How to Build a Fence Frame

Install Posts

• 1

  Measure, mark and trim the 4-by-4-inch fence posts. Fence posts are typically installed with one-fourth of their overall length buried underground. To calculate the overall length of the post, multiply the above-ground height of the post by 1.33. Divide the overall length of the post by 4 to calculate the length of the buried portion of the post.

• 2

  Mark the ground with sticks or stones where you intend to install the posts. Use a post hole digger to dig the post holes. The post holes should be approximately two and a half to three times as wide as the posts and 6 inches deeper than the buried portion of the post. Alternately dig, then measure, until the hole reaches the proper depth. When the hole has reached the proper depth, angle the post hole digger a few degrees to widen the bottom of the hole, making it bell shaped.

• 3

  Shovel 4 or 5 inches of crushed granite or pea gravel into the first post hole. Tamp the gravel with a shovel handle. Alternately add gravel, tamp and measure until the hole is the same depth as the buried portions of the posts.

• 4

  Place the first post in the prepared hole. Instruct an assistant to orient the post and use a carpenter's level to hold the post plumb in two planes as you backfill with dry concrete mix. Fill the hole around the post about half full with concrete. Tamp the dry mix with a shovel handle. Fill the hole to about an inch below ground level, then tamp. Backfill the top of the hole with soil. This final step will help to prevent frost heave. Install remaining fence posts in this manner.

Add Rails

• 5

  Mark the first installed post where you intend to position the lower edges of the rails. Tie a string to the upper mark. Extend the string to the last installed post in the line of posts. Pull the string taut, then wrap it around the post at approximately the same height as it was tied on the first post. Hang a line level on the string. Raise or lower the string until it is level. Tie the string around the end post. Mark each post where it is crossed by the string. Repeat to mark the rail positions on the remaining posts. Remove the string.

• 6

  Measure and note the distance between the lateral centers of two adjacent posts. Measure, mark and trim the rails for that fence section.

• 7

  Position the upper rail against the fence posts so a 4-inch surface is flush with the post and the lower edge of the rail is on the upper-rail reference marks. Center the ends of the rails to the posts. Instruct your assistant to hold the rail on the line as you screw your end of the rail to the post. Use a drill and driving bit to affix the rails to the posts with two evenly spaced decking screws, about 1 inch from the ends of the rails. Repeat to install remaining rails in the first fence section.

• 8

  Install remaining rails. The adjacent rails will be joined with butt joints in the centers of the posts.