Trapezoidal cable trays passing through walls

Use a sleeve system or fabricated wall sleeve to safely pass a trapezoidal cable tray through a wall while maintaining fire and structural safety.

Installation Overview

When a trapezoidal cable tray needs to pass through a wall, it is important to maintain structural integrity, fire rating, and cable protection. Directly cutting a large hole in a fire-rated wall is not recommended, as it can compromise the barrier and create hazards during seismic events or fire incidents.

Sleeve Systems

A sleeve system is the preferred method for wall penetrations: Stop the cable tray a few feet short of the wall. Install a rigid sleeve through the wall that matches the wall's fire rating. Resume the tray on the other side of the wall, ensuring proper alignment.

The sleeve allows for expansion of intumescent firestop material and isolates the tray from the wall. This method reduces the size of the hole, simplifies firestopping, and allows for future cable additions without compromising safety.

Wall-

Mounted Supports

For wall-mounted installations: Use brackets, supports, or hangers to secure the tray to the wall. Fabricated wall sleeves, such as those from Legrand, provide rigid and aesthetically pleasing support for the tray at the wall penetration. Ensure the tray is level and properly aligned with vertical hangers or cross members to maintain cable bending radii and prevent stress on the cables.

Firestopping Considerations

Firestopping materials must match the wall's rating and accommodate seismic movement. Avoid rigidly routing the tray through the wall without a sleeve, as earthquakes or vibrations can dislodge firestop material. A series of smaller penetrations is easier to firestop than one large hole.

Weatherproofing and Structural Integrity

For exterior walls or areas exposed to moisture, consider vertical penetration weatherproofing systems using fibre-reinforced liquid membranes to prevent leaks and thermal breaks. Ensure the sleeve or penetration system can accommodate unusual shapes or multiple trays if needed.

Practical Tips

Maintain proper rung spacing (6–9 inches) to protect cables and allow bending at the wall. Ensure all hangers and cross members are sized to support the tray load and allow horizontal adjustment. Grounding wires can be routed through a small sleeve to isolate them from communication cables.

By combining sleeve systems, wall-mounted supports, and proper firestopping, a trapezoidal cable tray can safely pass through a wall while maintaining compliance with building codes, fire safety, and structural requirements.