How to Install Wire in Closed Wall

Is there an easy way to install electrical wire in a closed wall?

I think that once you accept the fact that there will be some cutting and drilling and drywall dust ahead of you, you’ll be okay. But it’s no walk in the park.

There are a number of ways to extend electrical wire along a wall. You can install PVC or metal conduit on the outside of the wall and feed the wire through the conduit. But you won’t be working with friendly ol’ Romex wire. You’ll be dealing with THHN (Thermoplastic High Heat-resistant Nylon) coated wire, which are separate strands of wire. THHN isn’t really all that hard to work with, but it’s unique if you’re accustomed to dealing with Romex.

So, both the conduit method and the in-wall method have major pros and cons. Here, we’re dealing just with retroactively installing electric wire in a closed wall. By “closed,” we mean a wall that already has drywall installed.

1. Find the Studs in the Wall

Find Studs in the Wall

I rarely use an electronic stud-finder anymore, preferring a magnetic type of stud finder. This stud finder uses super-strong rare earth magnets to find the nails or screws holding the drywall to the studs.

Find studs on either side. They will be most likely 16 inches apart.

2. Mark a Square for Cutting

Mark a Square Between Studs

Here I am using a box top to mark out a square for cutting. The square needs to be big enough for you to fit your cordless drill into. Other than that, any shape or size is fine.

3. Cut Out Hole with Reciprocating Saw

Cut Out Square with Reciprocating Saw

Cut out the square with the reciprocating saw. Here, I am cutting out a door hinged on the left side. I have cut only three size of the square, leaving the left side uncut. You’ll see why I did this later.

4. Use Screwdrivers to Get a Grip on Drywall “Door”

How to Pull Out Drywall Door

Another type of “door” you can cut is hinged on the bottom. Again, whatever works best for you.

Neatness doesn’t really matter, since you’ll be drywalling over your cuts.

5.  Snap Drywall “Door” Down

Drywall Door Hinges Downward

With the “hinge on the bottom” version, I simply swing the “door” down until I snap the drywall off.  But be careful not to rip the paper hinge; leave this intact.

6.  Option:  The Hinge on the Side Version

Drywall Door Hinged on the Side

Or, you can hinge the “door” to the side.  Whatever works.  This “snap” was a lot cleaner than the one in the previous step, for some reason or another.

7.   Drill Hole in Stud

Drill Hole in Stud

Drill a hole for your Romex wire with a 1/2″ or 3/4″ spade bit.

8.  Push Wire Through Stud

Push Wire Through Hole in Stud

Slide the wire through the hole in the stud.