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Where Romex Can & Can’t Be Left Exposed In A Home: Full Guide

A man with gloves and goggles wiring down a wall with wire cutters.

When installing Romex in different parts of your home, it is essential to know whether you can leave the wiring exposed or not. So, are there any parts of your home where Romex can be left safely exposed, or is this a bad idea?

Romex electrical wire must not be left exposed anywhere in the home. Instead, Romex should be protected by conduit, insulation, or installed behind walls. Romex must be firmly secured with fasteners every 4.5 feet, with the last fastener being 12 inches or less from the electrical panel.

As with any electrical work, safety is paramount. It is vital to know the specifications and installation requirements for Romex wire and how to protect it from hazardous exposure. This guide provides the essential information you need to install Romex safely.

Why Protect Romex And Not Leave It Exposed?

Romex, sold on Amazon, is a brand name non-metallic sheathing wire widely used for indoor home electrical applications. This type of wiring is most commonly installed for outlet and lighting circuits and for connecting appliances like:

  • water heaters
  • refrigerators
  • clothes driers

Romex has a PVC plastic sheath that contains two or three insulated conductors (hot and neutral) and a bare copper wire (ground). 

The sheath provides a measure of fire and water protection to the conductors inside the wiring. Nevertheless, Romex is not for outdoor or heavy-duty applications where it might encounter:

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  • wet conditions
  • extreme temperatures
  • scratches and dents

Damaged Romex doesn’t conduct electricity effectively and poses fire and electrocution risks.

For this reason, do not leave Romex exposed in any part of the home. This rule applies whether the wiring is in a:

  • basement
  • ceiling
  • crawl space
  • attic

TIP: Finishing your basement? Read this article to learn how to finish a basement without drywall.

Instead, it is advisable to ensure Romex is adequately protected by installing it with insulation or conduit. Maximum protection for the wiring is ensured by installing Romex cable inside:

  • ceilings
  • walls
  • underneath flooring

If installed without conduit, Romex must be secured firmly to supporting structures like walls or beams. It is crucial that the fasteners are close enough to one another so that the wire remains taught and does not sag (called straggling). Fastening Romex securely near the breaker box is also critical for ensuring it is not dangling dangerously.

An attic with romex in conduits in between the framing and insulation.
Romex must be protected with conduits or insulation

Basic Sizes And Specifications For Romex

Romex is available in different gauges (diameter of the wire), with each size rated for a different amperage. These are the three predominant Romex gauge sizes and their amp ratings:

  • 10 gauge: 30 amps
  • 12 gauge: 20 amps
  • 14 gauge: 15 amps

Romex is classified with a two-digit system, for instance, 10-2 or 10-3. The first number is the gauge of the wire, and the second digit indicates how many conductors are in the wire (excluding the bare copper grounding wire).

The various kinds of Romex have related but unique applications. For example, 12-2 is probably the most prevalent type of Romex in home settings. 12-2 is typically used for outlet and lighting circuitry and for conducting electricity to refrigerators.

Romex 10-2 is primarily for electrical heating appliances like panel heaters found on Amazon. A typical application for Romex 10-3 variety is connecting clothes dryers.

The following table summarizes the specifications for the principal types of Romex.

Romex Wire TypeAmperage (A) RatingTypical Home Applications
10-230Apanel heaters, water heaters
10-330Aclothes dryers
12-220Arefrigerators, outlet circuits, lighting circuits
14-215Acircuits for lighting

National Electrical Code Requirements For Romex Installation

To safely and legally install Romex wiring, it is essential to follow the National Electrical Code (NEC). The NEC defines Romex as an underground feeder cable and regulates it accordingly.

NOTE: Specific NEC regulations may vary according to the local jurisdiction and the way county inspectors interpret those rules. Indeed, in some jurisdictions, Romex is not allowed for residential use

Consulting with local authorities is crucial before installing Romex in your home.

#1: Don’t Leave Romex Exposed

To comply with the NEC, Romex cannot be left exposed in any part of the home. The wiring must instead be installed out of harm’s way and protected if needed.

In some parts of the country, amendments to national regulations stipulate that Romex must be protected by walls or conduits when installed below a certain minimum height.

#2: Fasten The Wiring Properly

To prevent straggling Romex, NEC regulations require that it is held securely in position every 4.5 feet with:

  • nails
  • clamps
  • hooks

The regulations also require a minimum distance of 12 inches between the junction box and the first fastener or clamp holding the Romex in place.

According to the NEC regulations, the supporting fixtures must not hold the Romex too tightly, because it could compromise the integrity of the plastic sheath and expose or puncture the internal conductors.

