All tray items whether stored outside or indoors, should be placed on sufficient dunnage to enable future mechanical lifting. All material finishes are prone to storage stain if they are. But before you lay the first tray or clamp down a single cable, you need a solid plan. This guide breaks down the process step by step. Mark the cable tray route based on your electrical cable tray design and site. en completely installed, without damage either to conductors or structural system use maintain spacing or to keep cables in place when the tray is ect the minimum bend ra-dius for cables as they exit the bottom of the cable tray. Structural building members should never be cut, and cable trays should not be installed in hoist ways or where subject to.