanical load resistance and flexibility for adding or removing cables later .

Installation Guidelines

• Measure the opening and select the appropriate size and number of firestop elements.
• Install backing plates for large openings before sealing.
• Pack firestop materials in an orderly sequence, ensuring gaps around cables do not exceed 1 cm² and packing thickness meets product specifications .
• Seal all gaps inside and around metal trays, both internally and externally.
• Cover plates should be square, evenly painted, and securely fixed to close the opening.
• Follow UL or EN certifications for the specific wall or floor type to maintain the required fire-resistance rating .

Compliance and Safety

• Firestop systems must be tested and certified according to local building codes and standards.
• Proper installation ensures that fire-resistance ratings of walls and floors are restored, preventing fire and smoke from spreading through cable penetrations .
• Regular inspection and maintenance are recommended to ensure continued effectiveness, especially in high-traffic or renovation areas. By selecting the right certified firestop materials and following proper installation procedures, cable tray openings can achieve reliable fireproofing, maintain structural integrity, and comply with safety regulations.