How to Install 4×4 Fence Posts

For best results, you should bury them to a level that is just beyond the depth of the frost line for your region of the country. This said, sometimes it is impractical or too expensive to buy very long fence posts. At a minimum, however, you should bury the post to at least half the depth of the length of post that will stick out of the ground. For example, with a 6 foot high fence, the post should be buried in the ground 3 feet. Even if you do not live in a deep frost-line area it is important to get this type of depth to prevent the 4×4 fence posts from leaning over due to wind forces. It is also important to use 4×4 lumber that is treated and rated for burying.

To install fence posts on a property line it is important to survey the property first, and understand the required setbacks specified by your local building codes. Once you know where you want to install your 4×4 fence posts, use a posthole digger to dig the holes. Alternatively you can use an auger to speed up the process of digging the fence post holes. Make sure you make the holes sufficiently wide enough for the posts, e.g. approximately 8-10 inches in diameter.

After digging a fence post hole, set a post into the center of it and use a 4 to 6 foot level to plumb the pole. Also make sure it is in line with the other fence posts. Using a string line along the length of the staked out fence line is helpful in positioning each fence post.

To hold the pole in place you can use either concrete or crushed gravel. If you are using concrete, make sure to mix it up after you have dug your post holes and are ready to install them. While holding the fence post plumb, and in-line with the other fence posts, have someone shovel in concrete or gravel into the hole. If you are using concrete, use an iron bar or shovel to work the concrete around the base of the fence post as you pour shovelfuls of concrete into the hole.

If you are using gravel, then tamp the gravel down every 6 inches or so, up the length of the hole. This will help to lock the fence post into place and prevent it from leaning later on.

After installing the fence post allow the concrete to fully dry, if using concrete, before installing the fence sections. Note that wind forces can put tremendous stresses on a fence post. Consider installing fences that allow air to quickly pass through the fence, e.g. a split rail fence, or a picket style fence with spaces in-between pickets.