Fireproof putty inside cable trays

Fireproof putty is used to seal cable tray penetrations, preventing the spread of fire and smoke while maintaining compliance with UL and European fire safety standards.

Overview

Fireproof putty, also known as firestop putty or moldable fire barrier, is designed to seal openings around cable trays where they pass through fire-rated walls, floors, or ceilings. It is pliable, easy to mold, and adheres to most surfaces, providing a reliable barrier against flames, heat, and smoke penetration. These putties are suitable for both new construction and retrofit applications.

Common Products and Types3

M Fire Barrier Moldable Putty+: A one-part, halogen-free putty that can firestop electrical outlet boxes, cable trays, conduits, and metal pipes. It is UL Listed and conforms to a wide range of fire-rated systems. The putty is pliable, adheres well, and can be reused for additional cables.

KBS® FR Caulking and Foamcoat HS: European-certified solutions for sealing cable penetrations, including complex cable systems and support constructions. These products are tested to DIN 4102-9 and EN 1366-3 standards, offering fire resistance up to EI120 for double-panel systems. Hilti Firestop Putties: Available as pads, sticks, and cable discs, these products are quick to install and suitable for small cable penetrations or outlet boxes, reducing the need for complex approvals.

Organic Firestop Sealants: Available from suppliers like Alibaba, these putties are marketed for cable tray fireproofing and can be customized for specific tray sizes and configurations.

Installation Guidelines

Measure the Opening: Ensure the opening around the cable tray is slightly larger than the tray dimensions to allow proper placement of putty or pillows. Apply Pliable Putty: Mold the putty around the cables or tray edges, filling all gaps to create a continuous fire barrier. For larger openings, combine putty with firestop pillows or mineral fiber boards.

Check Compliance: Use UL Listed or EN-certified products to meet local fire safety codes. For unusual tray sizes or configurations, consult the manufacturer for engineering judgment letters or technical guidance. Retrofit and Maintenance: Many putties are reusable, allowing for cable additions or replacements without compromising fire protection.

Key Considerations

Tray Type: Ladder, solid-bottom, or perforated trays may require different sealing approaches. Fire Rating: Ensure the putty system matches the required F-rating (flame) and T-rating (temperature) for the wall or floor penetration. Environmental Conditions: Some putties are suitable for high humidity or outdoor use, while others are intended for indoor applications only.

Compatibility: Verify that the putty adheres to the tray material (steel, aluminum, or fiberglass) and surrounding construction surfaces. Using fireproof putty effectively ensures that cable tray penetrations do not compromise the fire integrity of walls or floors, maintaining safety and compliance in industrial, commercial, and residential installations.