Cable tray installation does not automatically include continuous flat steel; it depends on the tray type, such as solid-bottom trays, which may provide continuous steel surfaces for EMI shielding and support.

Tray Material and Design

Cable trays are typically made from steel, stainless steel, aluminum, or FRP, with steel being common for heavy-duty applications due to its strength and durability . The design of the tray—ventilated, solid-bottom, or wire mesh—determines whether a continuous flat steel surface is present. Solid-bottom trays provide a continuous steel base, which can act as shielding against electromagnetic interference (EMI) and support sensitive cables . Ventilated or ladder-type trays, by contrast, have rungs or perforations and do not include continuous flat steel.

Structural Considerations

Some cable tray systems, like Eaton's KwikSplice channel, use a continuous “dove-tail” splice design to enhance structural strength and reduce deflection, but this is not the same as a continuous flat steel surface across the tray bottom . Continuous flat steel is generally included only when the tray design specifically calls for a solid base, such as for EMI protection or when supporting small instrumentation cables that require full coverage .

Installation Implications

During installation, the tray system must be fully assembled before pulling conductors to maintain structural integrity and prevent cable damage . If continuous flat steel is required for a project, the installer should select solid-bottom steel trays rather than ventilated or ladder-style trays. Accessories like covers, barrier strips, or mounting plates may also be used to achieve continuous coverage where needed .

Summary

• Continuous flat steel is not inherent in all cable tray installations.
• Solid-bottom steel trays provide continuous flat steel surfaces for EMI shielding and cable support.
• Ventilated or ladder trays do not include continuous flat steel.
• Selection depends on application requirements, including load, EMI protection, and cable type. For projects requiring continuous flat steel, ensure the specification calls for solid-bottom steel trays and verify the material and finish according to environmental and mechanical requirements .