What size Hole is needed for Romex Wires?

There are a lot of technicalities even while drilling a small hole in joists and you might also wonder what size hole for Romex there should be for a safe and secure electrical system.

How to drill a hole? What is Romex and how is it used? We will answer all questions in this blog.

First, let’s learn about what Romex is. It is an electrical cable typically for wiring electronic systems, different outlets, switches, and panels. There are different Romex types like a 12-gauge and 14-gauge wire based on the size of the gauge and two or three insulated wires enclosed in a single covering.

Nowadays, in most cases, we don’t have a 14-gauge wire in homes because of specific codes and safety measures while a 12-gauge wire is normally used in homes for wiring branch circuits. The wire is passed through the hole in the joist before hanging the wall on top to make a secure connection and to provide an electrical supply to the switches.

How should we Drill the hole?

The whole concept and practical use of drilling a hole with a specific depth is because if the hole is bigger it might result in bending or breaking of the wires resulting in electrical faults and even hazards. Otherwise, If the whole is smaller, it will be difficult to pass the wire to make a connection for the electrical supply in the space. 

How much hole for the Romex?

According to the specific electrical codes and standards, A 12-3 gauge wire requires a hole of about ¾ inch of diameter while a 5/8 inch hole is recommended for a 14-gauge wire. 

This is the preferred diameter because the appropriate depth helps in maintaining a distance of screws and bolts from wires preventing any possible damage to the connections. One thing to keep in mind is not to drill holes again at the same place otherwise It will damage the structure and strength of the joists and holding materials.

There are many other types of Romex like a NMC which is a Non-metallic wire used in damp locations. Others are UF (Underground Feeder) also used for underground damp locations due to durability and flexible use.

 The wires are different also based on the number of copper wires in the sheathing. e.g A 12-3 wire has 4 wires in total out of which three are hot wire and one is ground wire while a 12-2 wire has 3 wires in total with 2 hot wires and one ground wire in a single sheath. The outer covering is of about 13 millimeters PVC which protects the individual conductor wires. The colors are yellow, white, and orange assigned for 12-gauge, 14-gauge, and 10-gauge respectively. 

Tools and Tips 

1. Tools like wire guards are also available to drill a safe and secured hole with an enclosed, insulated cavity preventing any direct contact of screws and bolts during constriction. This can save you from damages and accidents by maintaining a barrier between wires and other materials.
2. Romex wires are used to supply lights and appliances in homes and other spaces with exceptional conductivity throughout.
3. Special Electrical boxes are also available to hold wire ends and extensions in the connections which can installed while incorporating walls and electrical panels during the building process. The holes should be drilled in the middle of the joist with appropriate measurements and not at the end to maintain a sound structure.
4. A 7/8 Aug bit should be used to drill holes of ¾ inch in diameter in the joist and Irwin is one of the brands that have great quality board bits. These bits come in a set of six and can be used for drilling boards and wooden surfaces.
5. Some say that you can pass about 3 Romex wires from a single hole but usually 2 wires are passed through the hole to avoid any breaking or damage to the connecting wires instead.

Safety Tips

We are also mentioning some safety tips here that are important for you to know when you drill a hole in the joists for Romex Wires.

1. While drilling holes it is always recommended to use headgear, glasses, and gloves so that in case of any accident you can avoid injuries
2.  A fire extinguisher is also a must to keep in case of a fire breakout.
3. To detect wires, use a stud finder before making other connections like screwing nuts and screws in the wall. 
4. Use proper utility knives or cutters are required to cut Romex wires for adjusting length and making circuits.

Calculations and Measurement 

There are specific calculation methods and measurements available in the National Electric Codes for various Romex connections to drill proper holes and make wire connections. The exact width of a hole should be a 1 ¼ inch diameter. Also, Running wires through a conduit is not recommended due to overheating risks.”

Romex Wires can be used in drop ceilings with a conduit running through following proper instructions and codes. For commercial purposes, different types of Romex are required to cater to different needs for functioning heavy equipment and machinery.

Other Uses of Romex Wires

Outdoor Uses

They are used in outdoor spaces where there is less exposure to heat and moisture and areas and in places where there is no public passage like in attics and stores. In such places, it is easy to maintain a safe supply of electricity with less or no chances of accident or fatal injury.

Dry Fields

Romex is advised to be used in dry areas where there is no or less moisture. Spaces having moisture or direct contact with water are not advised for the use of these wires.

Domestic Use 

They are used for domestic purposes while building homes and apartments which typically allow one to two- family residential space.

Covered Spaces

They are generally used underneath dry walls or around wooden cardboard, especially in modern design buildings.

Advantages of Romex Wires

Reliable 

The great thing about the Romex wire is that they are durable and reliable enough for making electrical connections in various spaces. They are advised for long-term and heavy-duty connections because they do not overheat and crack until they are exposed to direct heat and moisture. Such wires can be easily used in wiring for lights, appliances, and control panels.

Good for Commercial Use 

Romex wires are also good to use for commercial installations and covering huge spaces like offices and workshops.

Easy to Install

They are quite easy to install under proper instruction provided by an expert and can work wonders for different modern spaces and building structures.

Affordable 

Romex Wires are not costly and are quite budget-friendly. They are available in spools and are used in meters of length while making wiring connections throughout the building space.

Conclusion

The depth of the Romex Wire holes depends upon the use and size of the wire. All these features in Romex Wire make it a great choice for electrical projects and its safe use is a plus whether you are a professional or a DIYer yourself but proper safety measures and codes should be followed while making the use of such Wires.