Setting the base of a fencepost in concrete is only one important factor in secure installation. Drainage options and resistance to lateral forces on the posts are also necessary to build a fence that will last for many years. Depending on your soil composition and the presence of rocks and roots, digging the posthole takes only minutes with a posthole digger. Gravel is placed in the bottom of the hole for drainage and the post is quickly plumbed and secured with dry concrete. The concrete slowly absorbs moisture from the soil, holding the post securely in place.
Instructions
1. Multiply the height of the desired above-ground portion of the post by 1.25 to determine the overall length of the fencepost.
2. Measure, mark and trim the post to that length with the saw.
3. Measure, from one end of the post, the length of the above-ground portion and mark the post. Measure the length of the below-ground portion of the post. Add 6 inches to that dimension to determine the depth of the posthole.
4. Dig the posthole, using a posthole digger. The hole should be about three times the diameter or width of the post. As you approach the desired depth of the posthole, slightly angle the posthole digger to flare the bottom of the hole, making the posthole roughly bell-shaped at the bottom.
5. Measure to ensure that the depth of the hole is equal to the length of the below-ground portion of the post, plus 6 inches.
6. Pour a few inches of gravel into the hole.
7. Measure and add gravel until the depth of the hole is equal to the length of the below-ground portion of the fencepost.
8. Place the bottom of the fencepost vertically in the hole, oriented as needed to attach rails, linking adjacent posts. Ask an assistant to ensure that the post is straight, using a carpenter's level.
9. Shovel a few inches of the concrete/sand mix into the hole, distributing it around the post so that the hole is approximately 1/3 full. Measure the depth of the hole. The depth, after the concrete is added, should be approximately 2/3 of the length of the below-ground portion of the post. After each addition of concrete, the post must be checked to make sure it is still vertical in two planes, or plumb.
10. Use the handle of the shovel to tamp the concrete.
11. Add a few more inches of concrete and measure the hole's depth again. The depth of the hole should be about 2/3 the length of the buried portion of the post. Tamp the concrete. Continue adding concrete and tamping until the concrete is at ground level.
Tags: install, fence, post, concrete, base, portion post, below-ground portion, depth hole, length below-ground, length below-ground portion, below-ground portion post