Thickness of fireproof partition at cable tray opening

The recommended thickness for fireproof cable tray partitions typically ranges from 20 mm to 30 mm, depending on the material and fire-resistance requirements.Recommended Thickness and MaterialsFireproof partitions, also called fire-blocking sections, are installed in cable trays to prevent the spread of fire along the tray. For slab penetrations or electrical shafts, a firestopping layer of 20–30 mm is generally recommended, often combined with a fire-support plate at the top for added protection . The packing thickness for firestop materials, such as firestop packs or mineral wool, should not be less than 24 mm to ensure effective fire containment . Common materials used for fireproof partitions include:Fireproof boards: High strength, durable, and resistant to heat and corrosion .Fireproof coatings or mud: Easy to apply, good heat resistance, suitable for retrofitting .Fireproof bags or pillows: Convenient for filling gaps and irregular openings .Intumescent caulks: Expand under heat to seal gaps and prevent fire spread .Installation ConsiderationsEnsure tight sealing around all gaps inside and around the metal tray to prevent fire and smoke leakage .Use fire-support plates or backing plates for large openings to maintain structural integrity .Maintain mechanical strength of the tray and partitions to prevent deformation under cable load .Fire-blocking sections should be resistant to corrosion, water immersion, and rodent damage, especially in industrial environments .Practical NotesThe choice of partition thickness may vary depending on fire rating requirements, tray size, and the number of cables.Regular inspection and maintenance are recommended to ensure long-term fire protection performance.Lightweight fireproof sections are easier to install and maintain but may require more frequent checks, while high-strength boards provide durable protection but occupy more space . By following these guidelines, fireproof cable tray partitions can effectively isolate fire, protect power systems, and reduce potential damage in industrial and power facility environments.