So you’re ready to build a fence. You have selected a fence design, planned its layout, purchased materials and marked property and underground utility lines.
The first and most important step in building a fence is setting all the fence posts. Fence posts provide the base support and strength for the rest of the fence.
Posts are generally spaced six to eight feet apart. However, the fence style you select, the terrain, the purpose, gate locations and other factors will determine the best spacing – although they should always be as equally spaced as possible.
1. Plot posts
Outline the perimeter of your fence using string, chalk line or mason’s line, ensuring corners are square. Use spray paint or stakes to mark out all posts.
2. Dig holes
Using a hole auger or post hole (clamshell) digger, instead of a shovel, will create flat-walled, barrel-shaped holes. Posts need to be set below the frost line to prevent heaving. For regular privacy fences, holes need to be at least 36 inches deep or half the fence height, whichever is greater, plus six inches for base gravel. Lower fences will not likely need to be as deep (or you may use ground spikes instead). The width of the hole should be three times the width of the post – so 12 inches for a 4 x 4-inch post.
3. Add base
A gravel base allows for drainage and prevents moisture from rotting the base of the post. Add about three inches of gravel, tamp it down using a piece of lumber and repeat for a six-inch base layer.
4. Set corner posts
Start setting your corner and end posts, ensuring they are vertically plumb. Diagonally brace them well in two directions for support.
5. Fill holes
There are a number of options to consider for backfill materials. The main considerations are cost, strength and ease of use. Materials can include packed earth or gravel (good drainage, but less strong), concrete (good strength, but difficult to replace posts) and new innovative products like Fast 2K (quick and easy, but greater cost). Ensure there is a mound around the base that forces water away from the post.
6. Set other posts
With your string or line still in place, put other posts in place. To ensure a straight fence, the one post side should meet the line without moving it. When the post is plumb and braced, backfill as per the previous step.
One more thing to consider before you begin: Do you cut the post to size before or after it is set in place? While both are viable options, you must have precise and equal hole depths and consider uneven terrain if cutting before placement.
Posts provide the foundation for a fence that is strong, straight and level. Proper planning and careful execution