Do walls and ceiling need to have drywall installed for electrical? Partially finished basement

Question

Background

I recently finished most of the basement, making a bedroom and bathroom in the process. This leaves a section of the basement unfinished which consists of a laundry room and storage area. The laundry room has the utilities like furnace and hot water heater. The storage area has big wooden shelves and a mini work shop.

Question

So now in the unfinished section, one of the framed walls doesn't have drywall on the one side and the ceiling joists also don't have drywall or anything covering them. All wires are ran through the middle of the joists / studs per NEC requirements. The big question that I haven't found an answer to, do I need to drywall either the ceiling joists or wall?

Answer 1

You don't need drywall, but the cables that are considered "exposed to damage" need to be protected. Drywall is one way to do that. The overhead wires are usually not considered to be exposed to damage, but that can become a grey area if the ceiling height is low and they are thus less than 8 feet from the floor (where that can be considered "exposed to damage" per code language.)

Having already installed the cables, it's a bit late for "protective sleeves" of conduit, without a lot of re-work. A board over the studs covering the cable path(s) may be considered adequate. For electrical installations that you expect to be left exposed on the surface, conduit and metal boxes with "exposed work covers" are a typical way to provide protection.

Drywall, cementboard, and plywood are all typical ways to get there. Plywood (other than the current-time pricing craziness) is a good wall covering for a shop in most cases, as you can screw things to the wall anywhere for tool storage purposes. Cementboard (tile backer) is good for wet locations, even if you don't tile over it.

Answer 2

The Code says:

NEC 334.15 Exposed work. In exposed work, except as provided in 300.11(B), cable shall be installed as specified in 334.15(A) through (C).
(B) Protection from Physical Damage. Cable shall be protected from physical damage where necessary by rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, or other approved means. Where passing through a floor, the cable shall be enclosed in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, or other approved means extending at least 150 mm (6 in.) above the floor.

The problem is "where necessary" is ambiguous. It doesn't say all exposed NM is subject to damage, it doesn't say below 5', 7', or 8'. Many jurisdictions recognize this and pass local ordinances that further define it, you really need to check with your local inspector to know for sure.