Install an Outdoor Light Post

• 1). Choose a location for the post, and dig a trench leading away from that spot to the depth of your electrical installation. Dig this trench 36 inches away from the post location, and then dig the post hole itself at 12 inches square by 14 inches deep. The reason you begin the electrical trench first is to reduce possible problems with walls collapsing when trenching away from an existing hole.
  
  
• 2). Center the larger piece of plywood on the light post base. Mark the plywood for the locations of all four bolt holes. (Some posts might have fewer bolts.) Use the 5/8-inch drill bit to drill the marks you just made. Use the larger wood bit to make a hole in the center of the plywood through which to extend the conduit.
  
  
• 3). Center the larger piece of plywood over the post hole. Drive a stake into the ground at the middle of each side of the plywood, turning the wide side of the stake against the plywood. These stakes are to keep the plywood from shifting to one side or another. Remove the piece of plywood without disturbing the stakes.
  
  
• 4). Cut the 12-inch piece of plywood to fit the width of your trench, and drill a hole with the larger wood bit for the lower end of the PVC to protrude through. Wedge the plywood firmly across the trench 6 inches from the post hole. Place the end of the PVC through the hole in the trench, and seal around the pipe with foam sealant. Keep the PVC in place until the sealant dries enough to hold it. Fill the trench on either side of the plywood.
  
  
• 5). Put the threaded ends of the anchor bolts through the large piece of plywood and install the nuts. Spray the threads with WD-40 to prevent concrete from sticking to the threads later.
  
  
• 6). Mix the concrete and pour it into the hole. The concrete should not fill the hole completely, but should be within 2 inches of the top of the hole. Tap or wiggle the anchor bolts into the concrete until the plywood slides over the PVC conduit. Continue working the bolts down until the plywood is flat on the ground and the anchor bolt nuts are flush with the top of the plywood. Tap the tops of the anchor bolts to help vibrate the concrete around them evenly.
  
  
• 7). Allow the concrete to set for at least 12 hours. Remove the anchor nuts, and then remove the plywood from the top. Stand the light post up so that the bolt holes in the base fit over the anchor bolts. Screw the bolts down only until they are snug. Allow the post to cure for three to five days and then tighten the nuts down properly. You might need to add washers under the post base in order to level it properly, so check the plumb of the post before tightening the nuts down completely.