How to run wires through walls horizontally?

How to run wires through walls horizontally?

Johann a TV mounting Technician and Editor
Scroll down to rate and give feedback.
10 min read for expertise

Last Updated on June 7, 2022 by Johann Holsinger

Should you run wire through walls horizontally?

There are many reasons you may need to run a wire horizontally through your walls. Perhaps you are installing a home security system, upgrading existing wires, installing high-speed internet cables, or your home entertainment system.

Whatever your plans may be, there are numerous reasons why running your wires through the walls is beneficial. Good cable management not only looks better aesthetically but can also make use of existing wire paths or create a cleaner safer room to keep your home up to code.

Fishing cables from one end to the other is normally the most time-consuming part of the entire process. But with the right planning, tools, and knowledge you can make this normally difficult task much easier and quicker.

We have looked at many cables and have said to them all. “Your so long were going home.” In all our high-end DIY and home theater renovations. Jokes aside, let’s help you guide your electrical components!

When and why is better to run wires inside a wall?

Running wires behind your drywall is an excellent way to get power right where you need it.

Whether you are running electrical wiring to additional outlets or lighting fixtures, or are snaking audio/visual equipment wiring throughout your house for a complete home entertainment system.

Having wires tucked neatly inside or behind your walls is not only more convenient for wall-mounted units and outlets but looks much better aesthetically as well from our perspective.

Wires inside an electrical box

What are the challenges of running wires through existing walls?

1. Finding the right tools needed

You may end up needing a variety of drill bits, wire feeding tools, different cable types, and bundling options.

Some may already be on hand, while others may need to be purchased in advance.

Tools needed for running wires

2. Detecting stud locations

Studs placed 16 to 24 inches apart are common in the United States. 

Always use a stud finder to be sure of the distance before you start drilling into the drywall.

3. Making sure not to damage pipes or existing wires when not drilling

Always be sure you know exactly what is behind the wall before you even turn on the drill. Existing electrical wires, water, and gas pipes, and result in serious damage and drama.

4. Making a neat runway while being safe

Always use the right size drill bit when drilling holes into studs.

This not only provides plenty of room for your cables but drilling a hole not too big retains your walls’ structural integrity as well.

5. Knowing when to get in & when to get out

Don’t drill multiple holes into a stud just for perfect central placement, this can do more harm than good.

Just drill one small hole for your cables, then move on to the next stud. Make sure to have extra space for the cable to easily be moved upon any tension.

Scopes of running wires through walls

1. Extending a circuit to a new outlet location. As long as your existing circuit can handle additional load safely, adding more wires and an additional outlet location will require the safe installation of wires through the walls.

2. Running a new circuit to a new outlet location.

Setting up an entirely new circuit from your breaker box to a newly placed outlet is another reason you would run wiring through the walls.

Always be sure that you use the proper gauge wiring in this case.

Screwing an outlet for cable

3. Hiding home entertainment cables. Running speaker wires behind the walls is a great way to ensure your home entertainment system looks sleek and clean.

Additionally, this allows you to install speakers in other rooms entirely without having cables on the floor or running through doorways.

Considering your local building code

When drilling into a stud, always ensure the size of the hole will be less than 25% of the width of the load-bearing stud. This ensures you remain within building code regulations [1] and prevents any structural weaknesses.

For non-load bearing studs, the size of the hole should be no more than 25% of the width of the stud. Anything larger can cause weaknesses, wall sag, and cause stud failure over time.

Tools you will need

  • Stud Finder
  • Voltage Tester
  • Drywall Saw
  • Fish Tape
  • Guide Wire
  • Bubble Level
  • Cordless Drill
  • ⅛” and ½” Drill Bits
  • 24” – 72” Flex Bit for Drill

Marking wall with a pencil and a stud finder

How do you check free wall space for running wires?

Using a stud finder can be an excellent way to locate not only the studs but the tool can also help you find the answer to – Where do electrical wires run in walls.

For more precise readings, however, you may want to opt for a MultiScanner or Deep Scan unit. These are similar to stud finders but can detect wire bundles and pipes further into the wall.

