NEC 300.4(E) requires that boxes and raceways installed under roof decking be which?

NEC 300.4(E) requires that boxes and raceways installed under roof decking be which?

• A. Weatherproof
• B. Made of composite material
• C. Protected from physical damage
• D. Watertight

Answer: (C)

When wiring methods are installed in spaces under a roof deck, they face a higher risk of physical damage from items stored above, foot traffic, ladders, or other overhead activity. The requirement is to protect those boxes and raceways from physical damage to keep the conductors and terminations safe and intact. This mechanical protection helps prevent punctures, crushing, or movement that could compromise insulation or connections. Weatherproofing or watertightness isn’t the focus in this scenario unless moisture exposure is present elsewhere; the code specifically calls for protection from physical damage in this location. Composite materials aren’t required by this rule, as boxes and raceways may be metal or plastic depending on the installation.

When wiring methods are installed in spaces under a roof deck, they face a higher risk of physical damage from items stored above, foot traffic, ladders, or other overhead activity. The requirement is to protect those boxes and raceways from physical damage to keep the conductors and terminations safe and intact. This mechanical protection helps prevent punctures, crushing, or movement that could compromise insulation or connections.

Weatherproofing or watertightness isn’t the focus in this scenario unless moisture exposure is present elsewhere; the code specifically calls for protection from physical damage in this location. Composite materials aren’t required by this rule, as boxes and raceways may be metal or plastic depending on the installation.