Leveling a fence 101. ⬇️ Most ground isn’t perfectly flat, so each surface spacer needs to be adjusted to keep the bottom rail level. Some contractors start by setting a string line at the height where the top of the bottom rail should sit. Use a level to make sure the line is straight. Raise each surface spacer until its top touches the string line. Attach the spacer to the post using the provided 2 self-tapping screws. Repeat this process at the other end of the bottom rail. Use the string lin