Why Is Romex Illegal?

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Are you in the process of a wiring project, but not sure what type of wire to use? Have you heard that Romex is illegal? If so, you’ve come to the right place! In this blog post, we’ll explain why Romex is illegal and what type of wire should be used instead.

In this blog, we’ll explore the legality of Romex wiring, what it is, and where it’s allowed and not allowed. 

Romex is a brand name for nonmetallic sheathed electrical cable. 

It has been in use since the early 1950s and was first introduced by National Electric Code (NEC) in 1968. 

The name “Romex” comes from the two main components of the cable: rubber insulation and metallic sheathing. 

Over the years, Romex has become the most common type of wiring used in residential and commercial construction. 

There are certain restrictions on where it can be used due to safety and fire codes. 

We’ll look at these in detail so you can better understand when Romex is allowed and when it isn’t.

Is Romex Illegal to Use?

Romex is a type of electrical wire commonly used in residential and commercial buildings. 

Despite its popularity, the National Electrical Code (NEC) does not allow Romex to be used in certain situations. 

Romex is not allowed outdoors because it is not water-resistant and can become damaged if exposed to moisture. 

Additionally, Romex cannot be used in residential homes that are more than three stories tall. 

Romex is also not allowed to be run exposed or in conduit due to safety concerns. 

However, Romex can be used in NYC, as well as commercial buildings and garages under some restrictions. 

When installing Romex, it must be supported at regular intervals to ensure the wires do not become damaged or create a fire hazard.

Where Is Romex Not Allowed?

Why Is Romex Illegal
Why Is Romex Illegal

Romex is not allowed in residential homes that are more than three stories high. 

This is according to the National Electrical Code and the NEC, which state that Romex conductors cannot be used in residences higher than 3 stories, making it illegal to use them in this context. 

Furthermore, Romex is not allowed to be attached across the surface of framing members as it poses a significant fire hazard. 

This means that any wiring done in these situations must be done with other wiring methods such as conduit or armored cable. 

Additionally, Romex should not be run through holes bored into exposed framing members as this can also create a fire hazard.

Where Is Romex Allowed?

Why Is Romex Illegal
Why Is Romex Illegal

Romex is a popular type of electrical wire used in residential and commercial applications. 

It is allowed for branch circuit wiring in homes and commercial buildings that are no more than three stories high, according to the National Electrical Code. 

Romex can also be used in garages and other exposed locations, but it must be securely fastened to framing members or other supports. 

In addition, Romex is allowed to be run through holes bored in framing members, but it cannot be attached across them. 

When running Romex through conduit, however, it must be installed in a manner that prevents damage to the insulation. 

With proper installation and adherence to safety regulations, Romex can be a great option for wiring projects.

Is Romex Legal In NYC?

In New York City, Romex is not allowed in buildings that exceed three stories. 

However, it is legal to use in residential applications that do not exceed three stories. 

It must be protected from risk of damage, water, and sunlight. 

In the event of wanting to tear down an apartment building, Romex may be used. 

Additionally, it cannot be run exposed or in conduit. In Chicago and other cities, Romex may be subject to different laws and regulations. 

It is important to always check local codes when using Romex for wiring purposes.

Is Romex Allowed In Commercial Buildings?

Romex is allowed in commercial buildings up to the third floor. 

It does not matter if the structure is residential or commercial, as long as it is a type III, IV, or V building. 

However, 334.12(A)(1) of the 2002 NEC does not allow romex as open runs above drop ceilings in other than one & two family and multifamily dwellings. 

Though some localities may prohibit it, California allows it. 

Therefore, Romex can be used in commercial buildings within the regulations set by local authorities.

Can Romex Be Exposed In Garage?

No, Romex should never be exposed in a garage. 

For safety reasons, all Romex wiring should be properly covered by conduit or raceways. 

This is especially important in areas where there is potential for physical damage from outside sources, such as a garage. 

If you’re running Romex through studs or joists, it must be protected by a sleeve or conduit. 

In addition, Romex must not be attached across exposed framing members. 

If you are running it through holes bored in the centers of exposed framing members, then it must be covered with an approved material. 

By following these guidelines and using the appropriate materials, you can ensure that your Romex wiring remains safe and secure.

Can Romex Be Run Exposed?

Why Is Romex Illegal
Why Is Romex Illegal

No, Romex wiring should not be run exposed. 

Code and common sense both dictate that Romex must run through conduits if it is to be used in residential houses. 

The National Electrical Code 2011 requires that NM cable be in conduit when protection from physical damage is required. 

It is also not allowed to be attached across the framing members of exposed wall studs either. 

