Fireproof Sealing Instructions for Cable Trays

Cable trays should be sealed using certified firestop systems such as intumescent coatings, fire wraps, or fireproof pillows to maintain fire integrity and prevent flame propagation. Key Fireproof Sealing Options1. Intumescent Coatings Intumescent coatings are reactive paints applied to cable trays that expand under heat to form an insulating char layer, slowing heat transfer and protecting cables during a fire.

They are typically factory-applied for consistent thickness and quality, making them ideal for new builds, hygiene-sensitive environments, and hazardous areas. These coatings are easy to inspect visually but require careful maintenance if damaged, as repairs must follow manufacturer guidelines to maintain fire integrity. 2.

Fire Wrap Systems Fire wraps involve multilayer passive barriers installed around the cable tray, often secured with stainless steel banding. They provide insulation and reflect radiant heat, making them suitable for retrofit projects, irregular routing, or outdoor installations. Wrap performance depends on proper installation, including seams, overlaps, and banding.

While wraps can be reopened for maintenance, reinstallation can be disruptive. 3. Fireproof Pillows (e.g., AF BAGS) Fireproof pillows are intumescent and ablative devices certified under EN 1366-3 for sealing cable tray penetrations up to EI 240.

They consist of a non-combustible fiberglass casing filled with intumescent compounds and thermal insulators. Pillows are easy to insert, reposition, and remove, making them ideal for maintenance or modification of cable systems. They are suitable for walls, floors, and non-conventional structures, providing a compact and effective fire seal even for cables up to 21 mm in diameter.

Installation Considerations

Sealing gaps: All gaps around cables and trays must be tightly sealed without cracks or voids. For large openings, a fire-resistant backing plate may be required before sealing. Material selection: Choose fire-rated boards, mineral wool, firestop mastic, or firestop packs depending on the installation environment and regulatory requirements.

Compliance: Ensure the selected method restores the fire resistance of the building element to its original rating and meets relevant standards such as EN 1366-3. Maintenance: Fire wraps may require reinstallation after cable changes, while intumescent coatings and pillows allow easier inspection and repositioning.

Recommendation

For new installations, intumescent coatings provide a smooth, factory-controlled solution with minimal maintenance. For retrofits or irregular layouts, fire wraps offer flexibility and reflective insulation. For penetrations requiring easy maintenance or modification, fireproof pillows like AF BAGS are highly effective and certified for high fire ratings.

Selecting the appropriate method depends on installation type, regulatory compliance, and maintenance needs.