Actually, I tried to delete my post because I realized the only thing I was accomplishing with the 10 gauge cable was to save about 36" of 12 gauge cable - 18 inches from the panel to my first receptacle times two. Not worth it.

I learned not to post before finishing my first cup of coffee of the day. Please disregard the above question.

But since I a here, I have a new question, would wiremold generally be approved in a garage when it houses individual 12 gauge THHN wires protected by a 20 amp breaker and gfci outlets? Would it also be approved if it housed romex?

My new plan is 12 gauge romex from the panel to the first box and then I would like to run individual 12 gauge THHN wire through wiremold to subsequent outlets. Again the reason for using the THHN wire is that I have it and would like to use it up.

Thanks

Wiremold (the trademarked stuff from LeGrange) is an approved metal raceway and hence as far as the NEC is concerned it is fine for garages. However, it is only listed for individual THHN/THWN conductors, not type NM (romex). Yes, the best way would be to put a box in to meet up the NM to the wiremold.

All 115A 15/20A receptacles in the garage will need to be GFCI protected (either at the first receptacle and then chaining the others to the load side of that one or with a GFCI breaker).

Actually, as far as NEC is concerned, exposed type NM is permitted in residential garages though some local authorities don't like it.

Ron, are you saying that Wiremold can't be used for physical protection of NM?

As for garages, someone correct me if I'm wrong, but AFAIK NM has always been allowed in residential garages, provided that the cable follows, and is properly secured to, framing timbers.

If you expect a lot of moisture in the garage, UF would be better. Actually the code calls for NMC, but that's kind of a phantom product, I've never actually seen it offered for sale, and UF is an acceptable substitute. UF is also good for barns (corrosive atmosphere).

Yes, it is not listed for that. You have to follow the manufacturer's rules.

As I said, NM is allowed (subject to the general installation rules) for RESIDENTIAL garages as far as the NEC is concerned. Some local jurisdictions do not allow it exposed in garages, so you'll have to check what the local rules are.

Most garages are dry locations, but if yours is damp, then by all means use NM-C or UF if exposed. Note that the regular (500/700 series) wiremold is not approved for wet locations either to my knowledge.

This is your basic north east attached 2 car garage - I wouldn't say that it will ever be damp. Humid maybe in the summer time. There will be snow run off on the floor in the winter time. But 3ft off the floor where the cable is will be dry. At least as dry as the original cable which is installed inside the sheetrock wall.I am going to call the bldg dept and ask if they have a problem with wire mold. Thanks

The wire cannot go on top of the studs (in between) without protection. Like for an enclosed wall, you'll need to drill holes and add metal plates (or you should).

Unless the code has changed since I last checked, where you have to run exposed NM across garage or barn studs or trusses, you can add running boards (usually 1x2 lumber) and attach the cable to the running boards.

For crossing wall studs, for better protection, the running boards should be set back from the forward edge of the studs. This lets you use holes in the studs (as Weedmeister suggests) where necessary. In practice, it may be easier to use extra cable, go up to the header and across, then down the other stud.

In the case of trusses, you can nail the running boards over them. You don't ever drill trusses.

The code says you have to follow the building surface or use running boards. There are a few exceptions but just throwing it over the ceiling joists isn't legitimate.

I'm having a hard time understanding what David is suggesting. If you're using running boards, one typically nails them to the face of the framing and doesn't use holes at all.

Are you allowed to "throw it over the ceiling joists" if it's EMT or other rigid conduit?

You've lost me on just what your asking. Conduit can't just be "thrown" over the the joists, but if it is secured it may run on top of it.

Sorry, Ron, I was just trying to copy your phraseology. I mean, can EMT be mounted perpendicular to and below joists, with mounting brackets attached to each joist?

Yes, below or above, it is allowed as long as it's supported as required. It doesn't necessarily have to be each joist. In most cases that's within 12" of the ends and every 4 1/2 feet along the run.

Thanks, Ron, that's what I thought. So, at least every 4th joist if they are on 16" centers.