What fireproof sealing material should be used for cable trays

Intumescent sealants, fireproof pillows, and fire-resistant coatings are commonly used to seal cable tray penetrations and prevent fire and smoke spread.Intumescent SealantsIntumescent sealants, such as Pyroplex Pressure Exerting Sealant, expand when exposed to high temperatures, filling gaps around cable trays and bunched cables to block fire and smoke. They are suitable for internal use, around metallic services, and small plastic pipes up to 55 mm in diameter. For cable tray applications, these sealants are often used in combination with a fire-resistant coating to enhance protection. They provide fire resistance up to 240 minutes, are halogen-free, and adhere well to common building materials, making them ideal for tight penetrations and irregular shapes (Pyroplex) .Fireproof PillowsAF BAGS are intumescent and ablative fireproof pillows certified under EN 1366-3 for sealing cable tray penetrations. They consist of a non-combustible fiberglass casing filled with intumescent compounds and thermal insulators. These pillows can be inserted into walls, floors, or sandwich panels, providing protection up to EI 240. They are easy to reposition, making them suitable for maintenance or modifications, and are effective for cables up to 21 mm in diameter with a sealing depth of 120 mm .Fire Wraps and Intumescent CoatingsFire wrap systems involve multilayer barriers installed around cable trays, often with reflective facing to reduce radiant heat. They are suitable for retrofit projects or irregular routing. Intumescent coatings are reactive paints applied to cable trays that expand under fire to form an insulating char layer. Coatings are ideal for new builds and hygiene-sensitive environments, providing a smooth, cavity-free surface that supports inspection and maintenance. Both methods achieve certified fire endurance but differ in installation and lifecycle considerations .Firestop Packs and Mineral WoolFor larger openings or slab penetrations, firestop packs, fire-rated boards, or fire-resistant mineral wool can be used in combination with sealants to ensure complete firestopping. Gaps around cables should be tightly packed, with a maximum gap area of 1 cm² and a minimum packing thickness of 24 cm. Fire-resistant backing plates may be installed for additional support .Selection ConsiderationsApplication type: New build vs retrofit, indoor vs outdoor, or hygiene-sensitive areas.Cable size and tray configuration: Ensure the material accommodates the number and diameter of cables.Fire rating requirements: Choose materials certified for the required EI rating (e.g., EI 120–240).Maintenance and accessibility: Pillows allow repositioning, while coatings and wraps may require more effort for modifications.Environmental resistance: Consider UV, moisture, and chemical exposure for outdoor or industrial installations . In summary, intumescent sealants, fireproof pillows, and fire-resistant coatings are the primary fireproof sealing materials for cable trays. The choice depends on installation type, fire rating requirements, and maintenance considerations, often combining multiple solutions for optimal protection.