Cable Tray Fireproof Sealing Dimensions Diagram

Fireproof sealing for cable trays typically requires a packing thickness of at least 24 mm, gaps no larger than 1 cm², and sealing materials sized according to the tray width and cable diameters.

General Guidelines

• Packing Thickness: Firestop packs or pillows should have a minimum thickness of 24 mm to ensure adequate fire resistance, especially for slab or wall penetrations .
• Gap Tolerance: The gap area between the firestop material and cables should not exceed 1 cm² to prevent fire or smoke passage .
• Tray Opening Size: For ladder or solid-bottom trays, the firestop opening is typically 1.5 inches larger than the tray on all sides to allow proper placement of fireproof pillows or putty .

Product-Specific Dimensions

• AF Bags Fireproof Pillows:
  • Certified for small, medium, and large cable penetrations.
  • Small cables up to 21 mm diameter require a sealing depth of 120 mm.
  • The number and size of pillows should match the cable tray width and number of cables to fully close the penetration .
• 3M Moldable Firestop Pillows:
  • Medium self-locking pillows are used for openings sized 1.5 inches larger than the tray.
  • Example: A 4” x 12” tray would require a 7” x 15” opening for proper sealing .
• Roxtec Seals:
  • Frames and sealing modules are selected based on the exact cable tray dimensions.
  • Removable layers in the rubber modules allow adaptation to different cable diameters, ensuring a tight fit .

Installation Considerations

• All gaps inside and around metal trunking must be sealed completely, both internally and externally .
• Cover plates should be square, consistent in size, and painted evenly to close the opening.
• For large openings, a fire-resistant backing plate may be installed before sealing.
• At slab penetrations, a fire-support plate is recommended, with a waterstop of at least 50 mm at floor level .

Summary

To achieve effective fireproof sealing for cable trays:

1. Measure the tray width and cable diameters.
2. Select firestop pillows, packs, or seals that match or slightly exceed the tray dimensions.
3. Ensure packing thickness ≥ 24 mm and gap area ≤ 1 cm².
4. Use cover plates and backing plates as needed for large openings.
5. Follow product-specific installation instructions for depth, number of pillows, and arrangement to meet fire ratings up to EI 240 . This approach ensures compliance with fire safety standards and maintains the integrity of cable tray penetrations in walls, floors, and slabs.