The steps for fireproofing and sealing cable trays

Fireproofing and sealing cable trays involves proper tray preparation, application of fire-resistant coatings, installation of firestop materials, and thorough inspection to ensure compliance and safety.

1. Planning and Tray Preparation

• Route Planning: Align cable trays with the building structure, avoiding unnecessary crossings or detours, and segregate power and signal cables to reduce interference ( ).
• Tray Selection: Choose trays based on environment—painted or galvanized steel for indoor use, hot-dip galvanized or stainless steel for outdoor, and aluminum or fiberglass-reinforced plastic for corrosive or high-humidity areas ( ).
• Surface Cleaning: Remove oil, dust, and rust using sandblasting, acid washing, or grinding to ensure proper adhesion of fireproof coatings ( ).

2. Fireproof Coating Application

• Primer Application: Apply a primer with strong adhesion and anti-corrosion properties uniformly across the tray surface ( ).
• Fireproof Coating: Use fire-resistant coatings that comply with national safety standards. Apply evenly using spraying, rolling, or brushing, controlling thickness to meet design specifications ( ).
• Topcoat: Apply a durable topcoat with weather-resistant and decorative qualities, ensuring a smooth, uniform finish without drips or bubbles ( ).

3. Firestopping and Sealing Penetrations

• Material Selection: Use fire-rated boards, firestop packs, firestop mastic, or fire-resistant mineral wool for sealing openings where trays pass through walls, slabs, or panels ( ).
• Installation: Place firestop packs in an orderly sequence, ensuring gaps between packs and cables do not exceed 1 cm² and packing thickness is at least 24 cm ( ).
• Sealing: Seal all gaps inside and around metal trunking tightly, both internally and externally. Cover plates should be square, evenly painted, and properly dimensioned ( ).
• Special Products: Intumescent caulks like IC 15WB or moldable putty can be used to contain fire and smoke at penetrations, protecting structural steel and cable trays ( ).

4. Inspection and Acceptance

• Coating Quality: Check for cracks, peeling, bubbles, and color consistency ( ).
• Thickness Verification: Measure coating thickness with calibrated devices to ensure compliance with fireproof grade requirements ( ).
• Adhesion Tests: Conduct cross-cut or pull-off tests to confirm secure bonding of coatings ( ).
• Fire Safety Tests: Perform combustion and endurance trials to verify fire resistance ( ).
• Documentation: Record inspection data, including dates, results, and responsible personnel signatures, for future reference ( ).

5. Maintenance

• Regular Inspection: Periodically check for wear, corrosion, or coating degradation.
• Repair: Reapply coatings or reseal penetrations as needed to maintain fireproof integrity ( ). By following these steps, cable trays will be properly fireproofed and sealed, ensuring long-term safety, compliance with standards, and protection against fire hazards.