Whether you are drilling directly into the wall or drilling wire runs horizontally, ensuring you know exactly where existing electrical wires and pipes are is vital.

When using a MultiScanner or Deep Scan unit, you will notice different tone frequencies and lighted signals for wood and metal studs, as well as bundles of wires, pipes, stud plates, and more.

Planning the wire route

Whether you are starting from a breaker or an existing junction box, make note of your starting point. Once you know where you will begin, make sure you know your final destination.

Will you be running the wire horizontally only, from one outlet to another? Or will you have to run wire vertically to a breaker or junction box? Knowing this in advance will make the entire process much easier.

Take note of how many studs you have to drill into and pass wires through [2].

How a wire is routed on a concrete wall

Also, be sure you know which are load-bearing and which are not since this will determine the size and placement of the hole you can drill to remain within the building code restrictions.

Also, be sure you know what type of insulation may be present in your walls.

Loose insulation can either be light and fluffy or hard-packed which can require adjustments to your wire route.

Points for planning:

  • Studs are normally placed 16 to 24 inches apart, so choose your drill bit length accordingly.
  • If the stud you plan to route the wire through is load-bearing, do not drill a hole larger than 25% of the width of the lumber.

Cutting the entry boxes

Use a stud finder to locate the best place to retrofit your entry box. Try to position the box in such a way that is convenient to access in the future while still being discreet to fit the space.

When cutting drywall to run wires through walls, you may want to use a small level to ensure the box is in a perfect position.

A level is highly recommended for this step as a crooked entry box can cause problems later on with circuit covers and wire frames.

An entry electrical box installed on a drywall

Use a pencil and draw around the outline of the box so you know exactly where to cut.

Remove the box and use a scoring tool to cut slightly into the drywall.

This will help prevent unnecessary cracking and fraying when you use a drywall saw to complete the cut.

Use a pencil and draw around the outline of the box so you know exactly where to cut.

Remove the box and use a scoring tool to cut slightly into the drywall.

This will help prevent unnecessary cracking and fraying when you use a drywall saw to complete the cut.


More to Note:

  • Drilling a hole in a corner of the box outline can help you get started with the drywall saw.
  • Don’t worry about leaving a rough cut in your drywall. The entry box will have a cover plate with an extending flange to cover this up when finished.

Drilling into studs

Find the studs with a stud finder, by knocking on the wall, or any of these ways. Stud finders are affordable and useful devices you can find one at any home improvement store or online. You can also try knocking on the wall and listening to hear whether each tap sounds hollow or solid.

Ensure your drill bit is the right size and length to reach the stud.

If you are only going a short distance, a 12-inch drill bit may be plenty at a sharp angle. However, you can find flex-bits in lengths of up to 72 inches.

Drilling into bare studs

If you need to drill through multiple wall studs when running wires through walls horizontally, you may need to cut out a small area of the plasterboard next to each stud you have marked to drill through each one,

After threading the wires through each stud you will need to patch up the plasterboard holes, and re-plaster and paint them.

Drill as close to the center of the stud as possible.

This is much easier with a flexible bit shank by adding leverage pressure on the drill end of the bit.

If you’re using a long drill bit, continue to the next stud and repeat the previous step until you have reached the other outlet hole.

From your drilling angle, you will slightly curve towards the center of the stud where you are drilling your holes.

When finished, remove the drill bit slowly using the reverse function on the drill to prevent snags when passing back through the studs.

Take Note:

  • Load bearing studs should have holes drilled as close to the center as possible, and be no more than 25% of the width of the wood. Ideally only 10%.
  • Non-load bearing studs can have holes drilled off-center, but should still remain less than 25% the width of the wood.

Threading and fishing the cable wire through each wall stud

Tools to fish wires through walls:

A guidewire.  Can use an old coat hanger for this.

A powerful earth magnet. Cover the earth rock with a soft fabric so as not to damage or scratch your walls. A strong magnet can be found online, or inside an old computer hard drive.

A guidewire. To connect the wire and guidewire.

Different electrical wire colors

Threading and fishing the cable wire from an outlet entry through your drilled holes in the studs can end up being the most difficult part of the whole process.

However, some select tools can make the process easier.

