Installing an Electrical Outlet on a Masonry Wall

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I live in an old house and the largest portion of our house sits on a stone foundation. And a few weeks back I told you about my in patio lighting project. I’ll focus a little today on installing a new outlet for the transformer that would drive that lighting.

I have shared some of the electrical projects we’ve done around here. Frankly though, that single post doesn’t even scratch the surface. I’ve actually done a good bit of electrical work through the years, and honestly it is something I really do enjoy.

Going against specification somewhat, I mounted my pack indoors. I set it in the small room that sits under our side porch (I wrote about that there). While I had previously called this room our mechanical room that really isn’t a fair distinction. Our breaker panel as well as the command board for our security system is installed here. Beyond that, there’s really not much else – a little space for storage.

Because of its proximity to the patio, its relationship to the lights in my lighting plan, and its present function, this location was simply the right place to install my power pack. With it, consequently, my new outlet.

 

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Installing an Electrical Outlet on a Stone Wall

* Prep

First things first, I placed the box on the wall roughly where I wanted it to go. One of the more challenging parts of my task was that in my house, and at some point over the last 120+ years, the stone wall in this room had been parged over with something. I wanted to find the mortar joints to make an easy installation of a box. Simply plug things in and be forgotten. BUT I just couldn’t see the mortar joints in this wall, as they again were hidden behind that parging.

So I had to probe. Mindful of the power pack’s chord length and the handy box’s size, I moved around until I found an exact location that would work. I loaded up my drill driver with a masonry bit 3/32″ I believe) and I got busy. My first drilling was a success and I pre-drilled to depth of about 2”. I backed out the bit, clearing the debris about 3 times or so as I went.

Now, I know some readers, even to this point, could be intimidated by the thought of screwing something into to a stone, brick or a block wall. And yeah, that task has gotten the best of me on several occasions in the past.

“Don’t you need special screws for screwing into masonry, a special bit, and special instructions?”

Well, yes, as I noted in my recent post on common screws, IF you are going directly into stone, brick, block or even into concrete. But it is not an absolute necessity if you are only going into mortar. (Note of caution there though: If you are installing something in either mortar and/or that primary block, brick or stone surface and it will bear significant weight , see instead lags and shields.)

For my outlet installation, I used 2 ¼” #9 epoxy-coated backerboard screws. Their relatively thin shaft went in easy, and their hi-lo thread configuration really bit in to hold. You certainly select your own screw, but I recommend one with similar propeties.

Hookin’ Up Your Electrical Outlet

* Before Mounting, Prepare the Handy Box

It’s much like installing a metal junction box. This box has knockouts so I removed one. for where my wire would enter and attached an EMT termination fitting. It was at this point that I also adding my vertical length of EMT (electrical metallic tubing). Because the handy box is metal, it’s pretty essential – I installed a ground screw with a factory-mounted grounding wire. This would tie easily into the receptacle’s grounding screw when I was ready.

Tip: As an adding grounding measure remove the square plastic nuts that held the outlet’s mounting screws.

* Mounting the Box and Pulling Wire

I feed my wire down through the vertical stand of EMT. I used one screw to screw the box in and being careful not to overdrive it. Using a torpedo level, and though a quick “does it look level?” works just as well, I marked for, drilled and installed a second screw.  I then strapped the rise of tubing to the wall about 24″ above the outlet (for this, I used more traditional 2 3/4″ Tapcons.)

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While I had said previous that I wired off of our alarm circuit, actually I pulled my new wire over from a keyless light mounted on the porch joists. It was easy for me to quickly shut off the associated breaker. I ran my new wire along the ceiling feeding it through the EMT.

* Cutting EMT

While you can use a hack saw, an angle grinder loaded with a metal cut-off blade or even a chop saw, I chose to cut my tubing with the tube cutter I typical use with cutting copper plumbing pipes.

With flush mounted boxes (similar to old work boxes), it is necessary to remove the receptacle’s “ears”, I used my Klein Tools Side Cutters to easily break them off.

* Connecting the Outlet

I prepped the wire, and back-stabbed my outlet. Here – ground first, neutral (or white) second – always to the silver screw side, and finally the black side, last.

Maybe a little anal but in metal boxes it is sometimes common to wrap the terminals with electrical tape … kinda like wrapping a toothache (if you picture the image I mean). I did this once the screw terminals were screwed down.

* Attach Outlet and Add Cover

I attached the receptacle to the box and installed the cover (with pre-fitted screw).

* Finishing Up

I circled back made my connections at my light, flipped the breaker on and plugged in my power pack. Done and done, the whole operation took me about an hour of working time.

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For more info about wiring outlets, you could see this article from The Art of Manliness – How to Wire an Outlet. That’s it. Thanks for joining me today, hope it helps. May your week be … electrifying and great. ~jb