How to Wire in Electricity in a House
Wiring your own electricity is a challenging, yet do-able, project that can save you thousands of dollars. An older home may have a combination of wiring, some of which may have been improperly installed, creating a safety hazard. You can pay a qualified licensed electrician to create your electrical plan, and do the actual work of wiring yourself. If you understand the basic principles of electricity, you can create your own electrical plan. Either way, it is essential to have a plan that addresses all code issues and construction methods before you start work.
How to Wire Electricity in a House
Review your electrical plan and make a list of supplies. Determine how much wire you need in each gauge, how many boxes, outlets and switches. Generally, 14-2 or 14-3 gauge is used for lights and switches, 12-2 for outlets and 10-3 for electric ovens, dryers and such. Electrical wiring is easier to do before drywall is installed. If you are rewiring an existing home, decide if you will fish wire through the walls, or remove drywall and patch after the electrical wiring is installed. In many older homes, framing cross supports make it difficult to fish wire.
Nail a single, double or triple box to the closest stud in each location noted on your plans. Outlets should be approximately 18 inches from the floor. Switches should be located at a comfortable height, approx 42 inches. When rewiring, determine if existing boxes are sufficient, or if you wish to move or add boxes. Attach a ceiling box to an overhead joist for each overhead light fixture, using proper support brackets for ceiling fans.
Near the first box in the run, drill a ½- to 1-inch hole in the header for attic wiring, or footer for basement or crawl space wiring. To wire to subsequent boxes, drill each vertical stud between the boxes about one foot above or below the box. Install a nail plate on each side of these holes to prevent nails from hitting wiring.
Lay the spool of wire at the panel box. Thread wire through the header or footer and pull to the first box. It is extremely helpful to have a second person feed the wire. Fasten with wire staples every three feet along the run, and within 12 inches of each box. Cut the wire and run a new section of wire for each box in the run, leaving approximately eight inches on each end. Thread wire through the vertical holes, to the next box. Note: If you are fishing the wire, insert the fish tape through the wall and above the ceiling or below the floor. Loop the wire around the fish tape, and pull back through the wall to the box.
Cut the outer sheath of the wire, leaving about 1 inch at the back of the box. Use wire stripper to remove 1/2 inch of insulation from each hot and neutral wire. If there are more sets of wire in the box than receptacles, you may pigtail the wires. Cut a piece of wire about 6 inches long. Strip 1/2 inch from each end. Securely fasten the wires in the box, plus the 6-inch section together with a wire nut. Fasten the other end to the receptacle. Crimp ground wires together and cut on just below the crimp. Note: switches have two hot wires and no neutral wires. Make it known that the white neutral wire is “hot” by marking it black, either with tape or a permanent marker.
Using the needle nose pliers, make a hook on the end of each wire. Install the receptacles by connecting the hook of hot wires to brass screws, neutral wires to silver screws and the ground wire to the grey or black screw. Tighten each screw to firmly hold the wire. Using the screws at the top and bottom, screw receptacle into the box. Note: light fixtures should be installed at this time, however there are many wiring configurations, depending on how many lights and/or switches are tied together. It is recommended to consult a qualified electrician or obtain detailed information from the lighting's owners manual.
After all wire is run, wire the panel box. Cut wire to length, plus about 12 inches. Strip the outer sheath to about 4 inches inside the box. Strip 1/2 inch off each hot and neutral wire. Neatly attach each hot wire to a breaker, each neutral wire to the neutral bar, and each ground wire to the ground bar. Turn on the main breaker, the individual breakers and test each run.