It is important to note that while it is allowable for NM cable to run through holes bored in the centers of exposed framing members, it should never be left exposed in a residential house where the wiring may be subject to physical damage or accidental contact.

Why Can’t You Run Romex In Conduit?

The NEC calls for all non-metallic wires to be used in conduits to protect them from physical damage and reduce the risk of shock. 

Romex is a non-metallic wire, but it is somewhat stiff and difficult to run through a conduit. 

If Romex is not installed correctly, it can cause a safety hazard due to the exposed wire becoming tangled or pinched. 

Additionally, Romex does not offer the same level of protection that metal conduit does, which is why the NEC requires metal conduit for certain applications. 

For these reasons, running Romex in a conduit is generally not allowed and can be dangerous.

Why Is Romex Illegal In Chicago?

In Chicago, Romex is illegal due to the city’s strict electrical code standards. 

Cook County, which includes Chicago, requires all electric wiring to be done with EMT (electrical metallic tubing). or rigid metal conduit.

The authority having jurisdiction shall approve electrical equipment for installation and use. Electrical Conductor Insulation and Identification: Conductors shall be of copper or aluminum. Bare copper conductors

The surrounding counties may be able to use Romex, but Chicago and most of the suburbs around it do not permit its use. 

Romex wiring is safe and approved by the National Electrical Code when installed correctly, but it is not allowed in the city of Chicago.

Can You Run Romex Under A House?

Romex should not be run directly underground, as it is not designed to be used in this manner.

However, it can be run through holes bored in the framing members of a house and left exposed. 

The Romex must also have proper support, such as straps or cable clamps. At least every 4-1/2 feet, and within 12 inches of any outlet box or junction box. 

When running Romex outside or under a house, be sure to check with local building codes for additional safety requirements.

What Is The Rule For Supports On Romex?

When it comes to supporting Romex, the National Electrical Code (NEC) is very specific. 

Romex must be supported and secured by staples, cable ties, straps, hangers, or similar approved devices.

If run through holes bored in the centers of exposed framing members. It must not be attached across the face of the member. 

Furthermore, when running Romex in wet or damp locations such as basements and garages. It must be installed within conduit to protect it from moisture. 

Additionally, Romex is not allowed in residences higher than 3 stories. And not allowed to be exposed to sunlight or other potential sources of damage. 

With proper installation and maintenance, Romex can be a safe and reliable way to power your home.


In conclusion, Romex is a type of electrical wiring that is widely used in residential and commercial buildings. 

It is not allowed in certain areas, such as outdoors, where it could be damaged or exposed to water and sunlight. 

Furthermore, it is not suitable for use in conduit and cannot be run exposed in garages. 

Additionally, Romex may be illegal in some cities or states due to local regulations. 

When installing Romex, it is important to follow the manufacturer’s guidelines and the local building codes to ensure safe installation.

Best Wishes!


Q: When is Romex not allowed?

A: Romex may not be allowed in certain situations, such as in exposed locations, where it needs to be protected by conduit, or where local building codes require the use of metallic conduit.

Q: Can Romex be used in new construction?

A: Yes, Romex can be used in new construction if it complies with local building codes and is installed properly by a qualified electrician.

Q: What is the purpose of using conduit?

A: Conduit is used to protect and provide a pathway for electrical wires. It helps prevent damage to the wires and adds an extra layer of safety.

Q: Can Romex be used outside?

A: Generally, Romex should not be used outside unless it is specifically designed for outdoor use and is installed in a manner that provides adequate protection from moisture and other elements.

Q: Can Romex be used in the Chicago area?

A: Yes, Romex can be used in the Chicago area as long as it complies with the local electrical codes and regulations.

Q: Is Romex safe?

A: When installed properly and used according to code requirements, Romex is considered safe for use in residential wiring.

Q: Is it necessary to hire an electrician for Romex installation?

A: It is highly recommended to hire a qualified electrician for Romex installation to ensure proper wiring, adherence to local regulations, and overall safety.

Q: Can Romex be used in a remodel?

A: Romex can be used in remodel projects, but it is important to consult with a licensed electrician to determine if any specific requirements or modifications need to be made.

Q: Can Romex be used in a PVC conduit?

A: No, Romex cannot be used inside PVC conduit. It is designed to be used as a standalone NM cable and should not be pulled through conduit due to potential damage to the cable’s insulation.

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About Charlie D Paige

Charlie is a massive DIY fan, with dozens of DIY projects under his belt - ranging from tiling to electrics, and concrete pads to walls. Charlie loves tinkering, seeing how things works, the outdoors and playing with power tools... so is it any wonder that he's completed so many DIY jobs over the years?

Charlie loves spreading his hard-won DIY experience with the world via this blog.