Running new wire is the most difficult part of any electrical project. Running wire from a new lighting outlet box or receptacle device box to the fuse box or circuit breaker panel requires fishing the wire through finished walls, floors and ceilings while doing minimal damage to the finished structure. This is always a tricky situation, even for the professional electrician. It is labour-intensive, time-consuming and frustrating at best. Murphy's Law will always come into play when running wire in a finished structure. Always allow yourself more time than you think you will need to do a job.
Obtain a wiring permit from your municipal building permits department. Do not start this project until you have the wiring permit and have posted it on the premises.
Run the wire through holes drilled through the ceiling or floor joists (framing members), or run the wire along the sides of the joists. Drill the holes using a 5/8-inch spade bit. Drill the holes so that the nearest edge of the hole is at least 1 1/4 inches back from the nearest edge of the joist. The hole setback is a National Electric Code minimum requirement, and the inspector will check for a violation of this distance.
Staple the wires along the sides of the joists so that the nearest wire is at least 1 1/4 inches back from the nearest edges of the joists. This setback, like the hole setback, is a minimum code requirement. If you are running several cables along the same joist, you may want to use cable stackers, special straps that allow you to place one cable atop another. Secure the cable at 54-inch intervals and within 8 inches of any device box, lighting outlet box or junction box. A maximum of 54 inches and 8-inch spacing of staples are also a code requirement.
Attach a steel nailing plate to the face of the joists to protect the wire when the minimum setback distance cannot be maintained. Using a steel nailing plate satisfies the code requirements.
Obtain a permit and post it.
Remove all the baseboards in the room. There are several methods for running new wire in a finished room but running it behind baseboards is the easiest and causes minimal damage to the room's finish. Cut the paint bead between the top of the baseboards and the wall with the razor knife. Work the putty knife and flat pry bar behind the baseboard and pry the baseboard away from the wall. The putty knife protects the wall finish from being damaged by the pry bar.
Snap two lines 2 inches apart behind the baseboards for the full length of each wall with the chalk line. Drill 1/2-inch holes in each corner of the outline and remove the cut out with the portable jigsaw. The jigsaw will cut through the wall studs to a depth of about 1-inch, setting the height of the notches to be made in the wall studs. The upper and lower cut lines set the upper and lower limits of the notches through each wall stud. Remove the section of the notch between the cut lines with a wood chisel.
Complete the notches with a wood chisel. Lay the wire in the notches and cover with nailing plates.
Drill 5/8-inch holes down through the wall's base plate to feed the wire down into the basement. Drill 5/8-inch holes down through the wall's top plate to feed the wire down into the wall cavity from the attic and then through the wall's base plate to reach the basement from the attic.
Things you need
- 3/8-inch drill/driver
- Spade bits
- Tape measure
- Nonmetallic clad cable (Romex)
- Nailing plates
- Cable staples
- Razor knife
- 4-inch wide putty knife
- Flat pry bar
- 1-inch finish nails
- Chalk line
- Portable electric jigsaw