This guide walks you through the tools, techniques, and best practices for running cable through exterior walls safely and professionally. For professional help with low voltage wiring installation, call Cabling Solutions Group at (520) 605-1405. NEMA VE2 was developed by the NEMA Cable Tray Section, of which MP Husky is a charter member. Proper planning for installing cable tray includes calculations based on loading, support. Different wall types require different approaches and tools. A common wall construction involves several layers: Exterior Sheathing: Often made of plywood or oriented strand board (OSB), this layer provides structural support and a base for siding. This procedure must be executed with precision to ensure the continued integrity of the building envelope.