Installing an outdoor electrical outlet allows you to power outdoor lighting, appliances, tools and more, greatly increasing the functionality and enjoyment of your outdoor living space. While it may seem daunting, installing an outdoor outlet is a manageable project for most DIYers. With proper planning and by following electrical codes, you can safely and successfully install an outdoor GFCI outlet.
Things You’ll Need
Before starting this project, make sure you have all the necessary materials and tools:
- Outdoor GFCI outlet
- Weatherproof electrical box
- Weatherproof cover plate
- Outdoor-rated NM-B electrical wire or UF-B wire
- Wire staples or cable clamps
- Wire strippers
- Screwdrivers
- Voltage tester
- Multimeter
- Hammer drill with masonry bit (if installing in brick, concrete, etc.)
- Shovel
- PPE – safety glasses, gloves, etc.
Choosing a Location
When deciding where to place your outdoor GFCI outlet, keep these tips in mind:
- Pick a spot close to where you want to use power – patios, decks, gardens, etc.
- The outlet must be accessible and not blocked by vegetation, structures, furniture, etc.
- Avoid locations that will expose the outlet to constant moisture from irrigation, rain runoff, etc. Overhangs and eaves provide protection.
- Do not install directly on the ground where it may get submerged in water. Elevate at least 12 inches above the ground.
- The box should be positioned vertically, with the outlet face pointing downwards.
- Outdoor outlets must be at least 10 feet away from pools and hot tubs.
Also consider how you’ll route the wiring from the indoor electrical panel to the outlet. Avoid long wiring runs for safety and efficiency.
Turn Off Power
Before doing any work, turn off power to the circuit you’ll be connecting the outdoor outlet to. For whole house work, turn off the main breaker. Use a non-contact voltage tester to double-check that power is off.
Install Electrical Box
Mount an outdoor-rated, weatherproof electrical box at your planned outlet location. PVC or metal boxes are good options. You can attach it to the exterior wall of your home or other solid mounting surface like a post using appropriate screws or anchors. The box should be installed vertically with the open side facing downwards.
If running wiring through an exterior wall, drill holes with a masonry bit and thread wires into the box. For surface-mounted conduit, secure conduit box connectors to the electrical box.
Keep the box close to the mounting surface – don’t allow more than 1/4″ space behind it. Seal any gaps with silicone caulk to prevent moisture intrusion.
Run Wiring
Run the electrical wiring between the indoor panel and the outdoor outlet box. Here are some options:
- Through the wall – Drill holes through the wall’s rim joist or sill plate. Protect cables with conduit when passing through cinder blocks or concrete.
- Surface conduit – Run wiring through exterior-rated metal or PVC conduit mounted on the exterior wall surface. Secure with appropriate conduit straps and fittings.
- Underground conduit – For underground wiring runs, bury schedule 40 PVC or rigid metal conduit at least 18 inches below grade. Use sweeping 90° elbows to prevent cable damage when pulling.
UF-B underground feeder cable can be buried without conduit if buried deep enough. NM-B can only be used indoors unless inside conduit. Use proper wire staples, fasteners and wire clamps when securing cables. Ensure cables are protected from damage.
Connect Wires
Inside the panels, use wire nuts to connect the hot, neutral and ground wires from the electrical cable to the corresponding circuit wires and ground bar. Secure incoming and outgoing cables to prevent strain on connections.
Leave 8-10 inches of extra cable in the outdoor box for easy connections. Use nail guards to protect cables from punctures or scratches. Close up the panels once wiring is complete.
Install GFCI Outlet
At the outdoor box, strip 3/4″ of insulation from the cable using wire strippers. Secure the hot (typically black), neutral (typically white) and ground wires to the corresponding screw terminals on the GFCI outlet using a screwdriver. Follow the manufacturer’s wiring diagram.
Ensure all connections are tight and secure. Attach the weatherproof cover plate over the outlet. Re-check that all connections are covered safely.
Test and Use Outlet
Restore power at the breaker panel and test the outlet. Plug in a lamp or voltage tester appliance. Confirm that the GFCI reset button functions properly. Press the TEST button and ensure power cuts off (and is restored when reset).
Your new outdoor outlet should work just like any GFCI outlet. Keep the cover closed when not in use to prevent moisture damage. Inspect it periodically to ensure it remains in good condition. Avoid overloading with too many appliances or decorations. Enjoy your new outdoor power source!
Outdoor Outlet Installation Tips
Follow these additional tips for safe, long-lasting outdoor electrical outlets:
- Use outdoor-rated boxes, covers, conduits and wiring for reliability and safety.
- GFCI protection is required by code for all outdoor outlets to prevent lethal shocks.
- Choose weatherproof covers that fully seal off the outlet even when cords are plugged in. In-use covers provide extra protection.
- Caulk around the electrical box to create a waterproof seal to the exterior wall.
- Allow extra slack in the wiring so the outlet can be removed for maintenance.
- Label the breaker supplying the outdoor outlet for easier power shut-off when needed.
- Consider tamper-resistant outlets or boxes to keep the outlet protected.
- Install outdoor outlets at least 12 feet apart to avoid overloading circuits.
- Position outlets upside down to prevent moisture from collecting inside.
- Group outdoor outlets supplied by one circuit on the same GFCI for easier management.
Frequently Asked Questions
Here are answers to some common questions about installing outdoor electrical outlets:
How deep should I bury UF-B underground cable?
UF-B cable must be buried at least 18 inches below grade for protection. Deeper burial of 24-30 inches is ideal.
Can I use NM-B cable outdoors?
NM-B (Romex) is only rated for indoor use unless run through conduit. UF-B or individual THWN wires are better outdoor wiring options.
What size wire should I use?
For 15-20 amp outdoor outlet circuits, use 12 AWG or larger wire for safety. Larger 10 AWG may be preferred for longer wire runs.
Can I install low voltage lighting on the same circuit?
Yes, provided you size the circuit wiring appropriately and use a transformer to step-down to 12V or less for the lights.
Should I use a wall switch or leave the outlet always on?
Most homeowners leave outdoor outlets always powered on. Add a timer or photo sensor switch if you want to control automatically.
How do I add more outlets in the future?
You can daisy chain additional outdoor outlets from the existing GFCI outlet, using appropriate outdoor-rated junction boxes.
How often should I test the GFCI?
Test GFCIs monthly by pressing the “Test” button and confirming power trips off and can be reset. This ensures ground fault protection is working properly.
Conclusion
Adding an outdoor electrical outlet is a worthwhile DIY project that will make your exterior living space much more usable and enjoyable. By using the proper materials, planning the ideal placement, and following electrical codes, you can safely install a new outdoor GFCI outlet in just an afternoon or weekend. Be sure to turn off all power, make secure wire connections in junction boxes, and test the new outlet before regular use. Your outdoor lighting, appliances and power tools will now have a convenient, weatherproof power source to plug into outside your home.