How to Install Exterior Light Posts

Dig a hole where you want to install the light post with a post hole digger to a diameter of 12 inches and a depth of 24 inches. Pour crushed gravel into the hole to a depth of 8 inches to provide drainage and prevent frost heaving.

Dig a trench 6 inches wide and 18 inches deep for the electrical wiring from the post hole to your home or garage in the vicinity of the breaker box. Place a length of 12-gauge electrical wire rated for direct burial into the bottom of the trench. Route the wire from the trench to the center of the post hole. Allow an extra 8 to 10 feet of wire at the post hole to wire the lamp. Allow enough extra wire on the opposite end of the trench to reach inside the house or garage and to the breaker box.

Empty a bag of ready-mix concrete into a wheelbarrow. Add enough water to the concrete powder to give it a butter-like consistency. Mix the concrete mixture with a hoe. Pour the concrete into the post hole, ensuring that the wiring is sticking up from the center of the post hole through the concrete.

Lay the lamppost onto the ground next to the post hole. Measure up 12 inches from the bottom of the post and make a pencil mark. Route the excess wiring that protrudes through the concrete into the lamppost. Ensure that the wire comes completely to the top of the post. Rotate the post upward and push it into the concrete while it is still wet. Use a twisting motion, as you push the post downward into the concrete, until the pencil mark on the post is flush with the top of the post hole.

Allow the concrete to cure fully. Fill the trench where the wire was installed with the dirt removed from the trench.