How to Install Outdoor Deck Lighting Fixtures

Effective and practical outdoor deck lighting is one of the most important components of your deck, which serves many functional purposes such as a barbecue area on summer evenings. Properly placed outdoor deck lighting enhances the whole exterior of your house, and installing deck lighting fixtures is a moderately simple DIY project as long as you carefully follow the right instructions. 

Tools and Materials Needed

  • 110 volt outdoor power outlet
  • Deck lights
  • Electric drill with extension cord 
  • 3 inch drill bit
  • Tape measure 
  • Stapler or staple gun
  • Work gloves
  • Safety goggles
  • Electrical tape
  • 12 volt outdoor lighting wire
  • 7/8 inch spade drill bit
  • Low voltage transformer

Step 1 - Select and Prepare Lighting Supplies

Add up the total number of watts of each individual bulb in your set of deck lights and make a note of this; you will need it later. Check that you have a 110 volt power outlet outside where it can be used for your deck. If not, you will need to have an electrician install one for you. Compare the total wattage to will need for your deck lights to the capacity of the transformer. Some low voltage transformers experience voltage drop over a length of wiring. To prevent this from happening, select a transformer that has a slightly higher than required capacity.

Step 2 - Plan Deck Light Set-up 

Determine where your transformer will be installed, and measure the distance of each light from this point. It is recommended to purchase about 10% more outdoor lighting wire than is called for; it is better to end up with extra than with not enough. Decide where on your deck you will be installing the lights, and at what intervals. It may be helpful to mark each spot with a small chalk mark once you have planned this out.

Step 3 - Drill Holes for Deck Lights

Put on your safety goggles and use the 3 inch drill bit to cut flat bottomed holes at each point in your deck floor where you will be installing each light. Be sure to keep the drill perpendicular to the surface of the deck at all times, and do not allow the drill bit to go all the way through the wood. Once this is complete, use the 7/8 inch spade drill bit to make a hole through the center of each 3 inch flat bottom hole. It is important that these holes be accurate since they will be the wiring bases for each deck light.

Step 4 - Install Deck Lights

Place each deck light firmly in each hole, and make sure it is securely in place. Locate the lead wires for each light, and connect them to the 12 volt outdoor lighting wire from underneath your deck. Be sure to wrap each connection point with electrical tape for safety reasons. Run the wires under the deck to your transformer and connect them according to specifications. Staple each wire at regular intervals along the underside of the deck, and be especially carefully not to run any staple through a wire; this can cause shorts and possibly a dangerous fire hazard.