Whether it is one post for a mailbox or 100 posts for a fence, it is important to follow some simple steps when setting a wooden post in the ground.
Step 1: Call (800) DIG-SAFE or dial 811 before you dig any hole. Depth and location of utility lines vary dramatically, so if you are digging more than 6 inches into the ground, call Dig Safe to have all the underground utilities marked in the area before your dig.
Step 2: Dig a hole equal to one-quarter the length of the post and approximately three times the width of the post. Make sure the hole you dig is slightly larger at the bottom than it is at the top. An inverted V-shaped hole will reduce the chance of frost and winter freezes pushing the post up and out of the ground.
Step 3: Dig the hole an additional 6 inches deeper and back-fill it with crushed stone or gravel. This will ensure proper drainage and limit long-term damage to the post.
Step 4: Set the post in the hole and brace the post by using two angled pieces of 2-by-4 lumber attached on adjacent sides of the post. Drive a stake into the ground next to the lower portion of each brace.
Step 5: Use a level to assure the post is vertically level (or plumb). Once the post is in position and level, nail or screw each brace to its corresponding ground stake. The braces will hold the post in place while you pour the concrete.
Step 6: Fill the post hole with dry-gravel mix or fast-setting concrete. Tamp the concrete into the hole until it is 3 to 4 inches below ground level. If possible, mound the dry mix around the base of the post to encourage ground moisture to run away from the post. Slowly pour in the recommended amount of water and allow the concrete to set.
Step 7: Once the concrete has thoroughly set, cover the concrete with dirt or mulch, remove the wooden braces and proceed with your project.