In the 2023 NEC®, new exception 2 in Section 300. 4 (E) allows raceways, cables, and boxes to be installed without any spacing restrictions where metal-corrugated sheet roof decking is covered with a at least 2 inches of concrete slab, measured from the top of the corrugated. In the 2023 NEC®, new exception 2 in Section 300. A similar. Installing conduit on roofs requires careful attention to weatherproofing, load considerations, and code compliance to protect people and property. This guide explains the key code requirements, material choices, installation practices, and inspection steps to keep rooftop conduit installations. The National Electrical Code (NEC) governs electrical junction box rules.
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