How to Build a Footing for a Fence

Calculate and note the burial depth of your post by dividing the above-ground height of the post by three. Once installed, one-fourth of the post will be buried. Measure and note the width of the post. The width of the post hole should be roughly three times the width of the post.

Dig the post hole with a post-hole digger. The depth of the post hole is equal to the length of the buried portion of the post plus 6 inches. As you dig the post hole periodically measure its depth with a yardstick. Once the post hole reaches the necessary depth, angle the post-hole digger 20 to 30 degrees to widen the bottom of the hole, making it bell-shaped.

Pour gravel into the hole, about 3 inches deep. Tamp the gravel with the handle of the shovel. Measure the depth of the hole. Add more gravel, then tamp and measure until the post hole depth is equal to the length of the buried portion of the post.

Place the post in the hole, aligned and oriented to the adjacent posts. Ask an assistant to plumb the post and hold it in place as you shovel concrete mix around the post. Your assistant must use a carpenter's level to frequently check and ensure that the post is vertical in two planes and adjust the position of the post as necessary. Shovel dry concrete mix around the post until the hole is about half full. Tamp the concrete mix with the shovel handle. Water the concrete mix so there is about 1 inch of standing water on the mix.

Fill the hole completely with concrete mix. Carefully shovel additional concrete mix around the base of the post to form a mound about 3 inches high and the same width as the post hole. Sprinkle water on the concrete mound. Used gloved hands to pack the wet concrete around the base of the post. The concrete mound will divert precipitation to help prevent the post from prematurely rotting.