Outdoor Improvements
Outdoor wiring additions most often include GFCI protected receptacles and light fixtures either 120 volt or low voltage or both.
Wiring an Outdoor Receptacle
According to present electrical codes, any new outside receptacle (such as one used to plug in a patio charcoal starter, a patio heater, or a radio) must be protected with a GFCI. To make your job easier, you can buy a complete kit consisting of a cast aluminum outdoor box and cover and a GFCI receptacle.
A pump or filter for an aboveground pool, a hot tub, or a garden pond or fountain is also usually cord connected to an outdoor receptacle. You should use these devices only on a GFCI protected circuit, even if your home was built before GFCIs were required. If the device isn’t already equipped with a locking plug, it’s recommended that you install one; then wire a matching locking receptacle that’s protected by a GFCI-type circuit breaker.
After wiring an outdoor receptacle, install a gasket in combination with a plastic shield to keep out any moisture.
Cable and conduit
Outdoor rooms are casual, so exposed conduit may not be considered unsightly. Plastic (PVC) conduit is pretty rugged, but metal conduit is more resistant to hard knocks. Consider installing metal wherever it might get bumped-for example, by a lawn mower. Codes prohibit exposed cable outdoors, because it can be easily damaged.
Always use approved UF cable for outside wiring. Though resistant to moisture, UF cable is vulnerable to damage from a shovel or hammer, so protect it well. When installing an eaves or porch light, run standard cable through the attic or through a wall. When installing a post light on top of a 4x4, one option is to run the cable through a groove in the post, then cover the groove with a 1x2.
Check for underground utilities when planning trenches for underground cable runs. Avoid lawn sprinkler pipes; and consult your electric utility office, Phone Company, gas and water department, and cable television vendor for the exact locations of underground utility lines. Many utility companies send field representatives to show homeowners how to avoid dangerous underground hazards.