Exposed cable trays in stairwells

Running cable trays through stairwells is generally not permissible under building codes, even if NEC compliance is maintained.

Electrical Code Considerations

From an electrical standpoint, NEC Article 392 governs cable tray installations. Cable trays are designed to support electrical cables, including power, signal, and communication lines, and can be installed in vertical or horizontal positions as long as they are properly supported and the cables are secured.

NE

C does not explicitly prohibit cable trays in stairwells, and technically, conduits or trays can run through vertical shafts or corridors if they meet NEC requirements for cable type, support, and spacing.

Building Code and Egress Restrictions

Despite NE

C compliance, building codes impose stricter limitations. Stairwells are considered means of egress, and most building codes, including BOCA 1014. 11.

2, prohibit installations that do not serve the stairwell itself. Only electrical equipment that directly serves the stairway—such as lighting, flow switches, or pressurization fans—is allowed in these areas. Running cable trays through stairwells for general building distribution is considered a violation because it can obstruct egress, compromise fire ratings, and create safety hazards.

Practical Implications

Cable trays can be installed in vertical positions and maintain integrity over decades if properly supported and fastened. Stairwell landings may allow certain equipment if it serves the stairwell, but running general-purpose cable trays through the stairwell is not permitted. Fire safety: Penetrations through fire-rated walls or stair enclosures must be properly fire-stopped to prevent the spread of smoke or flames.

Conclusion

While NE

C allows cable trays in many locations, building codes take precedence in stairwells. Therefore, it is not permissible to run cable trays through stairwells unless the cables serve the stairwell itself. For installations in other areas, ensure compliance with NEC Article 392, proper support, and fire safety measures.