EMT or Plastic Conduit?

[Dan Clark]

Hi. I'm adding there circuits to my garage to add electric heat and for power tools - two 220V 30 Amp circuits and one 110V 20 Amp circuit. For layout flexibility, conduit is my choice. But I'm not which sure which is better - EMT or plastic.

Which do you prefer? Any benefits of one versus the other? is one any easier to install than the other?

Thanks for your advice!

Regards,

Dan.

P.s. while saving a buck is always nice, I don't mind spending a bit more to get the best alternative.

 

[Provincial]

If your conduit runs will be exposed the EMT will look cleaner, and will not need a ground wire run in the 20A circuit. You will need to buy or rent a conduit bender to make it look right. You will need a hacksaw or abrasive chop saw to cut it and a reamer to remove the burrs from the cuts. The cost of the tools should not be enough to deter you from using EMT, since you can do your job with 1/2" or 3/4" material, and both are easy to work with and materials are commonly available. It is more resistant to damage than plastic, but not much. There are several threads about this on this forum.

PVC is pretty easy to run, you can buy ready-made 90* and 45* elbows, and only takes a wood saw to cut. If it is left exposed, the joints will show if you are at all sloppy with the glue. The cuts need to be chamfered on the inside to make feeding the wire easier and keep from abrading the jacket of the wire - I use a knife to peel off a bevel on the bore of the end. I cut PVC with a carpenter's miter saw, hacksaw, or hand saw. You can make minor bends by heating the PVC with a heat gun (I use a piece of 4" duct pipe to direct the heat all the way around the conduit, leaving the duct still split open to provide access for the heat gun snout the full length) but need to be careful not to reduce the ID when you do. You can buy coiled-spring devices to prevent collapsing the ID from electrical supply houses.

I have a steel-framed building with stick-frame interior walls and floors in one end. I used PVC condit where it was covered by drywall or buried in/below the concrete, Romex through the wood walls/floors, and EMT for the surface-mount runs in the workshop. Each has its place and works well.

 

[rabidsquirrel]

PVC will need to be supported more often, and no matter what it's going to sag eventually.

 

[sberry]

EMT, the choices of boxes, covers and fittings are huge. Plastic indoor seems to look amateur at best most of the time.

 

[porcupine73]

I used some sch. 40 PVC conduit in one of my garages, and, in retrospect, I really wish I'd of used EMT instead, mainly for the more professional, industrial look. If you are running multiple circuits in one conduit you may need to look at the deratings.

 

[FJ 432]

EMT, the choices of boxes, covers and fittings are huge. Plastic indoor seems to look amateur at best most of the time.

X2. It just doesn't look right.

 

[rlitman]

I use PVC underground, and outside when not in a place where it can be subjected to damage. EMT is far better when not subjected to weather, and since I cut it with a portaband, and have a bender, it's easier to work with for me than PVC.

 

[pattenp]

If your conduit runs will be exposed the EMT will look cleaner, and will not need a ground wire run in the 20A circuit.

Even though technically the EMT can provide the ground it is better to pull a ground wire. Every connection in the EMT is a potential point for the ground to become unbonded.

 

[Naq]

I think you've got consensus so I'm not going to dogpile. I've got a single unpainted PVC conduit to a pvc single gang box/switch in the basement bathroom from the PO and I feel disappointed every time I see it.

 

[Dan Clark]

Gentlemen (Ladies?),

Many thanks for the excellent feedback. I decided to go with EMT and pull a ground wire. I may have to rent or buy a 1/2" EMT bender, but since I've never installed EMT (much less bent some), going with premade bends and other fittings seemed like a good choice. That should help reduce the "screw-up factor".

Best regards,

Dan.

 

[slip knot]

If your gonna use EMT buy a bender and get some instruction on bending the tubing. You can make some really nice looking bends without much experience.

 

[browntown]

hmm, I didn't think plastic electrical conduit looked *THAT* bad. My current jacuzzi/future air compressor line looks ok. I will take a pic

 

[matt151617]

I like PVC simply because it's easy to work with, and it's cheap. It can also be painted, which is nice if you need to blend it in more and it's too hard to run wiring in the walls. I've used it in a mud room to protect the wiring, and to hide big bundles of speaker wire in the basement.

EMT definitely looks cleaner and more professional though. In the garage setting, I'd definitely use EMT if the garage is finished. Unfinished, I just run plain exposed NM cable.