Can You Run Romex In Conduit? Should You? [Considerations And Tips]

Electrical wiring systems are a technical and complicated aspect of your home because the National Electrical Code (NEC) and your local codes regulate them. If you're wondering whether you can or you should run Romex cables in a conduit, you're in the right place! We did the research for you, and here's what we found.

Yes, you can run Romex cables in a conduit. The NEC approves of consumers running non-metallic wires through tubes for protection from hazardous elements. However, you have to consider these precautionary measures:

  1. Never use Romex outdoors or in wet or damp locations.
  2. Make sure to never exceed the conduit fill requirement. 

While the NEC does not explicitly tell you not to run a Romex cable in a conduit, does this mean you should? The answer depends on several factors that you should keep in mind to ensure that you're doing everything correctly. Keep reading to learn more about this topic.

hazard-electrical-wiring-exposed-wire-wall, Can You Run Romex In Conduit? Should You? [Considerations & Tips]

Running Romex In A Conduit

Romex is not a standard wiring type but a brand. It is a type of non-metallic (NM) sheathed cable. While the NEC does not mention Romex cables, if you read anything that says NM cables, you may take it to mean Romex cables. 

When you have to do a conduit wiring task, it is vital to refer to the NEC and other related electrical standards. Generally, the NEC wants consumers to run NM wires through tubes as a way to protect the cables from exposure to harmful elements.  

As shown in the video below, you will have to meet the following considerations for running Romex cables in a conduit:

1. Never Use Romex Outdoors Or In Wet Or Damp Locations


The NEC explicitly prohibits using Romex cables in an outdoor setting. So make sure that you do not run a stripped Romex cable outdoors, especially as Article 334.12. (b)(4) says you can't use Romex in damp locations, including an underground conduit.

 2. Make Sure To Never Exceed The Conduit Fill Requirement

Chapter 9 Table #1 of the NEC also warns that for a single conductor, ensure that you do not fill more than 53 percent of the space inside the conduit. But as long as you don't exceed the conduit fill, you can run a single Romex cable in a conduit. 

Remember that it is crucial to comply with the standards set by the NEC to ensure that you don't put your family and yourself in dangerous situations and to keep your home or building safe. 

Safety Tips


Just because you can run a Romex in conduit does not automatically mean you should. Before doing so, you must keep the following pointers in mind:

Always Remember: Safety First!

You must familiarize yourself with the NEC and other electrical standards, especially your local residential electrical code.

While most people think this is a tactic to avoid any lawsuits as a building- or home-owner, its primary purpose is to protect and keep your life and property safe.

Electrical and wiring systems are highly technical. Mishandling them can leave you susceptible to electrocution and other fatal injuries.

The NEC and other electrical standards are laid down to ensure your safety and protection. This is why you have to keep yourself well informed.

Get Acquainted With Electrical Terms

As discussed earlier, Romex is not a standard wiring type. It is the brand name of a type of non-metallic sheathed cable produced by Southwire Company, LLC of Carrollton, Georgia. 

Check out this Romex cable on Amazon.

Romex is just one of the many NM cable brands that are commonly available. So if you have read some parts of the NEC and have seen any mention of NM cables, it may be taken to mean Romex cables.

On the other hand, a conduit is commonly defined as a tube or trough used to protect wiring. This definition seems easy to understand for someone not well-versed in the electrical field.

For professionals, however, a conduit is a type of raceway for wires or cables, while a tube or tubing is another type of raceway. 

Check out this NM electrical conduit on Amazon.

Consult A Professional Electrician

There are some things about electrical and wiring systems that you can DIY and things that require professional assistance.

If you don't feel confident enough to take on a Romex or conduit wiring job or you want to make sure that you're doing everything safely, never hesitate to consult a professional electrician.

How To Run Romex In A Conduit

romex wires on a blue background

Wires, by their design, resist during this process because they might be too flexible or the raceway they're supposed to go through is too small. You will want to use a lubricant of some sort (gel or soap) to make the cable slick.

A lubricated cable will encounter less resistance as you pull it through the conduit, making the task easier.

What if—even though there is less resistance pushing the cable through—you find that it still bends and tangles inside the conduit? This situation makes it challenging to finish the task. 

Running Romex in a conduit necessitates that you run the cable through and pull it to the other side. There are several methods for doing this, but the most commonly used ones are covered below:

String Method

You won't need to use any tools for this. You just need to tie a string to a rod, push through and connect the lower end of the string to the cable. Then use the upper end to pull it outwards.

Conduit Mouse Method

You can opt for the conduit mouse or a conduit piston method, but instead of a rod, like in the string method, you only need a small tool like a foam cylinder. 

The diameter of a conduit piston is smaller than that of the conduit. If you encounter twists and turns inside the conduit, you can use this method, but the only disadvantage here is the length of the wire.

Longer wires are much more challenging to run in a conduit.

Check out this conduit piston on Amazon.

Fish Tape Method

Lastly, you can try the fish tape method. This is highly recommended for a flexible conduit with lots of curves and turns.

The fish tape looks like a long, flat metal wire coiling around a spool with a hook at one end, which is used to pull wires through. If you lack experience handling conduits, this process might take a long time.

Check out this fish tape on Amazon.

Do I Need To Follow NEC Guidelines For Running Romex in Conduit?


Yes, you need to follow the NEC guidelines for running Romex in conduit. While it is not federal law, it is a uniform code dedicated to ensuring the safe practice of handling electrical wiring systems.

In Closing


The NEC does not explicitly prohibit running a Romex cable in a conduit, but you still have to refer to the NEC and other electrical standards in your state.

You can run a Romex cable in a conduit as long as you comply with the critical considerations we have discussed above.

If you want to read more on topics related to electrical wiring systems, please check out the following posts:

How To Cut Metal Wires [Inc. Without Metal Cutters]

How Many GFCI Outlets On A Circuit? [15 And 20 Amps]

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