If you're tired of stringing an extension cord across the garage every time you want to vacuum out the car or belt-sand a board, install a new wall outlet, or duplex receptacle.
In our garage, we tapped into a ceiling outlet to provide power to the new wall outlet. We ran ½-inch-diameter, thin-wall metal tubing, or conduit, across the ceiling and down the wall. (Conduit is sold in various lengths for about 20 cents per linear foot; it's also referred to as EMT, for electrical metallic tubing.) To bend conduit, electricians use a simple hand tool called a conduit bender. We took the easy way out and bought preformed 90-degree conduit elbows ($2 each).
Once the conduit is installed in your garage, push three 12-gauge, single-strand copper wires (25 cents per foot) through the tubing. There should be one white wire, one black wire, and one green grounding wire. At the end of the conduit, install a 4-inch-square metal box ($2.30) and two duplex outlets. As the illustration shows, one of the outlets is a GFCI, or ground-fault circuit interrupter outlet ($10), the other a standard grounded outlet ($2); they're wired so ground-fault protection is provided for both. Note that one white wire goes from the top, left-side terminal screw on the standard outlet to the top, left-side "load" terminal on the GFCI.
The black wire takes a similar route from the top, right-side terminal screw on the standard outlet to the top, right-side "load" terminal on the GFCI. The long, continuous ground wire runs from the metal box to the GFCI and then to the outlet.
According to the National Electrical Code, all garage-wall outlets must be GFCI outlets or standard outlets protected by GFCI circuit breakers.
- Conduit connectors must be used to secure thin-wall conduit to metal boxes.
- Garage-wall receptacle outlets must be protected by a GFCI at the outlet or by ground-fault circuit interrupters in the main service panel. All metal boxes must be properly grounded.