Install String Lights on a Patio

String lights turn a concrete slab into a room. The difference between a patio that feels like an outdoor dining room and one that feels like a parking spot is often just twenty feet of Edison bulbs hung at the right height. The job itself is straightforward—drill a few holes, run some wire, plug it in—but the details matter. Lights that sag look temporary. Bulbs hung too high disappear. Too low and you're ducking around them with a plate of chicken. The goal is a clean catenary curve, lights that stay put through summer storms, and a space that feels intentional after dark. Most patios offer three mounting options: fascia boards under the roof overhang, fence posts at the perimeter, or freestanding poles planted in the ground. The best systems use galvanized guide wire to support the light strand itself, keeping tension off the electrical connections and letting you replace bulbs without disturbing the structure. Plan for outlets, account for wind load, and install everything as if you're never taking it down—because once it's up and working, you won't want to.

  1. Map your light run and mark mounting points. Walk the perimeter with your string light still in the package to visualize the path. Mark mounting points every 8-10 feet maximum—closer for heavier bulb styles or windy areas. Avoid running lights across doorways or gates. Use a laser level or string line to keep mounting points at consistent height, typically 8-9 feet above the patio surface.
  2. Install screw hooks or eye bolts at each mounting point. Drill pilot holes into fascia boards, fence posts, or wall surfaces at marked locations. For wood, use 3-inch screw hooks turned directly into solid framing. For masonry or stucco, install lag shields first, then thread in eye bolts. Each anchor point should support 15-20 pounds minimum. Test by hanging your full weight carefully before proceeding.
  3. Run galvanized guide wire between mounting points. Cut 1/8-inch galvanized steel cable to span each section with 6 inches extra at each end. Thread through one screw hook, loop back, and secure with two wire clamps. Pull tight by hand to the opposite mounting point, secure with clamps, then tension further using a turnbuckle mid-span or by re-clamping tighter. The wire should be taut but not guitar-string tight—you want minimal sag but some give for thermal expansion.
  4. Attach string lights to the guide wire. Use zip ties or light-duty cable clips every 2-3 feet to suspend the string lights from the guide wire. Start at the outlet end and work outward, keeping the electrical cord relaxed with slight drape between attachment points. Never stretch the cord itself tight—all structural load should transfer to the guide wire, not the wiring inside the light strand.
  5. Install a weatherproof outlet box if needed. If no outdoor outlet exists within cord length, install a GFCI-protected outlet box on the house exterior near the light starting point. Mount a weather-rated box to wall studs, run 12/2 NM-B cable from an interior junction or circuit breaker, and wire to a GFCI outlet. Use an in-use weatherproof cover that closes over the plugged-in cord.
  6. Test the lights and adjust tension. Plug in the lights at dusk and walk the full perimeter checking for bulb outages, uneven spacing, or excessive sag. Adjust guide wire tension with turnbuckles or by re-clamping tighter. Check that no bulbs hang lower than 7 feet above walking surfaces. Verify GFCI function by pressing the test button—lights should cut off immediately.
  7. Secure all cords and add drip loops. Use cable staples or adhesive cord clips to secure the feed cord against the house wall or fence, creating a drip loop just before the outlet so water runs off instead of into the connection. Coil and secure any excess cord length. Apply silicone sealant around any new holes penetrating siding or trim.
  8. Set up automated control. Install a plug-in timer or smart outlet at the power source to automate on/off cycles. Outdoor-rated mechanical timers work reliably for years. Smart plugs allow phone control and scheduling but need WiFi signal outdoors. Set lights to turn on at dusk and off at midnight unless you're regularly outside later.