Metal Conduit – The equipment you’ll need for a successful install

For the vast majority of readers everything in Jason’s electrical section is 100% accurate and meets National Electric Code (NEC). There are exceptions though.

chicagoland

Many of my Chicagoland brethren and I, fall into that minority… lucky us.

Type NM wire (commonly referred to as Romex) is NOT up to code in Chicagoland.

Yes, that’s right, your local city ordinances have the power to override the NEC and enforce their own local code. Seems silly, but I’m sure they have their reasons – 1871 Great Chicago Fire? Who knows…

So Adam, if I can’t use Romex, the wiring method widely used by 90%+ of American homes, what do I need to use? 

Picking up the sarcasm? Good, I’m laying it on pretty thick… 

The Answer: Metal Conduit!! 

Now, I’m clearly being facetious about this, but metal conduit does have a lot of advantages over romex despite it being somewhat more difficult to install. One of the main ones, is that conduit is much more future proof.

Even with drywall up, you can run fish line to add wiring whereas with romex stapled to studs, once the drywall is up, you cannot modify or rerun wiring without tearing down the drywall. Once you get the hang of it, and learn some basic routing techniques, its not THAT much harder than running romex.

Having said that, now that I have completed my conduit installation, I would say this is a job best left to the professionals.

neo-matrixI say that not because I believe the work the be overly technically difficult, but it is time consuming for a novice, and the pros know ALL the angle bending tips, and can visualize the best conduit routing techniques.

They see the way its going to play out before it even happens – kind of like Neo from The Matrix.  Am I the only one who didn’t realize Neo was an anagram for One? As in “The One”? See that movie is deeper than you thought… or not… 

If you are a stubborn mule hell-bent on saving every penny possible by DIYing your way through this basement finishing project or feel your budget tightening because you have a wife that decides she wants to remodel the downstairs bathroom right in the middle of your basement project (love you dear!). I’m here to help!

This will be article 1 of 2 on metal conduit. Article 1 will be on the materials needed (compared to a romex install). Article 2 will focus on the install itself. 

The Equipment:

Metal Conduit:

Duh! This actually can be overwhelming when walking into the ole HD or Lowe’s. There are several types of conduit:

RMC –  Rigid Metal Conduit - This is quite thick, and usually has threaded ends and uses threaded connections. Super heavy duty and used mainly in commercial/industrial applications. Not typically used in residential wiring. I’d be surprised if this was code for your home.

GRC/IMC –  Galvanized Rigid Conduit/Intermediate Metal Conduit - These come between RMC, and the next type, EMT, as far as weight, cross section size, and cost. Also not terribly common in residential applications. 

Metal ConduitEMT – Emergency Medial Techni… oops wrong acronym… Electrical Metallic Tubing: It is one of the most common types of conduit for residential applications which require it. They are typically a coated steel or aluminum and most commonly come in 1/2” diameter.

They are not threaded so they rely on a variety of set screw connectors to tie together. I’ll get to those in a minute.

Conduit comes in 10 foot lengths and runs in the $1.50-$2.00 range per piece. Plan on needing 25+ pieces to run an average sized basement. 

Other - There are other types of conduit including PVC and flexible metal conduits (commonly known as BX). These may or may not be allowed by local code. Be sure to always check before using these types.

A Conduit Bender

metal conduit bender toolHelpful to have a buddy who can lend you one, thanks John! If not, they are not terribly expensive. You can purchase one here on Amazon.

I’d say making accurate bends with the bender is more of an art than a science. You know how they say it takes time to master something? Well it takes time to just become barely adequate with a bender.

Plan on wasting several pieces of conduit screwing up bends. This is where the pros have a major, major advantage given their experience.

Watch youtube videos, and read up on the interwebs to learn how these work. You could devote an entire website to this tool… oh wait someone has. Check it out here.

A Conduit Cutter

metal conduit cutterI highly recommend buying/borrowing one of these. Check them out here.

While this could be done with a standard hacksaw, the cutter saves you at least a minute or two per cut.

