How To Install Outdoor String Lights

Adding outdoor string lights can completely transform your backyard, creating a cozy, inviting atmosphere perfect for evening get-togethers. This easy DIY project enhances your deck or patio’s ambiance and incorporates practical lighting into your outdoor space.

When a homeowner asked Ask This Old House master electrician Heath Eastman for help dressing up her deck with some outdoor string lights, he knew just what to do to brighten that backyard space. Here’s more step-by-step guidance for a professional and polished result.

Planning Your String Light Installation

Before starting the installation, plan carefully for a smooth process and a beautiful end result. Proper planning avoids unnecessary complications.

Assessing Your Space

Take stock of your outdoor area and gauge the following:

• The size and shape of your deck or patio
• Existing structures or features that could serve as supports for the lights
• Location of your nearest outdoor electrical outlet
• Potential obstacles that might interfere with your light placement

Before purchasing any lights, measure the linear footage of your intended runs. A helpful approach from This Old House Magazine: on graph paper, make a scale drawing of your space and decide where you want the lights to go. Then trail a clothesline or string from your power source to all proposed light locations, marking each change in direction. Make straight runs where possible. Measure the string to figure out exactly how much lighting cable you’ll need to buy.

Choosing the Right Lights

Picking the right string lights is key for style and durability. Think about these factors:

• Bulb spacing: The distance between the bulbs affects how bright the area will be and the overall look.
• Bulb type: Choose energy-saving LED bulbs that will last longer.
• Outdoor rating: Make sure the lights are designed for outdoor use and to handle the weather.
• String length: Measure your space to get the right length of lights.
• Style: Pick a bulb style that fits the look of your outdoor space, like Edison bulbs for a vintage feel or classic round bulbs for a more modern look.

For any outdoor installation, look for fixtures with an Underwriters Laboratories (UL) rating appropriate for the level of exposure. According to This Old House Magazine, dry-rated lights should never be hung outdoors. Damp-rated fixtures are suitable for sheltered porch areas protected from direct water, while wet-rated fixtures use specialized drain holes, seals, and protective gaskets to prevent water from accumulating on live wires — making them the best choice for fully exposed string-light runs.

When choosing bulb spacing, keep in mind that chunky, larger bulbs — like classic C7s or C9s — look best when spaced between 6 and 10 inches apart. Smaller mini-style bulbs should be spaced more tightly together to deliver even illumination without dark spots between them.

Gathering Materials and Tools

Before starting the installation, make sure you have all the necessary materials and tools. Here’s what you’ll need:

• Drill and drill bits
• Exterior-rated string lights
• Ladder
• Level
• Mounting hardware (including brackets, hooks, and fasteners)
• Outdoor smart plug
• Steel support cable (for spanning distances over 20 feet)
• Tape measure
• Wire cutters
• Wrench or socket set

Installing String Light Posts

If you don’t have existing structures to hang the lights, you’ll need to install posts around your deck or patio. Here’s how to set them up.

Checking Existing Posts

If your deck already has posts, use a level to check if they’re straight. This will help you match any new light posts to the existing ones. Adjust the posts as necessary, or shim the light posts out during installation.

Mounting Brackets

After confirming that the existing posts are plumb, secure the light posts:

1. Place the light post brackets against the outside of the deck’s corner post and mark the screw holes with a pencil.
2. Place one bracket a few inches from the top of the corner post and one in the middle.
3. Repeat this on all corners from which lights will hang.
4. Pre-drill pilot holes at each bracket location. Make sure the brackets are lined up and plumb with each other to prevent the posts from being crooked.
5. Attach brackets using exterior decking screws.

This initial setup provides a solid foundation for your new light posts.

Cutting and Installing Posts

To keep things looking neat and to help with water drainage, cut your posts to the right height:

1. Measure the height of your home’s gutters.
2. Cut light posts about 6 inches shorter than the gutter height for proper drainage.
3. Slide the posts into the mounted brackets on the corner rails and place the end bracket at the bottom of the post.
4. Secure the bottom of each post to the deck using washers and fasteners.

Hanging the String Lights

With the posts in place, it’s time to hang your string lights to create a well-lit and inviting outdoor space.

Installing Support Hooks

Create anchor points for your lights by installing support hooks. This step helps you correctly anchor the lights:

1. Mark the locations of the hooks underneath the gutters on the fascia.
2. Where to locate the hooks depends on the design.
3. Use a drill and a bit slightly thinner than the hooks to drill holes in the fascia.
4. Thread the hooks in and tighten, leaving the open part of the hook pointed upward.

These hooks will serve as the primary anchors for your string lights.

Attaching the Lights

Now you can hang the string lights using this process:

1. Install a loop at the end of the cable with the supplied hardware and hook the loop over the first hook against the fascia.
2. Run the cable from hook to hook, installing a loop on the other end to hang it. Don’t cut the cable to length yet.
3. Attach the lights to the steel cable with the built-in loops, zip ties, or hooks that came in the kit.
4. Keep the cable tight for straight runs of lights, or loosen the hardware on the end of the cable to allow the lights to sag a bit.
5. Tighten the hardware once you’re satisfied and cut the cable with wire cutters.

Adding Support Cable (Optional)

If your string lights will span over 20 feet, or if you want extra stability, adding a support cable is a good idea:

1. Use a stainless steel cable with a black coating for durability.
2. Attach the cable to hooks using carabiners or turnbuckles for easy adjustments.
3. Secure the lights to the support cable using UV-rated zip ties or stainless twist ties for long-lasting support.

Powering and Controlling Your Lights

Once your lights are in place, it’s time to power them up and make sure they’re easy to control. You can just plug in the lights and go, or try one of these more creative ideas.

Installing a Smart Plug

To control your lights easily, use a smart plug:

1. Plug a weather-resistant smart plug into your outdoor outlet.
2. Connect your string lights to the smart plug.
3. Follow the manufacturer’s instructions to control the smart outlet with your phone or a remote control.

Programming Light Controls

With a smart plug system, customization is at your fingertips. Here are a few possibilities:

• Turn the lights on or off from your phone or remote.
• Set schedules so that the lights turn on automatically when it gets dark.
• Adjust the lighting to fit your outdoor activities or gatherings.

How It Works: You don’t need smart bulbs to get smart control over your string lights. As demonstrated on a recent This Old House project, a standard smart switch wired in place of a regular switch can control ordinary bulbs through an app — giving you the ability to set schedules so lights turn on at sunset and off at midnight, without any special bulbs required.