Digging tools, drill, level, bucket, gravel, post (must be rot-resistant wood, rust-resistant metal, or an appropriate synthetic material), 2 x 4 braces, wood stakes, wood screws.
Whether you’re building a new fence or anchoring a play structure, setting the posts in concrete is the best way to make sure they’ll stand straight and true for many years. Fast-setting concrete is ideal for setting posts because there’s no mixing—you simply pour the dry concrete from the bag right into the hole, then add water. The concrete sets up in 20 to 40 minutes, so you can quickly move on to the next stage of the project (a great convenience when setting fence posts) or backfill the hole to finish the job. Under normal curing conditions, you can apply heavy weight to the post (a basketball backboard, for example) after just 4 hours.
The steps shown here can be used for all sorts of outdoor projects, like setting posts for mailboxes, lamps, and signs, plus flagpoles and uprights for sports and play equipment. For structural or load-bearing applications, such as concrete footings for deck posts, or for securing any post in sandy soil, follow the steps on pages 59 to 60, using concrete forms to build the footings or set the posts.
1. Dig the post hole, making it three times the width of the post and at a depth equal to 1/3 to 1⁄2 of the above-ground length of the post, plus 6" (right). For loose or sandy soil, using a tube form is recommended (left).
2. Pour 6" of gravel or crushed stone into the bottom of the hole. Compact and level the gravel using a post or 2 x 4.
3. Set the post in the hole. Attach angled 2 x 4 braces to two adjacent sides of the post using one screw for each brace. Drive a stake into the ground near the lower end of each brace.
4. Use a level to position the post plumb (perfectly vertical), checking on two adjacent sides with the level, then fasten the braces to the stakes.
5. Fill the hole with concrete up to 3 to 4" below the ground level. Add the recommended amount of water. After the concrete has set, backfill the hole with soil and/or sod.