By having your cable attached to either a guidewire or pole, you can secure the cable to the end of the pole and push the wires through the drilled holes and insulation.

Additionally, the best way to fish wires through walls is to use a magnetized tool to not only find your wire from behind drywall but to guide the cables to the outlet opening as well.


  • Having electrical tape on hand to secure your wire to the fish pole or guidewire will help ensure the wire stays in place when threading and does not get caught on insulation.
  • Threading wire through hard-packed insulation can be done by repeatedly jabbing a path with a rigid fish pole, or by use of a magnetized threading leader.

Fixing the wire to the outlet/ electrical box

Always ensure there is no residual power running to or from the electrical outlet you will be working from by using a voltage meter.

After this quick safety check, remove the old faceplate and outlet from the wall. 

From there, you will fish or guide the new wires to the outlet hole, running them through the wiring hole to your new outlet.

Always be sure to properly ground your new outlet with the bare wire attached to a grounding point on the outlet.


In standard electrical wiring for outlets in America, the black wire is your live or hot wire and should connect to the silver screw on the outlet. (This will vary in other countries)

Neutral wires are white and will connect to a silver screw.

The bare copper wire is a grounding wire and should have a designated spot on the side of most outlets. Check both sides to be sure.

What if there’s a firewall?

You may occasionally encounter a horizontal beam of fireproof boarding running between the wall studs, or as a plasterboard layer.

This is a firewall or fire block and the purpose is to help prevent the spread of fire from upper or lower clusters of electrical wiring within your walls.
The easiest and proper way to run wires and to deal with a horizontal firewall is to ensure you drill your wire holes in front of it.

Take note if you make any penetrations through a firewall designed to limit the spread of a fire, you need to seal the holes through the fireproofing surface with a fire retardant silicone.

 Can you run wires behind studs instead?

Any wires should not be run behind studs between wall linings and timber at all.

Cables and wires are much safer when you drill holes into the center of the studs and guide your cable bundles through the designated holes that are the right size.

This not only provides ample air circulation around the wiring to prevent any heat buildup but will also keep your wall linings flat without any bulges.

And also prevents any friction damage to the wires which can become a fire risk over time.

How close can wires be when running through walls?

If you will be bundling wires of the same or similar type together, such as low voltage and ethernet, for example, they can all be touched and fished through the same hole safely.

If you will be installing line voltage in addition to low voltage home theater wires, we highly recommended you keep at least 6 inches distance between them.

This prevents interference with electrical equipment and reduces the risk of fire.

How to drill holes in intermediate studs for long distances?

Intermediate studs are normally placed 3-thick side by side and can include top and bottom nail plates.

Similar to drilling through both load-bearing and non-load bearing studs elsewhere, the holes drilled in intermediate studs should be no more than 1/4th the width of the stud.

Always use a stud finder or deep wall multi-scanner unit to check for existing cable bundles or pipes as they are commonly routed through intermediate studs.

When do you need to remove wall linings and run wires horizontally?

You will rarely need to completely remove wall linings to run wires from one outlet to another.

In cases when you do need full access to open drywall to run wires through walls.

You could need to avoid a large number of existing cables or pipes in the wall from the original build or a previous remodel.

Hidden studs revealed inside a room

Wires are safe when hidden

Regardless of the reasons why you need to run wires behind your wall, ensuring you have the proper tools and knowledge beforehand can make the process not only easy but safe too.

As confirmed wires and cables belong best in their home – that is safe inside your walls, not dangling around.

Being sure to avoid existing wires or pipes while maintaining the structural integrity of your studs is the biggest thing to take notice of. Once that is done, you’ll soon be creating a new outlet or installing electrical equipment like a professional!

More information:

  1. How to run electrical wires in a finished wall?
  2. How to run wires through walls,

How helpful is this guide?

Click on a star to rate our findings!

Happy to hear this helped you! Please don't forget to follow Mountyourbox on


We are sorry that this post was not useful for you!

Let us improve this post!

Please tell us how we can improve this post?

Johann Holsinger portrait

Hi, my name is Johann Holsinger, here at I share all of the tips and tricks I have professionally learned to help you set up your ultimate home entertainment system.