Cable trays and busways at floor level or at slab penetrations shall have a waterstop no less than 50 mm in height. Sealing shall be tight and reliable, without visible cracks or. Cable tray systems help organize and support electrical cables efficiently, but improper installation or maintenance can increase the risk of electrical fires. Understanding proper cable tray fire safety practices is essential for protecting buildings, equipment, and occupants. This document outlines the key requirements for cable tray layout, installation, and fireproofing in industrial and commercial environments. They seem like separate things, but they need each other to keep buildings safe. Power, low voltage control, data, or telecommunications wiring distribution systems can be used with cable trays.