I own an old house (50s) for which the electrical is outdated (no ground, etc), so I am in the process of rewiring the whole house. The attic has tons of insulation (loose insulation atop fiberglass batts, etc), and below the insulation often it has plywood boards (subfloor). Navigating and finding anything through all this insulation is a real pain and time consuming.
Since much of the wire will be routed onto the top of the plywood (and not beside the joists at 1 1/4" from their edges) once I run the wires parallel to the joists (joists are below plywood subfloor) I would imagine that the wire would need to be protected by a conduit or wood strips; so can one use emt conduit instead of wood strips on top of the attic subfloor and could the conduit be attached to the attic subfloor wherein the wires would run (and in case someone would go the attic he/she could step on the conduits)? It would be romex (sometimes thhn) inside the conduit (and the conduit would be derated to accommodate the nm-b wiring).
By the way, the attic is accessible; and the conduit seems a much better option due to make it easier to upgrade and change the wires in the future.