Fireproof sealing inside enclosed cable trays

Cable trays can be fireproofed using intumescent pillows, firestop packs, fire-resistant coatings, and proper sealing at penetrations to contain fire and heat.Fireproofing Inside Cable Trays1. Fire-Resistant Tray Materials and Coatings Use galvanized steel, stainless steel, or fire-resistant coated trays to enhance fire containment. Flame-retardant plastic composites can also be used, but surfaces should be coated with fire-retardant paint to slow flame spread and increase heat resistance. Fireproof coatings like FLAMMOTECT-A or DG-CR 0.7 tape provide additional protection against fire, UV, moisture, and chemical exposure, ensuring cables remain functional during a fire event . 2. Fire Barriers and Intumescent Products Install fire barriers within the tray to isolate different fire zones. For penetrations through walls or floors, use fire-rated penetration sealing materials. Products like AF BAGS are intumescent and ablative fireproof pillows certified under EN 1366-3, capable of sealing cable tray penetrations up to EI 240. They consist of a non-combustible fiberglass casing filled with intumescent compounds and thermal insulators, allowing insertion even in thin structures without additional framing . 3. Firestop Packs and Mastic For gaps around cables or trays, firestop packs, mineral wool, or firestop mastic can be used. Ensure the gap area between firestop packs and cables does not exceed 1 cm², and the packing thickness is sufficient (typically ≥24 cm for large penetrations). Cover plates should be square, evenly painted, and tightly fitted to prevent heat or smoke passage . 4. Installation GuidelinesRemove sharp edges or debris inside the tray to prevent cable damage .Lay cables neatly, avoiding twists and crossovers, and secure with ties or clips.Maintain adequate clearance between cables for heat dissipation; perforated or wire mesh trays improve airflow .Inspect tray connections, grounding continuity, and coating integrity regularly to ensure long-term fire resistance . 5. Heat Dissipation Considerations Fireproofing should not compromise airflow. Use perforated trays or maintain spacing between cables to prevent heat accumulation, which can reduce the effectiveness of fireproofing measures .SummaryEffective fireproof sealing of cable trays involves a combination of fire-resistant tray materials, intumescent pillows or packs, firestop mastic, and proper sealing at penetrations. Regular inspection and maintenance ensure that the fireproofing remains effective, while proper layout and heat dissipation measures prevent overheating and maintain cable integrity .