Multiply this by the hundred or so cuts you are going to make and this little tool could save you hours just in cutting.

Most tools come with a built in reamer. You want to make sure to clear any sharp edges left from cutting to avoid wire sheathing from cutting and creating shorts. 

Metal Boxes

Metal Conduit boxesJason’s electrical page talks about the plastic blue boxes. These are designed to work with romex. They will not work with metal conduit.

The metal boxes are basically the same, but have metal punch out tabs to mate with the connectors that attach metal conduit.

 

Connectors

Metal Conduit AdaptersThere are 2 main types: connectors that join 2 pieces of conduit, and connectors that join conduit to a box.

Both are easy to use and simply require a screwdriver to install. Buy a contractors box of each – you’ll plow through these.

 

Pre-formed 90 degree bends

Metal Conduit preformed 90sThese are in the optional but recommended for novices category.

I’m sure pros wouldn’t be caught dead buying these since 90 degree bends are by far the easiest bends to make. But with as many 90s as you are going to make, for a novice, having these was helpful to layout to runs. 

Offset box connectors

Again, optional but recommended for novices. An offset bend is another “simple” bend for a pro.

My goal here was to minimize the number of bends I had to make, and speed this process up. Since you need an offset at virtually every box, these little guys save you the time. Plug them into the box, connect a straight piece of pipe spanning the length of the stud, and away you go. 

Conduit “Staples”

Metal Conduit clipsThese are similar to the romex staples, only metal and bigger. They come in several types and are used to hold the conduit to joists/studs over long runs and near boxes. 

Those are the basics. You’ll still need many of the other standard electrical tools like wire, wire connectors, strippers, voltage tester, etc.

Also, the same switches and outlets apply as with romex.

Jason’s electrical pages cover these in more detail. This was to simply cover the supplies unique to conduit. Check back for Article 2 of 2 where I will share some tips and tricks on how to plan runs, and how it differs from running romex.

Adam_Profile

Are you from Chicagoland and have shared my pain pleasure of running conduit?

Are you from a different region of the country which also requires metal conduit? Let me know in the comments below! 

- Adam 

Sweet, sweet candy.  Part II, Installing Metal Conduit, is now available (for free)!

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  1. Adam – Fantastic article on metal conduit, but what a pain. Still, bending metal is super manly.

    REMINDER: Metal conduit is only required in limited areas across the US and Canada. If standard Romex wiring is allowed by code – which it is more than 90% of the time – you should use that.

    If you live in an area that you know REQUIRES metal conduit for basement wiring, please add a comment here so everyone else from area is in the know.

    Thanks ! – Jason

  2. David Perea says:

    I live in the Chicago area and just finished this part of my basement as well…the whole thing, start to finish. Conduit bending, of all the things I’ve done up till this point, has certainly been the most challenging to master. You are 100% correct in noting that people that do this everyday can visualize their runs. I was able to do this with some confidence probably toward the end of my install. The hardest part of that visualization is adhering to the 4 turn rule, which limits the total degree of bends you’re allowed to 360 degrees between pull points. This is harder than it sounds when you have obstructions you need to go around.

    But bending is pretty easy to do once you get the hang of it. If you master the offset bend, the straight 90 and the 90 “kick”, those are pretty much the only 3 bends you’ll really need in an average basement.

    I also found the codes for box fill for wires quite challenging and I took the advice of an electrician friend of mine that said I should install 4″ square boxes for all my outlets and switches just to be safe. I would even take it a step further and say that for all of your switch boxes you should use 4″x2 1/8″ boxes for any box that you plan on running multiple circuits through. I ended up having to replace 3 out of the 6 switch boxes in my situation with the deeper box to fit all the wires and stay within code.

    Overall, if you understand the basic bends, understand the box and conduit fill requirements, your install should go pretty smoothly. When done right, it is one of the most rewarding jobs of your basement finish.

    • A lot of good points here David that were not touched on in the article. I agree that now that I am done, it was quite rewarding, just a lot of work, that’s all. Good luck with the rest of your finishing!

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