How to Set Posts in Crushed Rock

Determine and mark the location for each post with a wood stakes. If you're building a pergola, each post must be placed exactly across from the corresponding post. For a fence, the posts must be aligned.

Dig the post hole with a post auger or a post hole digger. Dump the removed rocks into one bucket, and once you reach soil, dump the soil in another bucket. The hole should be as deep as one-third of the length of each post. Make the hole about 12 inches wide to fit the post and surrounding concrete. Continue digging until you confirm with a measuring stick that each post hole is the same depth.

Add 3 inches of crushed rock from the bucket into the bottom of the hole and tamp it with a tamper tool. Insert the post in the post hole and check that it's plumb with a post level and adjust as necessary. Brace the post with two stakes. Pound each into the ground 2 feet from the post, and then attach them to the post with a C-clamp.

Mix the concrete with the suggested amounts of water. Use a shovel to fill the hole around the post with concrete. Tamp the concrete down as it reaches the surface, then add more to form a mound around the post so water will run off. Check that it is level before continuing to the next post. Wait two days for the base to cure.