In addition, NEC regulations require that the fasteners are in proper working condition and not damaged and degraded. For example, rusting hooks or nails are not legally-compliant because they lose their ability to support Romex securely and might corrode the wiring over time.

#3: Permanent Not Temporary Use

NEC regulations stipulate that Romex is only for permanent wiring. Using Romex for temporary applications such as extension cords or wiring appliances contravenes the code.

#4: Buildings Where Romex Installation Is Allowed

Under the NEC, Romex is for small residential buildings only.

Though not applicable to most home electrical situations, it is worth noting that Romex is not permitted in commercial buildings or in homes that are triple-story or higher.

Installing Romex Safely: Golden Rules

Following the NEC requirement that Romex should not be left exposed, here are a few golden rules to follow when installing this type of wiring in your home:

  1. Prevent puncturing, scratches, and dents.
  2. Don’t let the wiring get wet.
  3. Avoid temperature extremes.
  4. Keep insulation from touching the conductors.
2 electricians in hard hats, gloves, and yellow vests wiring a house that is in the process of being built.
Install Romex safely according to the rules

#1: Prevent Puncturing, Scratches, And Dents

Romex is not for heavy-duty use and is easily damaged.

Especially if the wiring is running through living areas, secure the wiring beyond easy reach to prevent Romex from being:

  • scratched
  • punctured
  • dented

Where possible, it’s advantageous to install Romex within a conduit or wall interiors, which protects the wiring from damage. PVC conduits, sold on Amazon, are ideal for this purpose due to their robust strength.

When securing Romex, ensure that the fasteners aren’t bound too tightly because they might cut into the wire.

#2: Don’t Let The Wiring Get Wet

Though water resistant and rated for damp conditions, it is vital to ensure that Romex is kept dry. Do not install Romex outdoors or in areas of the home where there is a risk of flooding.

Using conduit is advisable if there is a potential risk that a section of Romex might encounter excessive moisture. The most effective conduit material for protecting Romex from water damage is called electrical non-metallic tubing. This protective tubing lacks the toughness of PVC but has higher water resistance

HOT TIP: Laying the wiring overhead or behind walls also mitigates the risk of water damage.

#3: Avoid Temperature Extremes

Romex is not for extreme heat or cold. When exposed to excessively high or low temperatures, or dramatic fluctuations, the plastic sheathing is liable to develop tiny cracks that jeopardize the efficacy and safety of the wiring.

Laying Romex with insulation protects the conductors effectively from extreme heat or freezing temperatures. Insulation is particularly advantageous when installing Romex where the most significant temperature fluctuations occur:

  • garages
  • basements
  • attics
  • exterior walls

#4: Keep Insulation From Touching The Conductors

Using insulation is one of the most effective ways to protect Romex and ensure it is not exposed to potential sources of damage.

If the insulation comes into contact with the non-metallic sheath of Romex wiring, it does not pose any hazards. However, it is critical to prevent the insulation from touching the copper conductor wires within the sheath. This problem might occur when the wiring is:

  • corroded
  • cut
  • punctured

Protecting Romex In Different Parts Of The Home

Provided that the wiring is not left exposed, Romex is suitable for connecting electrical circuits throughout the home, including the:

  • basement
  • garage
  • attic
  • kitchen
  • primary living areas

#1: Garages And Basements

When installed in garages and basements, it is advantageous to use insulation because these parts of the home are subject to more significant temperature fluctuations than others.

NOTE: If Romex is laid along the exterior of a wall and exposed to damage, the wiring must be installed with a conduit.

#2: Attics

Similar recommendations apply when using Romex in attics, which also experience more extreme temperature fluctuations than the rest of the home interior.

Romex in attics requires the protective shielding of conduit unless you install the wiring behind drywall or plywood panels.

#3: Busy Living Areas

As discussed earlier, Romex requires protection from walls or conduits when the wiring is in parts of the home where it might get damaged by people or animals.

A dog with a chewed up wire in its mouth and on the floor next to it.
Romex must be protected from damage in busy living areas

#4: Cabinets And Crawl Spaces

Romex is suitable for use in confined areas like cabinets and crawl spaces. However, if you are connecting a lighting system in a cabinet or an outlet in a crawl space, it is crucial to install the wiring with a conduit.


Romex is a ubiquitous type of wiring in indoor home electrical applications. This wire is typically for connecting appliances and outlet circuits.

Romex is safe to install in most parts of residential dwellings, including the:

  • garage
  • basement
  • attic
  • walls
  • ceilings

Nonetheless, to install Romex safely and comply with NEC regulations, never leave this electrical conductor exposed in any part of your home.

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