I put together a large series of electrical roughing-in videos teaching the full process of how to rough-in for electricians.
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This page lists all Rough-In videos & articles for your convenience.
Electrical Rough-In Material List
Before getting into the Electrical Rough-In Series, it’s important to see what electrical materials are required for the rough-in process. Things like wire types, wire connectors, staples, electrical boxes, screws, and some general knowledge of getting started.
Before Mounting Electrical Boxes
The Roughing-In Process consists of looking at electrical prints, marking out icons on studs and their heights (top of box), drilling holes, pulling and stapling wire, and the cutting-in process.
The cutting in process is when we remove the wire jacket of a cable, insert the wires into a junction box, bond the conductor to the box for safety, then splice the wires. When done, we make sure to tuck the wires in neatly into the back of the box so drywallers do not damage the wires.
Before Mounting Electrical Boxes
If the Rough-In Installation is poor, you will have a much harder time in the Finishing stage.
The first step of the Rough-In Process is understanding:
- A.F.F.
- Jobsite Specs
- Install to Top of Box
- Using Electrical Scabs for Spacing
A.F.F. is above finished floor, and is the ACTUAL HEIGHT of your floor. When in the rough-in stage, the floor height can change if they poor concrete, or install extra layers of plywood. This will always be in your electrical prints.. make sure to talk to the Site General!
Jobsite Specs are on the very last pages of your electrical prints. These are UNIQUE to that particular jobsite, and have costed companies THOUSANDS in mistakes over the years. Make sure you understand what that particular electrical engineer is asking!
Top of Box is the easiest approach to installing boxes.. and Electrical Scabs are used to make sure our boxes are never too close to door frames or window trim.
How to Install Single Gang Box
This video teaches how to install a junction box. There’s various types of electrical boxes, like single-gang, double-gang, triple-gang, quadruple-gang.. which means how many devices we can install in a box, which allows more or less wires per box.
How to Offset a Junction Box from the Door Frame (Electrical Scab)
As an apprentice electrician, we are often afraid to take action, because we don’t know what’s allowed, or proper on site. But the most important thing when boxing is making sure your electrical box is never covered, or too close to unrelated items.
With that said, we often use Electrical Scabs to push the box further away from equipment or things like door frames and windows. Remember, the coverplate is much bigger than the electrical box, where if you screw up, you will see a cut cover plate to make things fit.
How to Install a Double Gang Box
A double-gang box allows for two devices, like two plugs, or a mix of one switch and one plug. Additionally, we can have more wires in the box according to electrical code!
If you use a double-gang electrical box with this flange, it’s very important your screw goes in flush, not crooked, otherwise the drywall will buldge near the box, causing the coverplate to not sit flush (or worse.. the drywall can start breaking!)
How to Install a Triple Gang Box
A must-know for electricians is making sure a box with three devices or more is supported on both sides of the box.
You will see in this triple-gang box installation video that I screw the box onto the stud, just like the double-gang box above, but this time, I also screw an electrical scab on the loose side of the box.
This ensures the box is stable when drywall is installed on both sides of the wall, it sandwiches it together. (Sometimes a drywaller will also screw into this electrical scab).
How to Drill Holes for Electrical Wires
Electricians mostly use Auger Bits to drill holes, as they extract the wood chips as you drill, while also be able to chew through nails (which you should avoid, as it does damage the drill bit).
Besides the drill-bits electricians use, it’s more important to think about a wire’s path from electrical panel to electrical box.
Electricians need to think about the whole wire path from beginning to end, and if the wire will be spliced at certain boxes, because you don’t want to come back and drill holes later, as it’s messy, and takes time!
How to Pull Wire for Electricians (Residential)
Residential Electrical wire pulling is much different than Commercial Electrical wire pulling.
In residential, we are often in wood frame, drill lots of holes, and use NMD90 type wire. We typically have no more than 3 wires per hole, and for bigger wires, they often get their own hole, like #10, or #8.
In commercial, we often pull single wire conductors into EMT Pipe, to create sets of wires. It’s quite an involved process, and requires a lot of organization and preparation.
How to Label and Staple Wires
Labelling is SO IMPORTANT to save time as an electrician.
When labelling wires, ALWAYS label both sides of the wire. We do this by either writing on the wire with a permanent marker, or using white tape on the wire, then labelling the white tape.
In a residential setting, we’re often using staples into wood, in a commercial setting, we’re often using straps and screws.
How to Cut-In for Electricians
Cutting-In is a very important part of the roughing-in process.
If you are in a worst-cast scenario, where you don’t have enough time to splice the wires, you need to at least get the wires into the box so you can access the wires once the drywall gets installed.
But in a normal situation, the cutting-in process consists of:
- Stripping wire jacket off the cable and entering the wires into the box
- Bonding the bare wire to the box green bond screw
- Splicing the wires & putting wire nuts on (Marrettes)
- Tucking the wires in neatly into the back of the box
Splice Wires in a Single Gang Box
This video breaks down the whole process of cutting in and splicing a single-gang junction box.
Splice Wires in a Double-Gang Box
This video breaks down the whole process of cutting in and splicing a double-gang junction box. A double-gang box allows for more wires, and gets a bit more technical with all the wires involved!
Conclusion: Roughing-In for Electricians
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Additionally, here’s all Rough-In Series Articles.
I hope this how to do electrical rough-in in a home was valuable to you, and you learned many best practices of residential electricians.
