Most homes are built with all the necessary electrical switches, outlets and wiring in place, but even careful planners can’t foresee every need or imagine where future owners may want to hang an extra fixture or add an outlet.
Installing a new wall switch or outlet receptacle box can be a simple, three-step project: Run an electrical line to the location, install a retrofit-type box, then make the wiring connections to the receptacle and the power source. You need only basic homeowner skills and tools to complete steps one and two, and simple wiring connections are within the scope of anyone with rudimentary knowledge of electrical work. If you’re not comfortable making wiring connections, you can have an electrician handle this task after you’ve done the installation steps, typically at considerable cost savings.
Complications usually include blockages in walls or other obstacles between the power source and receptacle, including solid log walls that must be bored or channeled to create a path for the wiring. Electricians and professional remodelers have the tools they need to overcome these problems, such as extra-long drill bits, which are available at electrical suppliers. Sold in lengths up to several feet, these handy bits include a clip that is attached at the tip to pull wires back through the bored hole.
Whenever you work with electricity, research your project thoroughly and keep an electrical handbook handy to ensure that you follow proper procedures. It’s also smart to discuss your installation with your supplier to ensure that you buy the right size and type wire and receptacles. And to be safe, all electrical work should be inspected afterward by a qualified professional.
- Plan your route. Whenever possible, locate your switch or outlet near a wall’s edge, such as close to a doorway or floor, to make it easier to run and conceal the wiring. (Switches are typically positioned 6 inches in from door jambs, and outlets are placed 12 to 14 inches above the floor.) This is especially important for retrofits in full-log walls. A fixture located in the center of a wall will require a long extension drill bit, careful measurements and more work to install. If the wall is accessible from an attic, basement or crawl space, a long drill bit may allow you to drill directly up or down to the box location or to a convenient recess, such as a door- or window-jamb cavity. Surface wiring runs can be concealed behind baseboards or jamb casings, which are easy to remove and replace.
- Cut the hole for the electrical box. Wiring connections for all electrical fixtures must be done within an approved junction or receptacle box. Scribe your box’s outline on the wall, then bore holes inside the lines to the box depth, using a spade or Forstner-type drill bit. Remove the remaining waste wood up to the lines with a hammer and chisel. Metal and plastic retrofit boxes have tabs to anchor them in hollow walls, but if your location is an exterior full-log wall, you’ll have to adapt a box to secure it in the opening. Side tabs that wedge the box into the opening may work, or you can remove the tabs and screw directly through the back or sides of the box to fasten it to the log wall. Fit the box into the opening, but do not install it just yet.
- Bore holes for wiring. Use a ¾-inch spade-type drill bit to bore holes to the box location. For boxes placed near a wall edge or access cavity, a short bit extension may be all that is needed. The extra-long extension bits that electricians use are typically flexible and can be "guided" to their target using a special handle, but this requires considerable dexterity and practice. Renovation work also requires creativity to overcome obstacles. To run wires from a door-jamb cavity to the box, for example, you can remove the lock strike plate and bore horizontally through the jamb. The strike plate will hide the hole when you replace it.
- Run the wiring to the box. Most installations will require 12-gauge, 2-wire cable with a ground wire (designated 12/2 Type-NM, or non-metallic). Rout the cable from your power source, which can be the home’s main circuit panel or any convenient junction box such as another outlet or switch box, to the new box location. Although the cable is flexible, it can be difficult to coax through narrow or hard-to-reach openings, and it’s often helpful to use a wire "fish tape" or rod to snake the cable from one point to the next.
- Connect and install the receptacle. When you have completed the wiring run, secure the cable in the new electrical box and make your wiring connections at the receptacle. Follow the directions provided — receptacles may be connected in various ways depending on the situation, so be certain to choose the correct wiring diagram for your installation. Wrap each wire approximately three-quarters of the way around each terminal screw, and firmly tighten the screws. Be sure to connect the cable’s ground wire to the (metal) box or to the green ground screw provided on the receptacle.
- Complete the wiring at the power source. Connect the new cable wires to the power source. Before you begin, shut off power to the circuit to which you are connecting, or turn off the home’s main breaker at the circuit panel. If you are tapping power from another receptacle or fixture, use wire nuts to secure each connection. When everything is complete, restore power and use an electrical tester to check all fixtures and receptacles.