When NM cable is run on a surface facing the attic, what is required to protect it from physical damage?

When NM cable, commonly known as non-metallic sheathed cable, is run on surfaces facing an attic, it is essential to protect it from potential physical damage. The requirement for substantial guard strips is based on the consideration that attics can have various materials, tools, or other objects that may inadvertently cause damage to the cable. Guard strips provide a physical barrier that helps prevent any impact or contact that could compromise the integrity of the cable insulation.

In contrast, insulating covers, while useful for thermal protection or additional insulation, do not specifically address the risk of physical damage in the same way guard strips do. Metal sheathing offers a different method of protection but is not typically necessary for NM cable installations within an attic, where guard strips are deemed sufficient. Additionally, the notion that no protection is needed contradicts safety practices and electrical codes designed to prevent hazards associated with damaged wiring.