How to Cover Exposed Romex
Around 90 percent of homes within the United States are wired electrically using ROMEX, the trade name for non-metallic (NM), sheathed cable. This type of wiring system is simple to run and very convenient. However, it’s essential that you do not have any exposed ROMEX in your home and the wiring should be completely covered.
The foundation for all local building codes, The National Electrical Code, requires very specific guidelines for the installation of electrical wires so that they are protected from any damage. While there are proper uses of ROMEX that will typically avoid any exposed wires, if you’re experiencing this in your home, you essentially have two options.
In order to conceal your nonmetallic sheathed cable, you can either use a conduit such as PVC, ENT or EMT or a product called WireMold to hide the wires safely. We’ll explore, in detail, your choices when it comes to hiding your exposed ROMEX, as well as some types and particular uses for this type of cabling.
What exactly is ROMEX?
If your home was constructed (or rewired) after 1965, it was likely installed with a wiring system containing NM, or non-metallic sheathed cabling. ROMEX, as it is more typically known, is the most common brand name for this type of NM wiring.
ROMEX is an electrical cable that houses two or more insulated conductors and a bare copper ground wire within an outer plastic sheathing. The non-metallic cable dates all the way back to 1922 when it was invented by the Romex Company. It was first recognized by the NEC (National Electrical Code) in 1926 and came into more widespread use in the early 1960s.
Previously, woven rayon was used as an outer sheathing before Romex and plastic sheathing became the industry standard. NM cable is most notably used for running residential electric wiring in concealed locations such as within walls, ceilings and floor cavities. Although general conduit is the standard for more exposed locations, there are cases where NM wiring is exposed and needs to be hidden.
Understanding the Difference Between Two-Wire and Three-Wire Non-Metallic Cables
The most commonly installed Romex cables are considered “two-wire” or “three-wire” cables. This description signifies the number of insulated wire conductors within the outer sheathing. However, both types of cables contain an additional bare-copper ground wire; so, the designation is slightly misleading.
However, the “two-wire with ground” cable contains one insulated conductor that has black insulation and the other white insulation. White is typically neutral whereas, the black is normally the hot wire. In contrast, the “three-wire with ground” cabling consists of a white neutral wire, an additional black and a red hot wire.
In order to prevent the wires from sticking together within the sheathing, both types have a paper wrapping intertwined throughout the inside. The paper wrapping, bare copper wire and all insulated conductors are kept within a durable PVC plastic casing. The outer cover allows the NM cable to be heat resistant and non-conductive.
Types of Non-Metallic Cables and Their Uses
In order to better understand Romex, or non-metallic cables, you need to be aware of the various different forms. Each of these types will depend on the intended use and location of the wiring.
Building Cable (NM-B)
This type of NM cable is the typical option used for residential wiring inside flooring, walls and ceiling openings. The NM-B cable is permitted to be used in dry locations and should never be installed outdoors or buried under ground.
In the past, all non-metallic cables had white sheathing, however, the NM-B cables on the market are color coded for consumer convenience. Here are the various forms:
- White Sheathing: This cable has 14-gauge wires and is used for 15-amp circuits.
- Yellow Sheathing: This type contains 12-gauge wires and is used with 20-amp circuits.
- Orange Sheathing: Orange will have 10-gauge wires and be used in tandem with 20-amp circuits.
Underground Feeder Cable (UF-B)
If the cabling needs to be installed below ground, a very specific type of cable is required. The UF-B cable, or underground feeder cable, has wire conductors embedded in solid plastic instead of a hollow outer sheathing.
This type will be utilized when running circuits beneath ground to a shed or garage or when power needs to be supplied to a landscaping feature. UF-B cables will typically be gray.
Service Entrance Cable (SE, USE)
The last type of NM cable on our list is utilized by your utility provider to deliver overhead or underground electrical service to your property. SE refers to the type that is installed aboveground and USE is used for service wires ran underground. As a homeowner, you will likely never deal with this type and should always be handled by utility professionals.
Options for Covering your Exposed ROMEX
Although, in most cases, your non-metallic cabling will be concealed and protected in your walls, flooring or underground you can experience a case of some exposed wires. According to the National Electric Code, “Cable shall be protected from physical damage where necessary by rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, Type RTRC marked with the suffix -XW, or other approved means.”
When you break it down, you essentially have two options for hiding your exposed ROMEX. You can either choose to place it within a PVC, ENT or EMT conduit or use WireMold. Let’s dive into the various options.
Plastic Conduits to Cover Exposed ROMEX
The two options for plastic conduits are rigid PVC pipe and ENT, or electrical non-metallic tubing. Rigid PVC is very versatile and can be installed inside walls, outside and underground. It’s also a very budget-friendly material.
ENT is a corrugated, flexible plastic tubing that is most often used for dry interior projects or in particular places inside a building where moisture is present. However, ENT itself can be susceptible to damage and may not be the best option for covering your ROMEX depending on your situation.
EMT to Hide Exposed ROMEX
EMT is a type of metal conduit with relatively thin walls. It’s typically constructed of galvanized steel but can be found in aluminum. This sort of conduit is relatively inexpensive and is an excellent choice for protecting your wires from physical damage.
EMT can be easily cut, bent and installed depending on your particular needs. With the proper supports, fittings, fasteners and non-corrosive materials, it can be installed outdoors. However, it’s more typically seen used within residential homes to conceal wiring.
Using WireMold to Conceal Exposed ROMEX
The final option for covering your non-metallic wires is the use of a WireMold raceway. WireMold is the trusted provider of cable management products and the leader in their industry. Their products are a simple, non-obstructive way to conceal cables and wires.
However, make sure that you’re buying the WireMold product with the proper dimensions to fit your wiring. In some cases, the WireMold elbows may be too tight a bend to fit ROMEX and you may want to choose one of the other concealment methods.
Wrapping it Up
Romex, or non-metallic (NM) sheathed cabling are very commonly used in most homes throughout the U.S. Although you’ll typically already find them concealed within your walls, floors or underground, there are some cases where the wires are left out in the open.
It is very easy for non-metallic sheathed cable to become damaged when left exposed. Romex is especially vulnerable when installed under or over ceiling or wall framing. This fact is exactly why the National Electrical Code requires that cables be covered and protected in these areas.
Regardless of the case, you should utilize plastic conduits such as rigid PVC or ENT, a metal conduit like EMT, or a WireMold raceway to conceal and protect your wires. However, when it comes to any sort of electrical work, installation can be very dangerous and you should always consult a professional.
Consult “ The Pros and Cons of Whole House Surge Protectors [Explained]” for more home electric tips and tricks.
Jessica considers herself a home improvement and design enthusiast. She grew up surrounded by constant home improvement projects and owes most of what she knows to helping her dad renovate her childhood home. Being a Los Angeles resident, Jessica spends a lot of her time looking for her next DIY project and sharing her love for home design.
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